Qualification: 
Ph.D
b_shantanu@cb.amrita.edu

Dr. Shantanu Bhowmik is the Head of the Research and Projects at School of Engineering and Professor at the Department of Aerospace Engineering at School of Engineering, Amrita Vishwa Vidyapeetham, Coimbatore, India.

Dr. Shantanu Bhowmik received his Ph. D. in Mechanical Engineering from Indian Institute of Technology (IIT) Roorkee and part of his Ph.D. thesis was carried out at Technical University of Berlin, Germany. Before joining at Amrita University, Dr. Bhowmik has worked as Associate Professor at Department of Aerospace Engineering, Delft University of Technology, Netherlands, Senior Scientist at Agency for Science Technology and Research (A*STAR) under Govt. of Singapore and Scientist at Royal Military College of Canada (under National Defence of Canada).

He has been honored by a number of international and national research awards such as prestigious International Scientific Exchange Research Award of Swiss National Science Foundation of Federal Government of Switzerland in April 2018. This program provides outstanding academicians/researches as Visiting Professorship in Swiss Universities. Awarded Achrya Prafulla Chandra Roy Research award from Institute of Palmocare, Kolkata, India in August 2017. Research Award of Swiss National Science Foundation of Federal Government of Switzerland in February 2016. This program provides outstanding academicians/researches as Visiting Professorship in Swiss Universities. Marie Curie Research Award from European Union 7th Framework Program from European Commission in February 2014. Brain Pool Korea Research Award from Korean Federation of Science and Technology Societies, Government of Korea in July 2013 for his exemplary work. This program provides outstanding academicians/researches as Adjunct Professorship in Korean Universities. DST-DAAD PPP-2000 Research Award during his doctoral research and part of the doctoral research was carried out at Technical University of Berlin, Germany, Natural Science and Engineering Research Council (NSERC) Visiting Fellow Research Award of Government of Canada as one of the most promising and emerging scientists and the work was carried out at Royal Military College of Canada (under National Defence of Canada) and the Research Award of Prestigious National Academies (National Research Council of USA) for NASA’s Vision of Space Exploration to work at NASA-Marshal Space Flight Centre.

Dr. Bhowmik has published over 135 research articles in polymeric composite, nano composite adhesive bonding and surface engineering related to aviation, space and nuclear applications in international journals and international conferences, 3 book chapters, filed 5 patents and 7 invention disclosures and member of editorial boards of Journal of Aircraft and Spacecraft Science, International Journal of Surface Engineering and Materials Technology and Journal of New Dimensions of Science and Technology. He is an executive member of Asian Polymer Association, Member of American Institute of Aeronautics and Astronautics (AIAA), European Society of Composite Materials (ESCM), Advisor of number of International Conferences and Professional Technical Expert of Army Design Bureau, Govt. of India.

Dr. Bhowmik has presented research articles in leading international conferences and delivered invited lectures at various countries such as Germany, UK, Switzerland, Canada, USA, France, Netherlands, Belgium, Japan, South Korea, Austria, Spain, Bulgeria, Norway, Sweden, Singapore, Malaysia and India. He is an eminent speaker of Indian Society for Advancement of Materials and Process Engineering (ISAMPE) and Army Design Bureau. He is also having international collaborations with Department of Chemistry and Chemical Engineering, Royal Military College of Canada, Department of Aerospace Engineering, Korea Advanced Institute of Science and Technology (KAIST), South Korea, Department of Aerospace Engineering, Delft University of Technology, The Netherlands, Fraunhofer Institute of Technology, Bremen, Germany, University of Applied Sciences, Rapprswil, Switzerland, Massey University, New Zealand and University of Southern Queensland, Australia as Visiting Professor.

Dr. Bhowmik has established International Centre for Nano Technology and Applied Adhesion at Sikkim Manipal University, Sikkim, India, and his research articles have been cited by number of industries including Lockheed Martin (USA), Israel Aerospace Limited, Leoni Studer AG (Switzerland), Dutch Space (The Netherlands) and Ventracor Limited (Australia).

Under Dr. Bhowmik’s supervision six Ph.D. dissertations and twelve M. Tech. dissertations have been awarded. He is currently supervising five Ph.D. research scholars and one Post Doctoral research scholar and has number of national and international funded projects.

Research Projects

Year Title Sponsor
2018 High Temperature Thermoplastic Hybrid Composite for Higher Tensile Strength and Impact Resistance (Principal Investigator) Swiss National Science Foundation, Federal Govt. of Switzerland
2018 Development of Light Weight Bullet Proof Material (Principal Investigator) TDFS-DRDO, Govt. of India
2016 State of the Art Transparent High Performance Polymeric Nano Composite Windows for Green Buildings and Transportation's (Principal Investigator) Department of Science and Technology (DST), Govt. of India
2016 Development of Ultra High Performance Thermoplastic Polymeric Composite for Future Generation Unmanned Aviation and Hypersonic Aircraft (Principal Investigator) Swiss National Science Foundation, Federal Government  of Switzerland.
2015 Durability of High Performance Nano Adhesive Bonding of Aluminium under Aerospace Environments
(Principal Investigator)
Defence Research and Development Organization (DRDO), Govt. of India
2014 Development of Metal/Poly Ether Ether Ketone Hybrid Composite Laminates for Nuclear Waste Storage Containers (Co-Investigator) Bhabha Atomic Research Center, Govt. of India
2014 Development of Ulta High Temperature Resistance Polymeric Nano Composites for Long Distance Space Applications (Principal Investigator) ISRO, Govt. of India
2014 Development of Advanced Magnetic Filtration System for Industrial Lubricants (Scientist-In-Charge) European Commission FP7-PEOPLE-2013-IIF,
Grant Agreement No: PIIF-GA-2013-621974
2013 Investigation on Ultra High Temperature Resistant Nano Adhesive Bonding of Space Durable Polymer for Aviation and Space Applications (Principal Investigator) Korean Federation of Science and Technology Societies, Govt. of Korea
2013 Investigation on Effect of Space Radiations on Space Durable Polymeric Nano Composite for Future Generation Space Missions (Co-Investigator) Bhabha Atomic Research Center, Govt. of India
2013 Investigation on Carbon Nano Fiber Reinforced Polyether Ether Ketone/Polyether Imides as Polymer
Composite Container for Long Time Nuclear Waste Disposal (Principal Investigator)
Bhabha Atomic Research Center, Govt. of India
2012 Polymeric Composite Damage Repair (Principal Investigator) Science and Engineering Research Council, Govt. of Singapore
2012 High Performance Polymeric Nano Composite for Bio Medical applications (Principal Investigator) DBT, Govt. of India
2011 Polymer Scaffold for Tissue Engineering (Co-Investigator) DBT, Govt. of India
2010 Investigation on Ultra Light Weight High Performance Polymeric Nano Composite for Aviation and Space Applications (Collaborator) National Defence of Canada (Government of Canada)
2008 Design and Characterization of the Lightweight High Performance Composite Materials for Vibrations/Impact Damping (Qualified) European Commission: EU FP 7, Marie Curie Research Program
2008 Durability of Nano Adhesive Bonding of High Performance Polymer under Aerospace and Space Environments (Collaborator) Defence of Canada (Government of Canada)
2006 High Performance Nano Adhesive Bonding of Titanium for Aerospace Applications (Collaborator) National Defence of Canada (Government of Canada)
2005 Fire Resistant Polymeric Nano Composite for Aerospace Applications (Approved) NASA Marshal Space Flight Centre
2005 Effect of High Energy Radiation and Space Environments on High Performance Polymer - Carbon Fibre Nano Composite (Approved) NASA Marshal Space Flight Centre
2002 Studies on Durability of Adhesive Bonding of High Performance Polymer to Titanium for Space Applications Natural Science and Engineering Research Council, Government of Canada
1998 Characteristics of Adhesive Bonding of Polyolefin to Steel CSIR, Government of India

Publications

Publication Type: Journal Article

Year of Publication Publication Type Title

2018

Journal Article

S. P. Aadhy, T. Sinega, H., Karthikeyan, C., Pitchan, M. Kumar, and Shantanu Bhowmik, “Comparative Studies of Energy Saving Polymers and Fabrication of High Performance Transparent Polymer by Solvent Bonding”, Journal of Polymer Engineering, 2018.

2018

Journal Article

S. Ahmed and Shantanu Bhowmik, “Interpenetrating polymer network adhesive bonding of PEEK to titanium for aerospace application”, Journal of Polymer Engineering, 2018.[Abstract]


This investigation highlights the rationale of epoxy-novolac interpenetrating polymer network (IPN) adhesive bonding of low-pressure plasma treated polyether ether ketone (PEEK) to plasma nitrided titanium for aerospace application. Physico-chemical characterization of surface modified PEEK is carried out by surface energy measurement and X-ray photoelectron spectroscopy (XPS) analysis. Lap shear tensile tests are carried out to measure mechanical properties such as lap-shear tensile strength, Young's modulus, percentage elongation at break (% EB) and toughness of the adhesive bonded PEEK to titanium joint. XPS analysis reveals the presence of the oxygen (O) functional group into the plasma treated PEEK surface. This polar functional group O increases the surface energy on the plasma treated PEEK surface, and consequently, the adhesive bond strength is enhanced. The values of Young's modulus, % EB and toughness of epoxy-novolac IPN adhesive bonded plasma treated PEEK to plasma nitrided titanium are increased considerably in respect to epoxy-novolac IPN adhesive bonded untreated PEEK to untreated titanium joint. Therefore, the present investigation concludes that the adhesive bond strength not only depends on the surface characteristics of PEEK and titanium, but also on the cohesive properties of the adhesive. ©2018 Walter de Gruyter GmbH, Berlin/Boston 2018. More »»

2018

Journal Article

M. Remanan, Shantanu Bhowmik, Varshney, L., and Dr. Jayanarayanan K., “Tungsten carbide, boron carbide and MWCNT reinforced polyaryl ether ketone nanocomposites: Morphology and thermomechanical behavior”, Journal of Applied Polymer Science, p. 47032, 2018.[Abstract]


This study involves the development and thermo-mechanical characterization of the individual, binary, and ternary nanocomposites using radiation resistant fillers like boron carbide (B4C), tungsten carbide (WC), and functionalized multi-walled carbon nanotubes (F-MWCNT) in a high performance polymer, namely, poly aryl ether ketone (PAEK). Transmission electron microscopy studies revealed the distribution and dispersion of nanofillers in the matrix. It has been observed that the presence of WC and F-MWCNT in PAEK matrix significantly enhanced the tensile strength of the composite whereas B4C made it stiff and brittle in nature. The tensile property improvement caused by WC and F-MWCNT has been correlated with the tensile fracture surface morphology studies. Dynamic mechanical analysis provided insight into the positive effect of nanofillers in delaying the relaxation of polymer chains. The thermogravimetric analysis gave indications on the increase in the thermal stability of the nanocomposites with the increase of nanofillers content.

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2018

Journal Article

M. Remanan, Shantanu Bhowmik, Lalit Varshney, and Dr. Jayanarayanan K., “Poly(aryl ether ketone) based individual, binary and ternary nanocomposites for nuclear waste storage: mechanical, rheological and thermal analysis”, Materials Research Express, vol. 5, p. 105306, 2018.[Abstract]


In this study poly aryl ether ketone (PAEK) based nanocomposites containing multi walled carbon nanotubes, boron carbide and tungsten carbide nanofillers were irradiated with gamma rays of dosage 5000 kGy. These composites were prepared to estimate their potential in nuclear waste storage applications. The tensile properties, non destructive testing, rheological behavior and thermal properties of the composites were evaluated before and after gamma irradiation. The property variation after irradiation was influenced by the cross linking and chain scission of the polymer developed within the nanocomposites. In the tensile property analysis, the tensile modulus and the percentage elongation at break of all the nanocomposites were modified after gamma irradiation. Non destructive testing (NDT) showed all the samples were free from voids and cracks after gamma rays exposure. There was a slight decrease in the complex viscosity of the samples after irradiation indicating the predominance of the chain scission over cross linking. The decrease in melting temperature and the crystallization temperature of PAEK and the nanocomposites after irradiation suggested changes in the conformation of the polymer chains which was validated by the gel permeation chromatography (GPC) analysis. Even though the properties of the virgin PAEK were significantly reduced after gamma irradiation, the percentage reduction in the properties of polymer nanocomposites was not considerable especially with the ones reinforced with tungsten carbide.

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2018

Journal Article

D. Pius Joy and Shantanu Bhowmik, “Investigation on high performance polymeric nano composite to develop transparent windshield”, Journal Materials Today: Proceedings, 2018.

2018

Journal Article

S. Nair, Pitchan, M. Kumar, Shantanu Bhowmik, and Epaarachchi, J., “Development of high temperature electrical conductive polymeric nanocomposite films for aerospace applications”, Materials Research Express, 2018.[Abstract]


In this investigation, an effort has been made to develop an electrically conductive high performance thermoplastic polyetherimide (PEI) nanocomposite film by reinforcing carbon nano fibers (CNF). PEI reinforced with silver coated CNF nanocomposite films have been processed using a solution casting technique. The electrical conductivity of the nanocomposite films has been characterized using four-point probe test. The results reveal that there is significanrt increase in the electrical conductivity of the PEI /Ag coated CNF nanocomposite film when compared to that of unfilled PEI. Tensile test results showed that there is narginal improvement in the Ag coated CNF/PEI nanocomposite when compared to unfilled PEI films. Thermogravimetric (TGA) analysis shows that degradation properties of the Ag-coated CNF filled nanocomposite increases. Spectroscopical analysis spectrum confirms the reinforcing effectiveness of Ag-coated CNF in the PEI matrix. Scanning Electron Microscope (SEM) micrographs validated the dispersion of uncoated and coated CNF in the PEI matrix.

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2017

Journal Article

H. M. Sa Iqbal, Shantanu Bhowmik, and Benedictus, Ra, “Performance Evaluation of Polybenzimidazole Coating for Aerospace Application”, Progress in Organic Coatings, vol. 105, pp. 190-199, 2017.[Abstract]


In Present study, characteristic behavior of PBI as a protective coating for aircraft application is presented. Performance of PBI coating is evaluated after exposure to hot wet environment and liquid immersion. Critical properties including hardness, scratch resistance and adhesion of PBI coating are assessed and results are presented. M21 epoxy based carbon fiber composite is used as substrate material. Atmospheric pressure plasma treatment (APPT) is performed to prepare the surface of substrate prior to application of PBI coating. Lap shear tests demonstrate that APPT has improved the adhesion strength of PBI bonded joints to about 250%. SEM analysis shows that strong composite/coating interface resulted in cohesive failure of the bonded joints. Lap shear test results on conditioned samples reveal that composite bonded joints has depicted about 15% decrease in strength after exposure to hot/wet environment under the conditions of 80 °C and 95% relative humidity (RH). However, mode of failure of bonded joints has not changed even after 1000 h of conditioning. PBI coated samples were also immersed in water and Skydrol to evaluate the effect on hardness and scratch resistance of PBI coating. Scratch tests on conditioned samples reveal that the visco-elastic recovery has increased from 58% (unexposed sample) to 71% with PBI coated panel immersed in skydrol. However, no major effect on visco-elastic recovery is observed with the samples immersed in water and the sample conditioned in hot/wet environment. Nano-indentation test results indicate that PBI coated panel immersed in skydrol has not depicted any decrease in elastic modulus ad hardness; whereas coated panel immersed in water for 1000 h has shown a minor decrease in both modulus and hardness. All these results indicate that PBI coating has great potential to retain its properties under harsh environment and it can be used as protective coating for aerospace application. © 2017 Elsevier B.V.

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2017

Journal Article

V. Kumar Pateland and Shantanu Bhowmik, “Plasma Processing of Aluminium Alloys to Promote Adhesion: A Critical Review”, Journal of Review of Adhesion and Adhesives (2017)., 2017.

2017

Journal Article

G. Venkatesan, Jithin, P. V., Rajan, V. T., Kumar, M., Shantanu Bhowmik, Rane, R., and Mukherjee, S., “Effect of Titanium Nitride coating for improvement of fire resistivity of Polymer Composite for Aerospace Application”, Journal of Aerospace Engineering: Part G, 2017.

2017

Journal Article

S. Ahmed, Chakroborty, D., Shantanu Bhowmik, and Mukherjiee, S., “Physichochemical Characteristics of Solvent Vapor Bonded Polycarbonate”, Journal of Polymers and the Environment, 2017.

2017

Journal Article

Ajeesh G, Venugopal, S., Shantanu Bhowmik, Lalit Varshney, Kumar, V., and Mathew Abraham, “Effects of High Energy Radiation and Thermo-Chemical Environments on Polyetherimide Composites: Futuristic Approach to Nuclear Waste Storage”, International Journal of Nuclear Energy Science and Technology, 2017.

2017

Journal Article

Shantanu Bhowmik, Pitchan, M. Kumar, Dr. Meera Balachandran, and Abraham, M., “Process Optimization of Functionalized MWCNT/Polyetherimide Nanocomposites for Aerospace Application”, Journal of Materials and Design, 2017.

2017

Journal Article

Shantanu Bhowmik, M, G. Ganesh, K, L., A, K. K., Ajeesh G, Epaarachchi, J. Ananda, and Yuan, X., “Electrically Conductive Nano Adhesive Bonding: Futuristic Approach for Satellites and Electromagnetic Interference Shielding”, Advances in Aircraft and Spacecraft Science, An International Journal, 2017.

2017

Journal Article

M. Remanan, Dr. Kannan M., Rao, R. Subba, Shantanu Bhowmik, Lalit Varshney, Mathew Abraham, and Dr. Jayanarayanan K., “Microstructure Development, Wear Characteristics and Kinetics of Thermal Decomposition of Hybrid Nanocomposites Based on Poly Aryl Ether Ketone, Boron Carbide and Multi Walled Carbon Nanotubes”, Journal of Inorganic and Organometallic Polymers, pp. 1–15, 2017.[Abstract]


In the present study a high performance polymer poly aryl ether ketone (PAEK) is reinforced with micro and nano boron carbide (B4C) and functionalized multi walled carbon nanotubes (F-MWCNT) to investigate the individual and hybrid effect of the fillers. Optical microscopy and transmission electron microscopy suggested the dispersion of micro and nano fillers respectively in PAEK matrix. The inclusion of B4C nano fillers increased the hardness of the composites which aided the wear resistance of the composites. The morphological features of the worn surface of the samples are analyzed using scanning electron microscopy. It is found from the izod impact test analysis that the impact strength of the composite enhanced by the F-MWCNT inclusion. The thermal properties of PAEK in the composites are studied using differential scanning calorimetry and it revealed dominant effect of F-MWCNT influencing the thermal transitions than the B4C particles. The kinetics of thermal degradation of various composites is analyzed using Coats–Redfern method. The positive influence of B4C in the matrix indicates that the thermal degradation is delayed due to the higher activation energy it possesses. The overall results shows that the hybrid nanocomposite exhibits better properties compared to individual micro and nano composites.

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2017

Journal Article

Shantanu Bhowmik, K, S., Kumar, S., Krishnan, Y., Kumar, P., and Ahmed, S., “Effect of TiN-Deposition on Adhesion Characteristics of Aluminium”, Journal of Surface Engineering, 2017.

2017

Journal Article

Shantanu Bhowmik, S. Ahmed, Chakroborty, D., and Mukherjee, S., “Characteristics of Simultaneous Epoxy-Novolac Full Interpenetrating Polymer Network (IPN) Adhesive”, Journal of Adhesion Science and Technology, 2017.

2016

Journal Article

D. Chakroborty, Ahamed, S., Shantanu Bhowmik, and Mukherjiee, S., “Adhesion Characteristics on Anodized Titanium and Its Durability under Aggressive Environments”, Journal of Surface Review and letters, 2016.

2016

Journal Article

Shantanu Bhowmik, Sharma, S. S., A.Nivetha, A., Maalavan, K., S. Subramanian, S., ,, Mohan, P., Ramanathan, S., Rane, R., and Mukherjee, S., “Novel Lightning Strike Protected Polymeric Composite for Future Generation Aviation”, Journal of Aerospace Engineering, 2016.

2016

Journal Article

H. Prakash, Shantanu Bhowmik, G. Ajeesh, and Thenarasu, M., “Novel Adhesion Promotion of Aluminium for Aviation Environments”, Journal of Surface Engineering and Applied Electrochemistry, 2016.

2016

Journal Article

V. J. Vijayan, A. Arun, Shantanu Bhowmik, M. Abraham, Ajeesh, G., and Pitchan M. K., “Development of lightweight high-performance polymeric composites with functionalized nanotubes”, Journal of Applied Polymer Science, vol. 133, p. 43471, 2016.[Abstract]


In this article, we highlight the various properties of an ultralightweight poly(ether ketone) (PEK) composite. In this study, special emphases were laid on the preparation of low-density, high-performance polymeric foams with foaming agents and activators. PEK, foamed PEK, and carbon nanotube (CNT)-reinforced foamed PEK composites were considered for this study. The density of the polymer decreased with the reinforcement of the foaming agent. We also noted that with the reinforcement of the modified CNT in the foamed PEK, there were marginal increases in the density and hardness of the composites. We also noted that the mechanical properties of the CNT-reinforced foamed PEK was on par with those of basic PEK. Thermogravimetric analysis gave us a clear indication that the thermal stability of the composites was not affected by the reinforcing foaming agent and nanoparticles. Scanning electron microscopy and transmission electron microscopy clearly indicated the formation of foams and also the dispersion of nanoparticles in the composite structure. We also observed that because of the reinforcement of multiwalled CNTs in the composite, there was an improvement in the hardness of the composite. An increase in the specific strength was observed in the foamed PEK composites. The CNT-reinforced foamed PEK showed a marginal decrease in the specific strength without a compromise in the impact strength. The impact strength of the CNT-reinforced foamed PEK composite was found to be similar to that of the basic PEK. © 2016 Wiley Periodicals, Inc.

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2016

Journal Article

H. M. S. Iqbal, Shantanu Bhowmik, and Benedictus, R., “Study the effect of Surface Morphology on Adhesion Properties of Polybenzimidazole Adhesive Bonded Composite Joints”, International Journal of Adhesion and Adhesives, 2016.

2016

Journal Article

A. .G, Shantanu Bhowmik, Venugopal Sivakumar, Lalit Varshney, Kumar, V., and Mathew Abraham, “Studies on Surface Activated Carbon Nano Fibre for In Situ High Performance Polymeric Nano Composites”, Journal of Composite Materials, 2016.

2016

Journal Article

M. Kumar Pitchan, Shantanu Bhowmik, Dr. Meera Balachandran, and Abraham, M., “Effect of Surface Functionalization on Mechanical Properties and Decomposition Kinetics of High Performance Polyetherimide/MWCNT Nano Composites”, Journal of Composites Part A Applied Science and Manufacturing, vol. 90, pp. 147-160, 2016.[Abstract]


In this investigation, Polyetherimide (PEI) reinforced with multi-walled carbon nanotube (MWCNT) using novel melt blending technique. Surface of MWCNTs are modified by acid treatment as well as by plasma treatment. PEI nano composites with 2 wt % treated MWCNT shows about 15 % improvement in mechanical properties when compared to unfilled PEI. The thermal decomposition kinetics of PEI/MWCNT nano composites has been critically analyzed by using Coats – Redfern model. The increase in activation energy for thermal degradation by 699 kJ /mol for 2 wt% MWCNT implies improvement in the thermal properties of PEI. Studies under Fourier Transform Infrared Spectroscopy (FTIR) and Transmission Electron Microscopy (TEM) depict significant interfacial adhesion with uniform dispersion of MWCNT in polymer matrix due to surface functionalization. 0.5 wt% chemically modified MWCNT shows typical alignment of MWCNT. There is a significant improvement in mechanical properties and thermal properties for surface functionalized MWCNT reinforced. More »»

2016

Journal Article

P. George, Mohan, P., Ajees, G., Sriram, K., Abraham, M., and Shantanu Bhowmik, “Novel High Performance Fire Resistant Polymer for Future Generation Aerospace”, Journal of Materials Design and Application, 2016.

2016

Journal Article

Shantanu Bhowmik and .G, A., “Feasibility of Polyetherketone (PEK) Composites: A Solution for Long Term Nuclear Waste Storage”, International Journal of Nuclear Energy Science and Technology, 2016.

2016

Journal Article

M. Remanan, Rao, R. S., Shantanu Bhowmik, Lalit Varshney, Mathew Abraham, and Dr. Jayanarayanan K., “Hybrid Nanocomposites based on poly aryl ether ketone, boron carbide and multi walled carbon nanotubes: Evaluation of thermo mechanical properties”, E-Polymers, vol. 16, pp. 493-503, 2016.[Abstract]


In this study an attempt has been made to incorporate a radiation resistant filler like boron carbide (B4C) nanopowder along with multi walled carbon nanotubes (MWCNT) in a high performance polymer namely poly aryl ether ketone (PAEK) for potential applications in the nuclear industry. The dispersion of nanofillers in PAEK was established by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Infra red (IR) spectroscopy indicated the interaction between functionalized MWCNT (F-MWCNT) and PAEK. The optimum combination of B4C and F-MWCNT was obtained from the tensile property analysis. It was found from the dynamic mechanical analysis that the storage modulus of the composite at elevated temperature was enhanced by B4C inclusions. Mechanical damping factor spectra showed the shift of PAEK glass transition temperature to higher values due to the presence of B4C and F-MWCNT. Thermogravimetric analysis (TGA) presented the resistance offered by B4C to the degradation of PAEK especially at elevated temperatures.

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2016

Journal Article

S. Ahmed, Chakraborty, D., Mukherjee, S., and Shantanu Bhowmik, “Characteristics of IPN Adhesive Bonding of Polyether Imide to Titanium for Aerospace Application”, Journal of Aerospace Engineering , 2016.

2015

Journal Article

Shantanu Bhowmik, Pratap, T., Kurup, D. A., .Thangaraj, G., Mukherjee, S., and Rane, R., “Titanium Nitride Deposition on Aluminium for Adhesion Promotion (Accepted)”, Journal of Surface Engineering, 2015.

2015

Journal Article

Sa Ahmed, Chakrabarty, Da, Shantanu Bhowmik, Mukherjee, Sd, and Rane, Rd, “Epoxy–novolac interpenetrating network adhesive for bonding of plasma-nitrided titanium”, Journal of Adhesion Science and Technology, 2015.[Abstract]


<p>This investigation highlights rationale to synthesize epoxy–novolac adhesive by novel interpenetrating network (IPN) technique. Physicochemical characteristics of the plain adhesive and IPN adhesive were carried out by Fourier transform infrared spectroscopy and thermal gravimetric analysis. Performing lap-shear test carried out plasma-nitrided titanium was fabricated with these adhesives and mechanical property of these adhesives. The blend of epoxy and novolac was optimized at 4:1 ratio, and the formation of IPN was confirmed by the suppression of creep with reference to neat epoxy and its swelling behavior. The adhesive with IPN shows significantly higher thermal stability than epoxy and leaves higher amount of residuals at the elevated temperature. Due to surface modification of titanium by plasma nitriding, wetting characteristics of titanium increases considerably and consequently, there was a significant increase in lap-shear strength adhesively of bonded titanium substrate. © 2015 Taylor &amp; Francis</p>

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2015

Journal Article

G. Ajeesh, Shantanu Bhowmik, Sivakumar, V., Lalit, V., Abrar, B., Yurim, P., Son, G., and Chun, G. Kim, “Influence of Chemically and Plasma Functionalized Carbon Nanotubes on High Performance Polymeric Nano Composites (Accepted)”, Journal of High Performance Polymers, 2015.

2015

Journal Article

M. Akram, K .M.B.Jansen, L .J.Ernst, Shantanu Bhowmik, G. Ajeesh, S. Ahmed, and D. Chakraborty, “Effect of Atmospheric Pressure Plasma Modification on Polyimide and Adhesive Joining with Titanium”, Journal of Metallurgical and Materials Transactions A , 2015.

2015

Journal Article

M. Akram, K. M. B. Jansen, L. J. Ernst, and Shantanu Bhowmik, “Atmospheric Plasma Modification of Polyimide Sheet for Joining of Titanium with High Temperature Adhesive”, International Journal of Adhesion and Adhesives, 2015.

2015

Journal Article

Sarath Kumar S., Abhishek G., Akhil Ullattil, Elangundran T.V.A, Shantanu Bhowmik, Saji Devadathan, Chun-Gon Kim, and Abrar Baluch, “Effect of Atmospheric Pressure Plasma Treatment for Repair of Polymer Composite for Aerospace Applications”, Journal of Composite Materials, 2015.

2015

Journal Article

Ahmed S., Chakrabarty D., Shantanu Bhowmik, and Mukherjee S., “Comparative Studies of Solvent Bonding and Adhesive Bonding for Fabrication of Transparent Polymer”, Journal of Surface Engineering and Applied Electrochemistry, 2015.

2015

Journal Article

I. H. M. S., Shantanu Bhowmik, and R., B., “Performance Evaluation of Polybenzimidazole Under High Energy Radiation Environment”, Journal of Thermophysics and Heat Transfer of American Institute of Aeronautics and Astronautics, 2015.

2015

Journal Article

Ajeesh G., Shantanu Bhowmik, Venugopal Sivakumar, Lalit Varshney, and Mathew Abraham, “Investigation on Polyetheretherketone Composite for Long Term Storage of Nuclear Waste”, Journal of Nuclear Materials, 2015.

2015

Journal Article

A. V. Akhil, Raj, D. D. D., Raj, M. K., Bhat, S. R., Akshay, V., Shantanu Bhowmik, Ramanathan, S., and Ahmed, S., “Vaporized solvent bonding of polymethyl methacrylate”, Journal of Adhesion Science and Technology, pp. 1–16, 2015.[Abstract]


This investigation highlights rationale of vaporized solvent bonding for fabrication of transparent polymers such as polymethyl methacrylate (PMMA) in terms of optical transparency and bond strength. Vaporized solvent bonding is employed to fabricate the polymer, and its bonding characteristics with appropriate solvents are analyzed. It is observed that chloroform exhibits superior bonding characteristics in comparison with other solvents such as acetone, ethanol, and dichloromethane. In order to see the effect of prior surface modification carried out by ultraviolet (UV) irradiation and low-pressure plasma, surface energy of the polymer was estimated. It is observed that due to surface modification of PMMA by UV irradiation and low-pressure plasma, surface energy of the polymer increases considerably. However, due to exposure under UV irradiation and low-pressure plasma, molecular weight of PMMA decreases and atomic force microscopy (AFM) studies reveal that the topography of PMMA changes significantly resulting in deterioration of vaporized solvent bonding strength. Therefore, in the case of vaporized solvent bonding, increase in surface energy of the polymer is not a primary factor rather retention of molecular weight is more necessary.

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2015

Journal Article

S. Ahmed, Chakrabarty, D., Shantanu Bhowmik, Mukherjee, S., and Rane, R., “Plasma nitriding on titanium surface for adhesion promotion”, Surface Engineering, vol. 31, pp. 616–622, 2015.[Abstract]


This investigation highlights the influence of plasma nitriding on titanium surface in order to improve its interfacial adhesion strength with epoxy and epoxy nanocomposites adhesive. Surface energy of titanium increases considerably due to plasma nitriding implantation. X-ray photoelectron spectroscopy studies indicate the formation of various titanium nitrides, which are responsible for the increase in surface polarity. A reduction in equilibrium contact angle improve wetting on the surface and proper intimacy of the adhesive layer with two joining titanium surfaces. The atomic force microscopic study indicates smoothening of treated titanium surface. Thus, a greater surface area of contact with the adhesive layer helps uniform splitting of adhesive over the two titanium surfaces. A further improvement in bond strength is achieved on incorporation of 5% nanosilicate as reinforcement within the adhesive. More »»

2014

Journal Article

S. Ahmed, Chakrabarty, D., Mukherjee, S., Joseph, A., Jhala, G., and Shantanu Bhowmik, “Investigation on nanoadhesive bonding of plasma modified titanium for aerospace application”, Journal of Advances Aircraft and Spacecraft Sciences , vol. 1, 2014.[Abstract]


Physico-chemical changes of the plasma modified titanium alloy [Ti-6Al-4V] surface were studied with respect to their crystallographic changes by X-Ray Diffraction (XRD) and Scanning Electron Microscope (SEM).The plasma-treatmentof surface was carried out to enhance adhesion of high performance nano reinforced epoxy adhesive, a phenomenon that was manifested in subsequent experimental results. The enhancement of adhesion as a consequence of improved spreading and wetting on metal surface was studied by contact angle (sessile drop method) and surface energy determination, which shows a distinct increase in polar component of surface energy. The synergism in bond strength was established by analyzing the lap-shear strength of titanium laminate. The extent of enhancement in thermal stability of the dispersed nanosilica particles reinforced epoxy adhesive was studied by Thermo Gravimetric Analysis (TGA), which shows an increase in onset of degradation and high amount of residuals at the high temperature range under study. The fractured surfaces of the joint were examined by Scanning electron microscope (SEM).

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2014

Journal Article

H. M. S. Iqbal, Stec, A. A., Patel, P., Shantanu Bhowmik, and Benedictus, R., “Study of the fire resistant behavior of unfilled and carbon nanofibers reinforced polybenzimidazole coating for structural applications”, Polymers for Advanced Technologies, vol. 25, pp. 29–35, 2014.[Abstract]


With increasing interest in epoxy-based carbon fiber composites for structural applications, it is important to improve the fire resistant properties of these materials. The fire resistant performance of these materials can be improved either by using high performance epoxy resin for manufacturing carbon fiber composite or by protecting the previously used epoxy-based composite with some fire resistant coating. In this context, work is carried out to evaluate the fire resistance performance of recently emerged high performance polybenzimidazole (PBI) when used as a coating material. Furthermore, the effect of carbon nanofibers (CNFs) on fire resistant properties of inherently flame retardant PBI coating was studied. Thermogravimetric analysis of carbon/epoxy composite, unfilled PBI and nano-filled PBI shows that the carbon/epoxy composite maintained its thermal stability up to a temperature of 400°C and afterwards showed a large decrease in mass, while both unfilled PBI and nano-filled PBI have shown thermal stability up to a temperature of 575°C corresponding to only 11% weight loss. Cone calorimeter test results show that unfilled PBI coating did not improve the fire retardant performance of carbon/epoxy composite. Conversely, nano-filled PBI coating has shown a significant improvement in fire retardant performance of the carbon/epoxy composite in terms of increased ignition time, reduced average and peak heat release rate and reduced smoke and carbon monoxide emission. These results indicate that addition of carbon nanofibers to inherently flame retardant coating can significantly be helpful for improving the fire resistance performance of composite materials even with low coating thickness.

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2014

Journal Article

H. M. S. Iqbal, Shantanu Bhowmik, and Benedictus, R., “Process optimization of solvent based polybenzimidazole adhesive for aerospace applications”, International Journal of Adhesion and Adhesives, vol. 48, pp. 188 - 193, 2014.[Abstract]


Abstract The use of adhesive bonding for high temperature applications is becoming more challenging because of low thermal and mechanical properties of commercially available adhesives. However, the development of high performance polymers can overcome the problem of using adhesive bonding at high temperature. Polybenzimidazole (PBI) is one such recently emerged high performance polymer with excellent thermal and mechanical properties. It has a tensile strength of 160 \{MPa\} and a glass transition of 425 °C. Currently, \{PBI\} is available in solution form with only 26% concentration in Dimethyl-acetamide solvent. Due to high solvent contents, the process optimization required lot of efforts to form \{PBI\} adhesive bonded joints with considerable lap shear strength. Therefore, in present work, efforts are devoted to optimize the adhesive bonding process of \{PBI\} in order to make its application possible as an adhesive for high temperature applications. Bonding process was optimized using different curing time and temperatures. Epoxy based carbon fiber composite bonded joints were successfully formed with single lap shear strength of 21 Mpa. \{PBI\} adhesive bonded joints were also formed after performing the atmospheric pressure plasma treatment of composite substrate. Plasma treatment has further improved the lap shear strength of bonded joints from 21 \{MPa\} to 30 MPa. Atmospheric pressure plasma treatment has also changed the mode of failure of composite bonded joints.

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2012

Journal Article

N. Bhatnagar, Jha, S., Shantanu Bhowmik, Gupta, G., Moon, J. B., and Kim, C. G., “Physico-chemical characteristics of high performance polymer modified by low and atmospheric pressure plasma”, Surface Engineering and Applied Electrochemistry, vol. 48, pp. 117–126, 2012.[Abstract]


In this work, the effect of low pressure plasma and atmospheric-pressure plasma treatment on surface properties and adhesion characteristics of high performance polymer, Polyether Ether Ketone (PEEK) are investigated in terms of Fourier Transform Infrared Spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and Atomic Force Microscopy (AFM). The experimental results show that the PEEK surface treated by atmospheric pressure plasma lead to an increase in the polar component of the surface energy, resulting in improving the adhesion characteristics of the PEEK/Epoxy adhesive system. Also, the roughness of the treated surfaces is largely increased as confirmed by AFM observation. These results can be explained by the fact that the atmospheric pressure plasma treatment of PEEK surface yields several oxygen functionalities on hydrophobic surface, which play an important role in increasing the surface polarity, wettability, and the adhesion characteristics of the PEEK/Epoxy adhesive system.

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2012

Journal Article

N. Bhatnagar and Shantanu Bhowmik, “High Performance Polymer in view of Emerging Technologies”, Polymer Society, vol. 4, pp. 30-31, 2012.

2012

Journal Article

H. M. S. Iqbal, Shantanu Bhowmik, Bhatnagar, N., Mondal, S., and S, A., “Adhesion Characteristic of High Temperature Resistant Polymer”, Journal of Adhesion Science and Technology, vol. 26, pp. 955-967, 2012.

2011

Journal Article

H. M. S. Iqbal, Shantanu Bhowmik, Benedictus, R., Moon, J. B., Kim, C. G., and Mourad, A. - H. I., “Processing and Characterization of Space-Durable High-Performance Polymeric Nanocomposite”, Journal of Thermophysics and Heat Transfer, vol. 25, pp. 87–95, 2011.[Abstract]


In this investigation, efforts were given to develop carbon-nanofiber- reinforced polybenzimidazol nanocomposite for space application. Processing of polybenzimidazol was carried out by using polybenzimidazol in powder and solution forms. Thermomechanical properties of compression-molded polybenzimidazol, unfilled polybenzimidazol films, and nanofiber-reinforced polybenzimidazol films were investigated using thermogravimetric analysis, dynamic mechanical analysis, and tensile testing. Thermogravimetric analysis revealed that both compressionmolded polybenzimidazol and polybenzimidazol films show high thermal stability. Dynamic mechanical analysis studies depicted that both compression-molded polybenzimidazol and polybenzimidazol neat films exhibited a high storage modulus, even at a temperature of 250°C. Polybenzimidazol nanocomposite films were cast with different loadings of carbon nanofibers from 0.5 to 2 wt%in polymer solution. Addition of carbon nanofibers improved the thermal stability and storage modulus of polybenzimidazol film. Mechanical testing showed that both compressionmolded polybenzimidazol and polybenzimidazol films resulted in the highest ultimate tensile strength in comparison to any unfilled polymer. Investigation under scanning electron microscopy confirmed uniform dispersion of carbon nanofibers in polymer solution. Analysis of fractured surfaces revealed that neat polybenzimidazol film exhibited ductile failure and dispersion of carbon nanofibers into the polybenzimidazol, resulting in transformation from ductile to brittle failure. Copyright © 2010 by the American Institute of Aeronautics and Astronautics, Inc

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2011

Journal Article

N. Bhatnagar, Pyngrope, D., Pradhan, iv, R., Jha, S., Shantanu Bhowmik, Poulis, H., Bui, V. Tam, and Bonin, H., “Electron beam modification of space durable polymeric nano-adhesive bonding of ultra-high temperature resistant polymer”, Journal of Polymer Engineering, vol. 31, pp. 381–386, 2011.[Abstract]


This investigation highlights fabrication of ultra-high temperature resistant polymers such as polybenzimidazole (PBI) by high-performance nano-adhesive. High-performance nano-adhesive is prepared by dispersing carbon nano-fibers into ultra-high temperature resistant epoxy adhesive. Prior to fabrication of PBI, the surface of PBI is ultrasonically cleaned by acetone and then modified by atmospheric pressure plasma with 30, 60 and 90 s of exposure and low-pressure plasma with 30, 60, 120, 240 and 480 s of exposure. Surface characterization of the unmodified and modified PBI sheets is carried out by contact angle measurements and surface energy of the polymer is estimated. It is observed that the polar component of surface energy leading to total surface energy of the polymer increases significantly when exposed to atmospheric pressure plasma. Tensile lap shear strength of adhesive bonded PBI reveals that atmospheric pressure plasma is more useful than low-pressure plasma in terms of adhesive bond strength of PBI and increases further when fabricated by nano-carbon fibers dispersed epoxy adhesive. The nano-adhesive bonded PBI sheets are post-cured by electron beam radiation under the SLOWPOKE-2 nuclear reactor. Post curing under electron beam radiation further increases the adhesive bond strength considerably. © 2011 by Walter de Gruyter Berlin Boston.

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2011

Journal Article

M. Akram, Jansen, K. M. B., Ernst, L. J., and Shantanu Bhowmik, “Atmospheric pressure plasma surface modification of titanium for high temperature adhesive bonding”, International journal of adhesion and adhesives, vol. 31, pp. 598–604, 2011.[Abstract]


In this investigation surface treatment of titanium is carried out by plasma ion implantation under atmospheric pressure plasma in order to increase the adhesive bond strength. Prior to the plasma treatment, titanium surfaces were mechanically treated by sand blasting. It is observed that the contact angle of de-ionized water decreases with the grit blast treatment time. Optical microscopy and scanning electron microscopic (SEM) analysis of untreated and atmospheric plasma treated titanium are carried out to examine the surface characteristics. A substantial improvement in the surface energy of titanium is observed after the atmospheric pressure plasma treatment. The surface energy increases with increasing exposure time of atmospheric pressure plasma. The optimized time of plasma treatment suggested in this investigation results in maximum adhesive bond strength of the titanium. Unmodified and surface modified titanium sheets by atmospheric pressure plasma were adhesively bonded by high temperature resistant polyimide adhesive. The glass transition temperature of this adhesive is 310 °C and these adhesively bonded joints were cured at high temperature. A substantial improvement in adhesive bond strength was observed after atmospheric pressure plasma treatment. © 2011 Elsevier Ltd. All rights reserved.

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2011

Journal Article

N. Bhatnagar, Jha, S., and Shantanu Bhowmik, “Energy dispersive spectroscopy study of surface modified PEEK”, Advanced Materials Letters, vol. 2, 2011.[Abstract]


PEEK (polyether etherketone) polymer, is increasingly used in many industrial applications as a replacement for metal components. In this investigation, attention is given to understand the chemical changes that have been introduced on the surface of PEEK, when surface of the PEEK is modified by low pressure plasma under RF (radio frequency) glow discharge. The contact angle measurements show that the contact angle decreases after the plasma treatment which results in the increase in surface energy. This paper also discusses the common surface characterisation technique like Energy Dispersive Spectroscopy (EDS) analysis to determine the chemical changes that have been introduced on the surface. Copyright © 2011 VBRI press.

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2011

Journal Article

J. - B. Moon, Kim, M. - G., Kim, C. - G., and Shantanu Bhowmik, “Improvement of tensile properties of CFRP composites under LEO space environment by applying MWNTs and thin-ply”, Composites Part A: Applied Science and Manufacturing, vol. 42, pp. 694–701, 2011.[Abstract]


Multi-wall carbon nanotube (MWNT) added carbon fiber reinforced plastics (CFRP) and thin-ply composites are suggested as solutions to improve resistance against low earth orbit (LEO) environment and mechanical properties. Accelerated ground simulation experiments were performed for CFRP, MWNT reinforced CFRP, thin-ply CFRP and MWNT reinforced thin-ply CFRP. The used ground simulation facility can simulate high vacuum, atomic oxygen, ultraviolet (UV) light and thermal cycling simultaneously. The aging experiment was performed for 20 h. After the aging experiment, total mass loss (TML) and tensile properties were measured. As a result, by applying thin-ply thickness and MWNT fillers, the tensile strength was improved at ground conditions. Under an LEO space environment, while thin-ply composites cannot relieve the degradation rate, the composites with MWNT can do so. Highly improved tensile strength was observed by simultaneously applying the thin-ply techniques and MWNT under both LEO aged and LEO non-aged conditions. © 2011 Elsevier Ltd. All rights reserved.

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2011

Journal Article

R. Pradhan, iv, Bhattacharyya, A. Shanker, Pramanik, N., Haldar, R., Niyogi, U. Kumar, Khandal, R. Kumar, and Shantanu Bhowmik, “Investigation on Nylon 66 silicate nanocomposites modified under gamma radiation”, Journal of Polymer Engineering, vol. 32, no. 6,7, pp. 379-388, 2011.[Abstract]


This investigation highlights the processing of Nylon 66 and the incorporation of nano-silicate into the Nylon 66 polymeric matrix. Further, radiation modification of Nylon 66 and nano-silicate dispersed Nylon 66 was carried out in order to essentially alter the physicochemical properties of the material. A combination of both the above methods of processing and modifying the neat Nylon 66 polymeric matrix provides an interesting aspect for studying the resultant effect on the variation in properties of the composite material over the virgin polymer. There was a significant improvement of physicothermal and physicomechanical properties when Nylon 66-silicate nanocomposites were further modified under gamma radiation, which was confirmed by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), tensile and water absorption studies.

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2010

Journal Article

H. M. S. Iqbal, Shantanu Bhowmik, and Benedictus, R., “Surface modification of high performance polymers by atmospheric pressure plasma and failure mechanism of adhesive bonded joints”, International Journal of Adhesion and Adhesives, vol. 30, pp. 418–424, 2010.[Abstract]


In this investigation, the effects of atmospheric pressure plasma treatment on the surface energy of polyetheretherketone (PEEK), carbon fibers (CF) and glass fiber (GF) reinforced polyphenylene sulfide (PPS) are studied. A substantial improvement in the surface energy of these materials is observed after the atmospheric plasma treatment. It is observed that the polar component of surface energy is responsible for the increase in total surface energy of these materials. To make a comparison of atmospheric plasma treatment and low pressure plasma treatment on the surface energy, PEEK surface is also modified by low pressure plasma. It is observed that the surface modification of polymer by atmospheric pressure plasma is more effective in comparison to low pressure plasma both in terms of improvement of surface energy and bonded joint strength. Scanning electron microscopy of untreated and atmospheric plasma treated specimens is carried out to examine the surface morphology. After atmospheric plasma treatment, increased surface roughness is observed which helps in improving the adhesion properties. The improvement in adhesion properties of these materials is correlated with lap shear strength of adhesive bonded joints. Bonded joints are fabricated by employing recently developed ultrahigh temperature resistant epoxy adhesive. Tensile lap shear testing is also carried out using PPS-CF and PPS-GF as substrate materials. Lap shear tests results for these materials show three to four times improvement in joint strength after atmospheric plasma treatment. Finally, the fractured surfaces of the joints were examined by scanning electron microscope to understand the failure mechanism.

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2010

Journal Article

H. M. S. Iqbal, Shantanu Bhowmik, Poulis, J. A., and Benedictus, R., “Effect of plasma treatment and electron beam radiations on the strength of nanofilled adhesive-bonded joints”, Polymer Engineering & Science, vol. 50, pp. 1505–1511, 2010.[Abstract]


This investigation highlights the adhesion performance of carbon fiber- and glass fiber-reinforced polyphenylene sulfide when joined by high-performance neat epoxy adhesive and nanofilled epoxy adhesive. A significant increase in the surface energy of these materials is observed after the surface modification with atmospheric plasma treatment. An increase in surface roughness is observed after exposing the surface to plasma. Lap shear testing of untreated and plasma-treated joints is carried out to correlate the improvement in adhesion properties with the joint strength. A considerable increase in joint strength is observed when the surfaces of these materials are modified by atmospheric pressure plasma. There is a further increase in joint strength when the composites are joined by nanofilled epoxy adhesive, and subsequent exposure to electron beam radiations results in minor increase in the joint strength. Finally, the fractured surfaces of the joints are examined and the analysis is performed. POLYM. ENG. SCI., 50:1505–1511, 2010. © 2010 Society of Plastics Engineers

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2010

Journal Article

M. I. Faraz, Shantanu Bhowmik, De Ruijter, C., Laoutid, F., Benedictus, R., Dubois, P., Page, J. V. S., and Jeson, S., “Thermal, morphological, and mechanical characterization of novel carbon nanofiber-filled bismaleimide composites”, Journal of applied polymer science, vol. 117, pp. 2159–2167, 2010.[Abstract]


Novel carbon nanofiber (CNF) -filled bis- malemide composites were fabricated by a thermokinetic mixing method. The thermal and mechanical properties of composites containing 1 wt % and 2 wt % CNFs were investigated. Thermogravimetric analysis demonstrated that minimal improvement in thermal stability of the nanocomposites was obtained by the addition of CNFs. Dynamic mechanical analysis showed an increase in storage modulus (E′) and glass transition temperature (Tg) upon incorporation of nanofibers. Limiting oxygen index (LOI) has also been found to increase with incorporation of CNFs. Morphological studies of fractured surfaces of the composites has been carried out by scanning electron microscopy to determine the effect of fiber content and dispersion on the failure mechanism. In general, good dispersion was observed, along with agglomeration at some points and some fiber matrix interfacial debonding. A decrease in mechanical strength has been observed and debonding was found as the main failure mechanism. Further research outlook is also presented. © 2010 Wiley Periodicals, Inc.

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2010

Journal Article

N. Bhatnagar, Jha, S., and Shantanu Bhowmik, “APPLICATION OF HIGH PERFORMANCE POLYMER-POLYETHERETHERKETONES (PEEK) IN AEROSPACE INDUSTRY”, Inventi Impact: Tech Research & Reviews, vol. 1, no. 1, 2010.[Abstract]


Presently, polymers are playing a significant role in aerospace research world over. However, the use of polymeric materials in primary structures of aerospace is still limited due to the high temperatures encountered by the aerodynamic heating in the case of aerospace. Therefore, thermoplastic materials are often used to replace parts of the engine which are traditionally constructed from metals. PEEK ( poly ether ether ketone) polymer, is increasingly used in the aerospace industry as a replacement for metal components, because it combines all these characteristics with easy processability.This paper mainly deals with the different properties of PEEK and the need for modifying its surface which can further enhance its adhesion characteristics.

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2010

Journal Article

S. Jha, Shantanu Bhowmik, Bhattacharya, N., Bhatnagar, N., and Deka, U., “Experimental investigation into the effect of Adhesion Properties of High Performance Polymer Modified by Atmospheric Pressure Plasma and Low Pressure Plasma: A comparative Study”, Journal of Applied Polymer Science , vol. 118, pp. 173 - 179, 2010.

2010

Journal Article

N. Bhatnagar, Shantanu Bhowmik, and Jha, S., “Surface characterization techniques for measuring the chemical state & elemental composition of polymeric surfaces”, International Journal of EmergingTechnologies and Applications in Engineering Technology and Sciences, vol. 3, pp. 490-493, 2010.

2010

Journal Article

N. Bhatnagar, Jha, S., and Shantanu Bhowmik, “Surface Characterization of Polymeric Composites Modified by Plasma Technique – A Review”, Journal of Technology and Engineering Sciences, vol. 3, 2010.

2009

Journal Article

Shantanu Bhowmik, Benedictus, R., Poulis, H., Bonin, H., and Bui, V. Tam, “High-performance nanoadhesive bonding of space-durable polymer and its performance under space environments”, Journal of Spacecraft and Rockets, vol. 46, pp. 218–224, 2009.[Abstract]


The present investigation highlights fabrication of polybenzimidazole by high-performance nanoadhesive and its performance under space environments. High-performance nanoadhesive is prepared by dispersing silicate nanopowder into ultra-high-temperature-resistant epoxy adhesive. The surface of polybenzimidazole is ultrasonically cleaned by acetone and then modified by low-pressure plasma before bonding. Electron spectroscopy for chemical analysis reveals that the polymer surface becomes hydrophilic, resulting in an increase in surface energy. Thermogravimetric analysis studies show that the cohesive properties of nanoadhesive are more stable when heated up to 350°C. The adhesive joint strength of surface-modified polybenzimidazole increases considerably, and there is a further significant increase in joint strength when it is prepared by nanosilicate epoxy adhesive. When the nanoadhesive joint of polybenzimidazole is exposed to the safe-low-power critical-experiment nuclear reactor, there is a considerable increase in joint strength up to a dose of 444 kGy and then a decrease. When the join ts are exposed to cryogenic (-196°C) and elevated temperatures (+300° C) for 100 h and thermal-fatigue conditions, the joint could retain 95 % of the joint strength. The failure mode of the surface-modified polymer is cohesive within the adhesive.

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2009

Journal Article

H. W. Bonin, Benedictus, R., Poulis, J. A., Bui, V. T., and Shantanu Bhowmik, “High Performance Nano Adhesive Bonding of Titanium for Aerospace and Space Applications”, International Journal of Adhesion and Adhesives, vol. 29, no. 3, pp. 259-267, 2009.[Abstract]


In this investigation, attempts are made to prepare high-performance nanoadhesive bonding of titanium for its essential applications to aviation and space. The high-performance nanoadhesive is prepared by dispersing silicate nanoparticles into the ultra-high-temperature-resistant epoxy adhesive at 10 wt% ratio with the matrix adhesive followed by modification of the nanoadhesive after curing under high-energy radiation for 6 h in the pool of SLOWPOKE-2 nuclear reactor with a dose rate of 37 kGy/h to promote crosslink into the adhesive. Prior to bonding, the surfaces of the titanium sheets are mechanically polished by wire brushing, ultrasonically cleaned by acetone and thereafter the titanium sheets are modified by plasma ion implantation using plasma nitriding. The titanium surface is characterized by X-ray photoelectron spectroscopy (XPS). The thermal characteristics of the epoxy adhesive and the high-performance nanoadhesive are carried out by thermal gravimetric analysis (TGA). The TGA studies clearly shows that for the basic adhesive there is a weight loss of the adhesive, however, in the case of epoxy–silicate nanoadhesive, there is almost 100% retention of weight of the adhesive, when the adhesive is heated up to 350 °C. Lap shear tensile strength of the joint increases considerably, when the titanium surface is modified by plasma-nitriding implantation. There is a further massive increase in joint strength, when the plasma-nitriding implanted titanium joint is prepared by nanosilicate–epoxy adhesive and further modification of the adhesive joint under high-energy radiation results a further significant increase in joint strength. In order to simulate with aviation and space climatic conditions, the joints are separately exposed to cryogenic (−196 °C) and elevated temperature (+300 °C) for 100 h and thermal fatigue tests of the joints are carried out under 10 cycles by exposing the joint for 2 h under the above temperatures. When the joint completely kept at ambient condition and the joint strength compared with those joints exposed to aviation and space climatic conditions, it is observed that the joint could retain 95% of the joint strength. Finally, to understand the behavior of the high-performance silicate–epoxy nanoadhesive bonding of titanium, the fractured surfaces of the joints are examined by scanning electron microscope.

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2008

Journal Article

Shantanu Bhowmik, Benedictusa, R., Poulisa, J. A., Boninb, H. W., and Buib, V. T., “Influence of Mixed Field Radiation and Gamma Radiation on Nano Adhesive Bonding of HP Polymer”, Journal of Polymer Engineering, vol. 28, pp. 225–242, 2008.[Abstract]


In this investigation, attempts are made to fabricate high performance polymer such as polybenzimidazole (PBI) (service temperature ranges from 260°C to +500°C) by nano silicate epoxy adhesive and to see its performance under space radiation. The polybenzimidazole sheets are fabricated by high performance nano adhesive i.e., by dispersing silicate nano powder into the ultra high temperature resistant epoxy adhesive (DURALCO 4703, the service temperature of the adhesive is -260°C to +350°C) with 2 to 20% weight ratios with the matrix adhesive. Prior to fabrication of polybenzimidazole sheet, the surface of the polybenzimidazole is ultrasonically cleaned by acetone followed by its modification through low-pressure plasma by using 13.56 MHz RF Glow Discharge with 30, 60, 120, 240 and 480 seconds at 100 W of power using nitrogen as process gas. It is observed that polar component of surface energy leading to total surface energy of the polymer increases with exposure time of low pressure plasma up to 120 seconds and then it saturates. Nano adhesive bonding of high performance polymer is exposed to two types of radiations (i) mixed field radiation for 24 hours at a dose rate of 37kGy/hr in the pool of a SLOWPOKE-2 (safe low power critical experiment) nuclear reactor and (ii) Co-60 irradiation with 100 % gamma radiation at a dose rate of 4 kGy/hr for 60 hours. Tensile lap shear strength reveals that when the polymer surface is modified by low pressure plasma, joint strength increases from 1 MPa to 13 MPa and increases further up to 23 MPa when the polymer is fabricated by nano silicate epoxy adhesive with increasing weight ratios of silicate nano powder up to 10% and then it deteriorates with the increasing weight ratio of silicate nano powder. When this nano silicate epoxy adhesive joint is exposed to high-energy radiation of mixed field, there is a further considerable increase in joint strength up to 30 MPa. However, when the nano silicate epoxy adhesive joint is exposed to 100 % gamma rays condition, joint strength deteriorates. Therefore, this is possible that mixed field radiation; basically increase the crosslink density of the adhesive resulting in increase in adhesive joint strength and in the second case: gamma radiation is detrimental and which could essentially makes chain scission to the basic adhesive and resulting in significant deterioration of joint strength. Finally, to understand the behaviour of nano silicate epoxy adhesive bonding of Polybenzimidazole, the fractured surfaces of the joints are examined by scanning electron microscope.

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2008

Journal Article

I. J. Kim, Kim, C. G., Moon, J. B., and Shantanu Bhowmik, “Effects of LEO Environment Factors on ILSS of MWNT Reinforced CFRP Composites”, Journal of Materials Korea, vol. KSAS08 3127, pp. 394-397, 2008.

2008

Journal Article

K. P. Ghatak, Bhattacharya, S., Shantanu Bhowmik, Benedictus, R., and Choudhury, S., “Thermoelectric power in carbon nanotubes and quantum wires of nonlinear optical, optoelectronic, and related materials under strong magnetic field: Simplified theory and relative comparison”, Journal of Applied Physics, vol. 103, pp. 034303-034024, 2008.[Abstract]


We study thermoelectric power under strong magnetic field (TPM) in carbon nanotubes(CNTs) and quantum wires (QWs) of nonlinear optical, optoelectronic, and related materials. The corresponding results for QWs of III-V, ternary, and quaternary compounds form a special case of our generalized analysis. The TPM has also been investigated in QWs of II-VI,IV-VI, stressed materials,n-GaP, p-PtSb2, n-GaSb, and bismuth on the basis of the appropriate carrier dispersion laws in the respective cases. It has been found, taking QWs of n-CdGeAs2, n-Cd3As2, n-InAs, n-InSb, n-GaAs, n-Hg1−xCdxTe, n-In1−xGaxAsyP1−y lattice-matched to InP,p-CdS, n-PbTe, n-PbSnTe, n-Pb1−xSnxSe, stressed n-InSb, n-GaP, p-PtSb2, n-GaSb, and bismuth as examples, that the respective TPM in the QWs of the aforementioned materials exhibits increasing quantum steps with the decreasing electron statistics with different numerical values, and the nature of the variations are totally band-structure-dependent. In CNTs, the TPM exhibits periodic oscillations with decreasing amplitudes for increasing electron statistics, and its nature is radically different as compared with the corresponding TPM of QWs since they depend exclusively on the respective band structures emphasizing the different signatures of the two entirely different one-dimensional nanostructured systems in various cases. The well-known expression of the TPM for wide gap materials has been obtained as a special case under certain limiting conditions, and this compatibility is an indirect test for our generalized formalism. In addition, we have suggested the experimental methods of determining the Einstein relation for the diffusivity-mobility ratio and the carrier contribution to the elastic constants for materials having arbitrary dispersion laws.

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2008

Journal Article

K. P. Ghatak, Bhattacharya, S., Shantanu Bhowmik, Benedictus, R., and Choudhury, S., “The Einstein relation in quantum wires of III-V, ternary, and quaternary materials in the presence of light waves: Simplified theory, relative comparison, and suggestion for experimental determination”, Journal of Applied Physics, vol. 103, p. 094314, 2008.[Abstract]


We study the Einstein relation for the diffusivity to mobility ratio (DMR) in quantum wires (QWs) of III-V, ternary, and quaternary materials in the presence of light waves, whose unperturbed energy band structures are defined by the three band model of Kane. It has been found, taking n-InAs, n-InSb, n-Hg1−xCdxTe, n-In1−xGaxAsyP1−y lattice matched to InP as examples, that the respective DMRs exhibit decreasing quantum step dependence with the increasing film thickness, decreasing electron statistics, increasing light intensity and wavelength, with different numerical values. The nature of the variations is totally band structure dependent and is influenced by the presence of the different energy band constants. The strong dependence of the DMR on both the light intensity and the wavelength reflects the direct signature of the light waves which is in contrast as compared to the corresponding QWs of the said materials in the absence of photoexcitation. The classical equation of the DMR in the absence of any field has been obtained as a special case of the present analysis under certain limiting conditions and this is the indirect test of the generalized formalism. We have suggested an experimental method of determining the DMR in QWs of degenerate materials having arbitrary dispersion laws and our results find six applications in the field of quantum effect devices.

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2006

Journal Article

Shantanu Bhowmik, Bonin, H. W., Bui, V. T., and Chaki, T. K., “Physicochemical and adhesion characteristics of high-density polyethylene when treated in a low-pressure plasma under different electrodes”, The Journal of Adhesion, vol. 82, pp. 1–18, 2006.[Abstract]


The present investigation studys the effects of different electrodes such as copper, nickel, and stainless steel under low-pressure plasma on physicochemical and adhesion characteristics ofhigh-density polyethylene (HDPE). To estimate the extent of surface modification, the surface energies of the polymer surfaces exposed to low-pressure plasmas have been determined by measuring contact angles using two standard test liquids of known surface energies. It is observed that the surface energy and its polar component increase with increasing exposure time, attain a maximum, and then decrease. The increase in surface energy and its polar component is relatively more important when the polymer is exposed under a stainless-steelelectrode followed by a nickel and then a copper electrode. The dispersion component of surface energy remains almost unaffected. The surfaces have also been studied by optical microscopy and electron spectroscopy for chemical analysis (ESCA). It is observed that when the HDPE is exposed under these electrodes, single crystals of shish kebab structure form, and the extent of formation of crystals is higher under a stainless-steel electrode followed by nickel and then copper electrodes. Exposure of the polymer under low-pressure plasma has essentially incorporated oxygen functionalities on the polymer surface as detected by ESCA. Furthermore the ESCA studies strongly emphasize that higher incorporation of oxygen functionalities are obtained when the polymer is exposed to low-pressure plasma under a stainless-steel electrode followed by nickel and then copper electrodes. These oxygen functionalities have been transformed into various polar functional groups, which have been attributed to increases in the polar component of surface energy as well as the total surface energy of the polymer. Therefore, the maximum increase in surface energy results in stronger adhesion of the polymer when the polymer is exposed under a stainless-steel electrode rather than nickel and copper electrodes.

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2006

Journal Article

Shantanu Bhowmik, Bonin, H. W., Bui, V. T., and Weir, R. D., “Modification of high-performance polymer composite through high-energy radiation and low-pressure plasma for aerospace and space applications”, Journal of applied polymer science, vol. 102, pp. 1959–1967, 2006.[Abstract]


In this investigation, attempts are made to modify a high-performance polymer such as polybenzimidazole (PBI) (service temperature ranges from −260°C to +400°C) through high-energy radiation and low-pressure plasma to prepare composite with the same polymer. The PBI composites are prepared using an ultrahigh temperature resistant epoxy adhesive to join the two polymer sheets. The service temperature of this adhesive ranges from −260°C to +370°C, and in addition, this adhesive has excellent resistance to most acids, alkalis, solvents, corrosive agents, radiation, and fire, making it extremely useful for aerospace and space applications. Prior to preparing the composite, the surface of the PBI is ultrasonically cleaned by acetone followed by its modification through high-energy radiation for 6 h in the pool of a SLOWPOKE-2 (safe low power critical experiment) nuclear reactor, which produces a mixed field of thermal and epithermal neutrons, energetic electrons, and protons, and γ-rays, with a dose rate of 37 kGy/h and low-pressure plasma through 13.56 MHz RF glow discharge for 120 s at 100 W of power using nitrogen as process gas, to essentially increase the surface energy of the polymer, leading to substantial improvement of its adhesion characteristics. Prior to joining, the polymer surfaces are characterized by estimating surface energy and electron spectroscopy for chemical analysis (ESCA). To determine the joint strength, tensile lap shear tests are performed according to ASTM D 5868–95 standard. Another set of experiments is carried out by exposing the low-pressure plasma-modified polymer joint under the SLOWPOKE-2 nuclear for 6 h. Considerable increase in the joint strength is observed, when the polymer surface is modified by either high-energy radiation or low-pressure plasma. There is further significant increase in joint strength, when the polymer surface is first modified by low-pressure plasma followed by exposing the joint under high-energy radiation. To simulate with spatial conditions, the joints are exposed to cryogenic (−196°C) and high temperatures (+300°C) for 100 h. Then, tensile lap shear tests are carried out to determine the effects of these environments on the joint strength. It is observed that when these polymeric joints are exposed to these climatic conditions, the joints could retain their strength of about 95% of that of joints tested under ambient conditions. Finally, to understand the behavior of ultrahigh temperature resistant epoxy adhesive bonding of PBI, the fractured surfaces of the joints are examined by scanning electron microscope. It is observed that there is considerable interfacial failure in the case of unmodified polymer-to-polymer joint whereas surface-modified polymer essentially fails cohesively within the adhesive. Therefore, this high-performance polymer composite could be highly useful for structural applications in space and aerospace.

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2006

Journal Article

Shantanu Bhowmik, Bonin, H. W., Bui, V. T., and Weir, R. D., “Durability of adhesive bonding of titanium in radiation and aerospace environments”, International journal of adhesion and adhesives, vol. 26, pp. 400–405, 2006.[Abstract]


In this investigation, attempts have been made at understanding the effects of high-energy radiation, low and high temperatures on adhesive bonding of titanium (ASTM F 67–95 Grade 2). Two titanium sheets are joined by a ceramic adhesive (Resbond™ 907 GF). The service temperature of this adhesive ranges from –185 to +1290 °C and, in addition, this adhesive has excellent resistance to most acids, alkalies, solvents, corrosive agents and fire, and, therefore, is extremely useful for aerospace applications. Prior to joining, the surfaces of the titanium sheets are mechanically polished by wire brushing, cleaned by isopropanol and then modified by sodium hydroxide anodization. First, to determine the joint strength under ambient conditions, tensile lap shear test are performed according to the ASTM D 5868-95 standard. Then the joints are exposed to aggressive chemical environments. It is observed that the joint strength decreases drastically for those joints prepared without modifying the titanium surface by sodium hydroxide anodization. However, the titanium surface modified by sodium hydroxide anodization and joined are able to retain about 70% of their strength. These joints are then irradiated for 6 h at a dose rate of 37 kGy/h in the pool of a SLOWPOKE-2 nuclear reactor, which produces a mixed field of thermal and epithermal neutrons, energetic electrons and protons and gamma rays. It is observed that under this exposure, the joint strength remains almost unaffected. In order to simulate the service conditions of aerospace applications, the joints are also exposed to low temperature (−80 °C) and elevated temperature (+500 °C) for 100 h. It is observed that in these cases, the joints retained the strength of about 95% in respect to the strength of the joint tested under ambient conditions. Failures of the joints are observed as primarily cohesively within the adhesive. Therefore, this adhesive bonding of titanium is a very good candidate for structural applications in aerospace.

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2005

Journal Article

Shantanu Bhowmik, “Studies on the Effects of Welding Speed and Welding Heat on Depth of HAZ and Penetration in Single Run Submerged ARC Automatic Square Butt Welding”, Journal of A. E., vol. 75, 2005.

2004

Journal Article

Shantanu Bhowmik, Chaki, T. K., Ray, S., Hoffman, F., and Dorn, L., “Effect of surface modification of high-density polyethylene by direct current and radio frequency glow discharge on wetting and adhesion characteristics”, Metallurgical and Materials Transactions A, vol. 35, pp. 865–877, 2004.[Abstract]


The present investigation aims to optimize the process parameters of Direct Current (DC) and Radio Frequency (RF) glow discharge treatment through air in terms of discharge power and time of exposure for the surface modification of high-density polyethylene (HDPE) sheet, for attaining best adhesive joint of the polymer to mild steel. In order to estimate the extent of surface modification, the surface energies of the polymer surfaces exposed to glow discharge have been determined by measuring contact angles using two standard test liquids of known surface energies. It is observed that at a given power level of DC glow discharge, surface energy and its polar component increase with increasing exposure time, attaining a maximum and then decreasing. In the case of RF glow discharge, surface energy and its polar component increase with increasing exposure time and then saturate. Surface modification by DC glow discharge increases the surface energy of HDPE relatively more at a lower power compared to that observed for RF glow discharge. The dispersion component of surface energy remains almost unaffected. The surfaces have also been studied by electron spectroscopy for chemical analysis (ESCA) and energy-dispersive spectra (EDS). A significant oxygen peak is observed for surface-modified polymer as detected by ESCA and EDS. Lap shear tensile test of an adhesive (Araldite AY 105) joint of HDPE with mild steel has been carried out in optimizing the parameters of DC and RF glow discharge for maximum joint strength. When HDPE is exposed to DC glow discharge, improvement of adhesive joint strength of HDPE to mild steel is found to be by a factor more than 7. On the other hand, when HDPE is exposed to RF glow discharge, results in improvement of adhesive joint strength of HDPE to mild steel by a factor nearer to 7 are found. Thus, DC glow discharge is more capable for increasing wetting and adhesion characteristics of the polymer.

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2004

Journal Article

Shantanu Bhowmik, Jana, P., Chaki, T. K., and Ray, S., “Surface modification of PP under different electrodes of DC glow discharge and its physicochemical characteristics”, Surface and Coatings Technology, vol. 185, pp. 81–91, 2004.[Abstract]


The present investigation aims to study the wetting and physicochemical characteristics of Polypropylene (PP) sheet when exposed to a DC glow discharge through air across different electrodes such as copper, nickel and stainless steel at 13 W power level of DC glow discharge under an electrode size of 64 cm2. In order to estimate the extent of surface modification, the surface energies of the polymer surfaces exposed to DC glow discharge have been determined by measuring contact angles using two standard test liquids of known surface energies. It is observed that surface energy and its polar component increases with increasing exposure time, attains maximum and then decreases. The increase in surface energy and its polar component is relatively higher when the polymer is exposed under stainless steel electrode followed by nickel and then copper electrode. The dispersion component of surface energy remains almost unaffected. The surfaces have also been studied by optical microscopy and electron spectroscopy for chemical analysis (ESCA). It is observed that when the PP is exposed under these electrodes, single crystals of shish kebab structure forms and the extent of formation of crystals are higher under stainless steel electrode followed by nickel and then copper electrodes. Exposure of the polymer under DC glow discharges has essentially incorporated oxygen functionalities on the polymer surface as detected by ESCA. It is noted that higher incorporation of oxygen functionalities have been obtained, when the polymer is exposed to DC glow discharge under stainless steel electrode followed by nickel and copper electrodes as evident from ESCA studies. These oxygen functionalities have been transformed into various polar functional groups and which has been attributed to increase the polar component of surface energy of the polymer. Therefore, maximum increase in surface energy is obtained when the PP sheet is exposed under a stainless steel electrode rather than nickel or copper electrodes.

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2004

Journal Article

Shantanu Bhowmik, Chaki, T. K., Ray, S., Hoffman, F., and Dorn, L., “Experimental investigation into the effect of DC glow discharge pretreatment of HDPE on tensile lap shear strength”, International journal of adhesion and adhesives, vol. 24, pp. 461–470, 2004.[Abstract]


The present investigation aims to optimise the process parameters of DC glow discharge treatment through air in terms of discharge power and time of exposure for attaining best adhesive joint of high-density polyethylene (HDPE) to mild steel. The as- received and DC glow discharge exposed HDPE surfaces have been characterised by energy dispersive spectra (EDS). It is observed that with increasing power level up to 13 W, tensile lap shear strength of adhesive (Araldite AY 105) joint of HDPE to mild steel increases and then decreases. At 13 W power level, joint strength increases up to 120 s of exposure and then decreases. At the optimised condition for the surface modification, the effect of two different adhesives Araldite AY 105 and Araldite 2011 on the strength of polymer to mild steel, polymer to polymer and mild steel to mild steel joints have been examined. It is observed that tensile lap shear strength of HDPE–HDPE joint and HDPE–mild steel joint does not change with the change of adhesive and this could be possible as initiation of fracture takes place from subsurface layer of the polymer. This is confirmed by studies under optical microscopy and EDS, which shows when the polymer has been modified by exposure under glow discharge the failure is observed to initiate from subsurface layer of the HDPE, then within the adhesive cohesively and thereafter in the mild steel to adhesive interface.

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2001

Journal Article

Shantanu Bhowmik, Ghosh, P. K., and Ray, S., “Surface modification of HDPE and PP by mechanical polishing and DC glow discharge and their adhesive joining to steel”, Journal of applied polymer science, vol. 80, pp. 1140–1149, 2001.[Abstract]


To improve the strengths of the adhesive joints of high density polyethylene (HDPE) and polypropylene (PP) to steel, the surfaces of HDPE and PP sheets have been treated by DC glow discharge to increase the polar component of surface energy significantly. Present study investigates the effect of mechanical polishing prior to surface modification of substrates of HDPE and PP sheets by exposure to DC glow discharge, on the surface energy and their adhesive joint strength to steel. The mechanical polishing has been carried out by abrading with 120, 220, 400, 600, 800, and 1000 grade emery paper of grit sizes 8.33, 4.54, 2.5, 1.67, 1.2, and 1 micron, respectively. The surface energy of a given surface has been evaluated by measuring contact angles of sessile drops of two test liquids of known surface tension components, such as deionized water and formamide. It is observed that 800-grade emery paper of grit size 1.2 micron has been found most effective in terms of their reduction in contact angles and enhancement of their surface energies. The change in surface energy due to surface modification has also been evaluated by measuring the surface energies of unpolished sheets exposed to DC glow discharge. The surface modification of the polymers by glow discharge for 120 s at a power level of 13 W decreases the contact angle more on mechanically polished specimens than that observed on unpolished sheets. Due to glow discharge treatment, the polar component of surface energy increases significantly in HDPE and PP, especially when they are mechanically polished (800 grade) prior to glow discharge. However, in case of the HDPE sheets, the effect of glow discharge on the polar component of surface energy is significantly higher compared to that for dispersion component of surface energy, whereas the polar component of surface energy of the PP sheet is lower than the dispersion component of surface energy. But in both the cases, mechanical polishing prior to glow discharge appears to affect the polar component of surface energy. Mechanical polishing of the HDPE and PP sheets by abrading with 800-grade emery paper prior to glow discharge treatment, increases the adhesive joint strengths over those observed in case of unpolished polymers exposed to glow discharge. However, the use of prior mechanical polishing increases the joint strength only by a little more than 10% compared to a five to seven times increase in strength observed as a consequence of exposure to glow discharge of as received samples.

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1998

Journal Article

Shantanu Bhowmik, Ghosh, P. K., Ray, S., and Barthwal, S. K., “Surface modification of high density polyethylene and polypropylene by DC glow discharge and adhesive bonding to steel”, Journal of adhesion science and technology, vol. 12, pp. 1181–1204, 1998.[Abstract]


The surface modification of high density polyethylene (HDPE) and polypropylene (PP) has been carried out by exposure to a DC glow discharge in air at different power levels of 5.28, 11, and 13 W. The surface energies of polymers exposed to glow discharge were estimated by measuring the contact angles of two test liquids: de-ionized water and formamide, whose surfaceenergy components are known. Both the polar and the dispersion components of the surfaceenergy increased rapidly at short exposure times but the increase of the polar component was relatively more than that of the dispersion component. At low power levels of 5.28 and 11 W, the polar component of the surface energy reached a maximum plateau depending on the exposure time, but at a 13 W power level the polar component of the surface energy decreased from a maximum value to a saturation level. For PP, this saturation level could not be attained in this study. The maximum total surface energy measured in this study corresponds to the maximum polar component at 13 W for an exposure time of 120 s. The contact angle of the adhesive, Araldite AY 105 mixed with hardener HY 840 in a weight ratio of 2 : 1, was minimum at this maximum surface energy attained with HDPE and PP by exposure to a glow discharge in air. The measured lap shear strengths of HDPE or PP-Araldite-mild steel joints show a maximum corresponding to the maximum surface energy measured on the above-mentioned polymers.

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Publication Type: Patent

Year of Publication Publication Type Title

2017

Patent

Shantanu Bhowmik, Govindaraju, M., Ajeesh G, and Sivakumar, V., “Development of Light Weight Blast Proof Composite for Aviation, Space and Defence Structural Applications”, U.S. Patent 2017410463972017.

2016

Patent

Shantanu Bhowmik, “High Temperature Thermoplastic Carbon Fabric Composite”, 2016.

2016

Patent

Shantanu Bhowmik, P Kumar, M., Barandun, G. Andrea, and Zullig, M., “High Performance PEI-Carbon Composite for Aerospace Structurals”, 2016.

2008

Patent

Shantanu Bhowmik and Aaldert, P. J., “Method for Treatment of a Surface Area of Steel”, 2008.[Abstract]


The invention relates to a method for treatment of a surface area of steel by polishing said surface area and performing a plasma treatment of said surface area wherein the plasma treatment is performed at at least atmospheric conditions and wherein the plasma treatment is carried out at a power of approximately 300 W and for a duration of at least 20 minutes, and preferably 30 minutes

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2008

Patent

Shantanu Bhowmik, Poulis, J. A., and Benedictus, R., “Epoxy-resin adhesive and method for bonding using such an epoxy resin adhesive”, U.S. Patent PCT/EP2008/0554492008.[Abstract]


The invention relates to an epoxy resin adhesive comprising a dotation of nano-substances, wherein the nano- substances are selected from the group comprising carbon-fibre nanotubes, carbon nano-fibres, silicate nano powders, and wherein the nano-substances are dispersed in the adhesive with a weight ratio of at least 1% and wherein the nano-substances are carbon-fibre nanotubes having a weight ratio of approximately 2%.

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2008

Patent

Shantanu Bhowmik, “High Performance Polymer Single Wall Carbon Nanotube Composites for Potential Application to Spacecrafts and Defence Electronics”, 2008.

Publication Type: Conference Paper

Year of Publication Publication Type Title

2016

Conference Paper

Shantanu Bhowmik, Ajeesh G, Venugopal Sivakumar, Lalit Varshney, and Mathew Abraham, “Investigation on High Performance Polymers for Long Term Storage of Nuclear Waste”, in 4th International Conference on Nano and Materials Engineering (ICNME 2016), Bali, Indonesia., 2016.

2016

Conference Paper

Shantanu Bhowmik and Santosh, B., “High Performance Nano Adhesive Bonding for Future Generations Aviation and Defence”, in International Conference on Energy, Functional Materials and Nanotechnology (ICEFN-2016), Kumaun University, Nainital, 2016.

2014

Conference Paper

Shantanu Bhowmik, “Advanced Polymer Composite for Aviation and Space (Invited Speaker)”, in Program of 2014 Winter Workshop on Space Structures of Structures Division of Korean Society for Aeronautical and Space Sciences, Korea Advanced Institute of Science and Technology, 2014.

2014

Conference Paper

S. Ahmed, Mukherjee, S., Shantanu Bhowmik, and Chakraborty, D., “High Performance Laminar Nanocomposite of Plasma Modified Titanium for Aerospace Application”, in Global Conference on Polymer and Composite Materials (PCM 2014), Ningbo, China, 2014.

2014

Conference Paper

S. Ahmed, Shantanu Bhowmik, Chakraborty, D., Mukherjee, S., K. M. B. Jansen, and Akram, M., “Polyimide to Titanium Composite for Aviation and Space Applications”, in ISAMPE National Conference on Composites, INCCOM – 13, Vikram Sarabhai Space Center (VSSC), Thiruvananthapuram, India, 2014.

2013

Conference Paper

S. Ahmed, Ayan, D., Mukherjee, S., Shantanu Bhowmik, and Chakraborty, D., “Plasma Modified Metal Laminar Nano Composite for Adhesion Promotion”, in 4th International Conference on Recent Advances in Composite Materials (ICRACM 2013), International Centre, Goa, India, 2013.

2013

Conference Paper

Shantanu Bhowmik, “Effect of Radiation and Vacuum on Space Durable Polymeric Nano Composite and Adhesive Bonding”, in International Conference on Advancements and Futuristic Trends in Mechanical and Materials engineering, Punjab Technical University, 2013.

2011

Conference Paper

S. Mukherjee, S, A., Shantanu Bhowmik, and Chakraborty, D., “A Novel Approach For The Fabrication of High Performance Titanium Laminate For Aerospace Application”, in 12th World Conference on Titanium Ti-2011, Beijing, China, 2011.

2011

Conference Paper

S. Mondal, Shantanu Bhowmik, and Khandal, R. K., “Influence of Multi Walled Carbon Nanotube on Thermal Conductivity of Polypropylene Glycol”, in Advances in Polymer Science and Rubber Technology (APSRT 2011); Challenges towards 2020 and beyond, Indian Institute of Technology (IIT) Kharagpur, India, 2011.

2011

Conference Paper

Shantanu Bhowmik, “Characterization of Ultra High Temperature Resistant Polymer for Space Applications (Invited Author)”, in National Workshop on Recent Advances in Thermal Analysis of Polymers and Composites , Indian Institute of Technology, 2011.

2011

Conference Paper

Shantanu Bhowmik, Khandal, R. K., and Pradhan, R., “Investigation on Nylon 66 Silicate Nanocomposites Modified under Gamma Radiation”, in Advances in Polymer Science and Rubber Technology (APSRT 2011); Challenges towards 2020 and beyond, Indian Institute of Technology (IIT) Kharagpur, India, 2011.[Abstract]


This investigation highlights the processing of Nylon 66 and the incorporation of nano-silicate into the Nylon 66 polymeric matrix. Further, radiation modification of Nylon 66 and nano-silicate dispersed Nylon 66 was carried out in order to essentially alter the physicochemical properties of the material. A combination of both the above methods of processing and modifying the neat Nylon 66 polymeric matrix provides an interesting aspect for studying the resultant effect on the variation in properties of the composite material over the virgin polymer. There was a significant improvement of physicothermal and physicomechanical properties when Nylon 66-silicate nanocomposites were further modified under gamma radiation, which was confirmed by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), tensile and water absorption studies.

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2011

Conference Paper

S. Ahmed, Ayan, D., Joseph, A., Jhala, G., Mukherjee, S., Chakraborty, D., and Shantanu Bhowmik, “A Novel Approach For The Fabrication of High Performance Titanium Alloy Laminate For Aerospace Application”, in 12th World Conference on Titanium 2011 (ti - 2011), 2011.

2010

Conference Paper

R. Benedictus, Iqbal, H. M. S., Shantanu Bhowmik, Poulis, J. A., and Akram, M., “State of the Art Space Durable Polymeric Nano Composite and its Fabrication by Nano Adhesive Bonding”, in 2nd Indo Swiss Bonding International Symposium, Sikkim, India, 2010.

2010

Conference Paper

C. G. Kim, Kim, I. J., Moon, J. B., and Shantanu Bhowmik, “The Effect of Simulated Hypervelocity Impact on MWNT reinforced CFRP Composite induced by Simulated LEO Space Environment”, in 2nd Indo Swiss Bonding International Symposium, Sikkim, India, 2010.

2010

Conference Paper

S. Jha, Bhatnagar, N., Shantanu Bhowmik, Bhattacharya, N. K., and Choudhury, A., “Surface Modification for Adhesion Enhancdement on Nano Adhesive Bonded High Performance Polymer”, in 2nd Indo Swiss Bonding International Symposium, Sikkim, India, 2010.

2010

Conference Paper

M. Akram, Jansen, K. M. B., Ernst, L. J., and Shantanu Bhowmik, “Surface Modification of Polyimide by Atmospheric Pressure Plasma for Adhesive Bonding with Titanium and its Application to Aviation and Space”, in SAMPE USA 2010 Conference and Exhibition, Seattle, WA, USA, 2010.[Abstract]


It is noted that in search of long term and efficient service performance in the context of future generation of aerospace materials, there is increasing need of metal-high performance polymer composite. Based on these considerations, high temperature resistant polymeric sheet such as Polyimide Meldin7001 sheet, is joined with Titanium sheet by employing ultra high temperature resistant Polyimide adhesive. In order to increase surface energy of Polyimide surface, atmospheric pressure plasma treatment is used to modify the Polyimide surface. Atmospheric pressure plasma treatment creates physical and chemical changes such as cross linking, formation of free radicals and oxygen functionalization in the form of polar groups on polymer surface resulting in improvement of wetting and adhesion characteristics. Surface of Polyimide (PI) sheet is treated with atmospheric pressure plasma for different exposure periods. Surface energy of PI sheet increases with increase in exposure time. However, after a certain exposure time of plasma, deterioration of surface layer of PI substrate results in degradation and embitterment of PI which is not suitable for adhesive bonding. Optical microscopic, SEM (EDS), analysis of treated and untreated specimen is carried out to examine the surface characteristics. Treated samples and untreated samples of Polyimide are bonded together with overlap joints. Lap shear bond strength of treated and untreated samples was measured by tensile test to study the effect of treatment on adhesive bond strength. The optimized time of plasma treatment suggested in this investigation results in maximum adhesive bond strength and consequently, this technology is highly acceptable for aviation and space applications.

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2010

Conference Paper

Shantanu Bhowmik, “Performance of Space Durable Polymeric Nano Composite under Space Radiation at Geosynchronous Earth Orbit (Invited Author)”, in International Conference on RADIATION PROCESSING: Value addition for Food, Agro, Healthcare and Other Industrial Products , New Delhi, India, 2010.

2010

Conference Paper

S. Jha, Shantanu Bhowmik, and Bhatnagar, N., “Adhesion Enhancement and Thermal Properties of Nano Adhesive Bonded High Performance Polymer”, in International Conference on Recent Advances in Chemical Sciences (ICRACS-10), Pt. Ravishankar Shukla University, Raipur, India , 2010.

2009

Conference Paper

H. M. S. Iqbal, Shantanu Bhowmik, and Benedictus, R., “Development of Nanofibers Reinforced Polymer Composite for Space Application”, in 17th International Conference on Composite Materials, ICCM-17, Edinburgh, United Kingdom, 2009.[Abstract]


In this study, efforts are made to develop carbon nanofibers (CNFs) reinforced Polybenzimidazol (PBI) nanocomposite to resist high energy radiations in harsh space environment. Thermal analysis shows that PBI has the highest glass transition temperature among high performance polymers and it has substantial thermal stability. Tensile test results show that neat PBI has very high tensile strength and Young's modulus. Improvement in thermal and mechanical properties is observed after the addition of 2% CNFs in the PBI polymer.

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2009

Conference Paper

Shantanu Bhowmik, Bhattacharya, N. K., Deka, U., Jha, S., Iqbal, H. M. S., and Faraz, M. I., “Comparative Studies of Adhesion Properties of High Performance Polymer Modified by Atmospheric Pressure Plasma and Low Pressure Plasma (Invited Author)”, in SWISSBONDING 09: 25th International Congress of Adhesion and Bonding Technology, Lake of Zurich, Switzerland, 2009.

2009

Conference Paper

M. Akram, Benedictus, R., Shantanu Bhowmik, and Poulis, J. A., “Surface Modification of Titanium by Atmospheric Pressure Plasma for Adhesive Bonding and its Application to Aviation and Space”, in Euromat: 2009 European Congress and Exhibition on Advanced Materials and Processes, Glasgow, UK, 2009.

2009

Conference Paper

R. Benedictus, Shantanu Bhowmik, Poulis, J. A., and Akram, M., “Surface Modification of Polyimide by Atmospheric Pressure Plasma for Adhesive Bonding with Titanium and its Application to Aviation and Space”, in Sixth International Symposium on Polyimides and other High Temperature/High Performance Polymers Synthesis, Characterization And Applications, Florida Institute of Technology, Melbourne, FL, USA, 2009.

2009

Conference Paper

R. Benedictus, Faraz, M. I., and Shantanu Bhowmik, “Synthesis of High Temperature Bismaleimide /Carbonnanofibers Nanocmposites by Thermokinetic Mixing”, in American Society for Composites - 24th Technical Conference, University of Delaware ,USA, 2009.[Abstract]


Polymeric nanocomposites have received immense attention in the recent years. This is because of remarkable improvement in all area at very low filler level as compared to macrocomposites.High temperature composites are a great deal of interest for aerospace industry which is the largest beneficiary of composites development. Thermosetting resins are mostly used in composite manufacturing dominated by epoxy at the moment.Polyimides are also now in use but still limited due to high temperature and pressure processing and cost limitation. Bismaleimide is a high temperature thermoset having stability at elevated temperature, low volatiles, high strength and low shrinkage as compared to epoxy .Carbon nanotubes (CNTs) have demonstrated remarkable mechanical, thermal and electrical properties, showing as promising filler for high performance polymer matrix. Dispersion of CNTs is a great problem to be addressed yet and technology is still evolving. In this study carbon nanofibers (CNFs) are used with a novel high temperature bismaleimide in order to make a high temperature nanocomposite.A high quality thermokinetic mixing device, gelimat blender is udsed.Two concentrations of CNFs 1-2wt%are taken for this study. The dispersion is characterized by SEM and TEM which shows a uniform dispersion of the CNFs overall. Thermal analysis is carried out by TGA, and DMTA. An increase in thermal decomposition and glass transition temperature is observed. Mechanical strength has shown reverse effect.

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2009

Conference Paper

S. Choudhury, Kumar, A., Bui, V. T., Bonin, H. W., Shantanu Bhowmik, and Ayan, D., “Digitally Controlled Preparation, Characterization and Adhesion Properties of carbon Nanotube Based Epoxy Nano Composites”, in SWISSBONDING 09: 25th International Congress of Adhesion and Bonding Technology, Lake of Zurich , 2009.

2008

Conference Paper

S. - O. Park, Moon, J. - B., Lee, Y. - G., Kim, C. - G., and Shantanu Bhowmik, “Usage of fiber Bragg grating sensors in low earth orbit environment”, in The 15th International Symposium on: Smart Structures and Materials & Nondestructive Evaluation and Health Monitoring, San Diego, 2008.[Abstract]


It is widely known that materials exposed to the severe low earth orbit (LEO) environment undergo degradations. For the evaluation of fiber Bragg grating (FBG) sensors in the LEO environment, the reflective spectrum change and the Bragg wavelength shift of FBG sensor were measured during aging cycles simulating the LEO environment. The LEO environment was simulated by high vacuum (~10-5 Torr), ultraviolet (UV) radiation (<200nm wavelength), temperature cycling (-30°C~100°C), and atomic oxygen atmosphere (AO flux of 9.12×1014 atoms/cm2/s and kinetic energy of ~0.04 eV). FBG sensor arrays were embedded into the graphite/epoxy composite material. Through the aging cycles simulated for the LEO environment, the change in the reflective spectrums and the Bragg wavelengths from FBG sensors were investigated.

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2008

Conference Paper

Shantanu Bhowmik, Kim, C. J., and Benedictus, R., “Space Radiation at Geosynchronous Earth Orbit and Scope of Space Durable Polymeric Nano Composite”, in International Conference on Rubber and Rubber like Materials, Rubber Technology Centre, IIT Kharagpur, 2008.

2008

Conference Paper

R. Benedictus, Poulis, J. A., and Shantanu Bhowmik, “Fabrication of Aluminium by High Performance Nano Adhesive for Aerospace and Space Applications”, in 5th International Conference on Thin Walled Structures , Brisbane, Australia, 2008.

2008

Conference Paper

Shantanu Bhowmik and Benedictus, R., “Comparative Studies and Failure Mechanism of Ceramic Adhesive and Organic Adhesive for Fabrication of Polymer to Metal”, in 1st Indo -SwissBONDING International Conference, Madras Institute of Technology, Anna University, Chennai, 2008.

2008

Conference Paper

Shantanu Bhowmik and Benedictus, R., “Application of Polymeric Nano Composite at Low Earth Orbit”, in 13th European Conference on Composite Materials , Stockholm, Sweden, 2008.

2008

Conference Paper

Shantanu Bhowmik and Benedictus, R., “Space Radiation at Geosynchronous Earth Orbit and Performance of Different Space Durable Polymeric Nano Composites”, in Asian Polymer Association Conference of Indian Institute of Technology, 2008.

2008

Conference Paper

R. Benedictus, Patel, V. K., Chaki, T. K., Shantanu Bhowmik, and Poulis, J. A., “Developments in Plasma Assiated Surface Treatments of Aluminium and its Alloys for Adhesive Bonding”, in 1st Indo-SWISSBONDING International Conference, Madras Institute of Technology, Anna University, Chennai, 2008.[Abstract]


Presently, many industrial sectors including aerospace industry, there is a significant use of aluminium as light weight materials which eventually results cost savings and low fuel consumption. Alluminium and alluminium alloys have high specific strength, good machinability, formability and corrosion resistance but exhibits poor adhesion properties due to complex surface properties. Very often aluminium is fabricated for desired structure by adhesive bonding rather that welding, riveting or brazing. In this context, pre-treatment of alluminium alloys prior to adhesive bonding or painting is a very important factor. However, use of traditional wet chemical methods of pretreatments shows ecological challenges and therefore, there is a clear interest in ecologically cleaner vacuum-based plasma technology. The plasma deposition of thin film coatings on alluminium that exhibit strong interfacial bonding could provide an alternative to the traditional chromate-based treatments. The plasma deposited coatings confer protection against corrosion and provide a good interface for strong, durable adhesive bonds. The 2024 alluminium alloy structure of an aircraft or a helicopter is commonly protected from severe conditions and heavy stresses by a paint coating. Cold plasma represents an efficient, non polluting and economical alternative to clean, activate and, then, to increase the adhesive properties of alluminium surfaces. Therefore, cold plasma reduces the amount of primer needed to be applied and the weight of whole structure. In addition to that the adhesive bonding of composite patch to repair cracks in metallic structures is an accepted technology in aerospace and automobile industries. The bond strength between composite patch and metallic structure is significantly affected by the surface preparation of the composite patch and metallic structure. The surface treatment effect of alluminium by plasma on the bond strength of alluminium/CFRP composites exhibits 33% higher shear strength and 6 times higher T-peel strength than those of untreated allluminium/CFRP composites. The optimal plasma treatment time and the ratio of acetylene gas to nitrogen gas are found to be 30 sec and 5:5 respectively. The surface treatment effect of alluminium foam and alluminium by plasma on the bond strength of alluminium foam/ alluminium composites exhibit 13% higher bending strength and 30% higher shear strength compared to no plasma treatment. However, plasma treatment of alluminium foam produces a similar result to the case with no plasma treatment on alluminium. In this context, resent developments on Plasma electrolytic oxidation (PEO) process is also an important technology to incorporate oxide layers on alluminium alloys with high tribological properties. PEO results a smaller reduction in fatigue strength of 7475-T6 alluminium alloys and a substantial reduction in the case of hard anodizing. The better fatigue performance of the PEO coatings are attributed to the developments of compressive residual stress within the coatings. In order to activate aluminium surface, another important technology is plasma nitriding, by using nitrogen as process gas. Prior to nitriding, the aluminium surfaces are cleaned by plasma-assisted sputtering process resulting in significant improvement of adhesive bond strength of aluminium leading to improvement in durability at aerospace service conditions.

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2007

Conference Paper

Shantanu Bhowmik, Benedictus, R., and Poulis, J., “Fabrication of Space Durable Polymer and its Performance under Space Environments”, in 45th American Institute of Aeronautics and Astronautics (AIAA) Aerospace Sciences Meeting and Exhibition, Reno Hilton, Reno, Nevada, USA. , 2007.

2007

Conference Paper

Shantanu Bhowmik, Benedictus, R., and Poulis, H., “Influence of space radiation on nano adhesive bonding of high performance polymer”, in International Conference on Polymers in Defence and Aerospace, Toulouse, France, 2007.

2007

Conference Paper

Shantanu Bhowmik and Benedictus, R., “Performance of space durable polymeric nano composite under electromagnetic radiation at Low Earth Orbit”, in Applied Electromagnetics Conference, 2007. AEMC 2007. IEEE, Kolkata, India, 2007.[Abstract]


It is well known that during long mission at low Earth orbit (LEO) as well as geosynchronous Earth orbit (GEO), electromagnetic radiation such as proton, gamma rays, alpha particles etc. creates severe damages to space electronics equipment as well as structural materials of spacecraft. In this context, present study investigates the rationale to developing space materials which could be useful as shielding material for spacecraft when spacecraft is subject to intense radiation at low Earth orbit (LEO). It is noted that several international space agencies such as National Aeronautics and Space Administration (NASA), European Space Agency (ESA) have launched several programs to investigating materials and techniques for shielding of spacecraft structure as well as electronic equipments involved in long-term missions. Usually high-mass density materials of high atomic number, are not good choices for shielding the spacecraft because, when struck by the primary positive ions, the nuclei of these materials fragment and produce a shower of secondary radiation that includes more charged particles, photons, and neutrons, and the thicknesses of heavy shielding material necessary to stop these becomes excessive from a weight standpoint. Therefore, new shielding materials that not only block and/or fragment more radiation than aluminium - the material currently used to build most spacecraft structures but also lighter than aluminium is polyethylene which is a good shielding material because it has high hydrogen content and hydrogen atoms are good at absorbing and dispersing radiation. However, longer mission under electromagnetic radiation, mechanical properties of the polymer deteriorate. Therefore, one of several novel material developments that are currently being researched is nano reinforced polyethylene and proper selection of nano particles in terms of physicothermal and theromechanical properties are of priorities. It is proved that at longer mission at LEO, polyethy- - lene based shielding materials are not so useful in terms of physicothermal and thermomechanical properties. Therefore, attention is given to find better shielding materials and one such material is space durable polymer such as polybenzimidazole (PBI) having higher service temperature and also having excellent properties to resist high energy radiation. Therefore, this paper highlights future of polymeric nano composite based on these polymers with dispersion of appropriate nano particles such as carbon nano fibre and calcium and that could be a solution for materials of space radiation shielding for long mission at LEO.

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2007

Conference Paper

Shantanu Bhowmik, Benedictus, R., and Poulis, J. A., “Fabrication of Nano Adhesive Bonding of Titanium for Aerospace Applications”, in 11th World Conference on Titanium, International Conference Hall in Kyoto, Japan, 2007.

2007

Conference Paper

R. Benedictus, Bui, V. T., Weir, R. D., Bonin, H. W., and Shantanu Bhowmik, “Modification of Single Walled Carbon Fibre Nano Tube Dispersed High Performance Adhesive Bonding of Titanium”, in SWISSBONDING 07: 21st International Congress of Adhesion and Bonding Technology, , Lake of Zurich, Switzerland, 2007.

2007

Conference Paper

C. J. Kim, Shantanu Bhowmik, and Benedictus, R., “Development of High Performance Polymeric Nano Composite for Space Radiation Shielding”, in Interdisciplinary Transport Phenomena V: Fluid, Thermal, Biological, Materials and Space Sciences, Bansko, Bulgaria, 2007.

2006

Conference Paper

Shantanu Bhowmik, Bonin, H. W., Bui, V. T., and Benedictus, R., “Nano Adhesive Bonding of High Performance Polymer for Aerospace Applications”, in 8th International Conference on Flow Processes in Composite Materials (FPCM8), Ecole des Mines de Douai, Douai, France, 2006.[Abstract]


In this investigation, attempts are made to prepare nano adhesive bonding of high performance polymer such as Polybenzimidazole (PBI) (service temperature is –260<sup>0</sup> C to +400<sup>0</sup> C) for its essential applications to aerospace. In order to prepare high performance adhesive, nano adhesive is prepared by dispersing silicate nano particles into the ultra high temperature resistant epoxy adhesive (DURALCO 4703, the service temperature of the adhesive is –260<sup>0 </sup>C to +325<sup>0</sup> C) at 10% weight ratio with the matrix adhesive followed by modification of the nano adhesive after curing under high-energy radiation for 6 hours in the pool of SLOWPOKE-2 nuclear reactor with a dose rate of 37 kGy/hr in order to essentially increase the crosslink density within the nano adhesive resulting in much improved cohesive properties of the adhesive. Prior to bonding, the surface of the Polybenzimidazole is ultrasonically cleaned by acetone followed by its modification under low-pressure plasma using nitrogen as process gas under RF glow discharge, in order to essentially increase the surface energy of the polymer leading to substantial improvement of its adhesion characteristics. First, the polymer surfaces are characterized by estimating surface energy and then the polymer surface is characterized by Electron Spectroscopy for Chemical Analysis (ESCA). The thermal characteristics of the basic ultra high temperature resistant epoxy adhesive and the high performance ultra high temperature resistant radiation cross linked silicate nano adhesive are carried out by TGA and DSC and the physicochemical characteristics of these adhesives are carried out by the studies under solid state NMR. The TGA studies clearly shows that for the basic adhesive, there is a weight loss of the adhesive of about 10% when the adhesive is heated up to 325<sup>0</sup> C resulting in deterioration of cohesive properties of the adhesive over the range of temperatures. However, in the case of the radiation cross linked epoxy-silicate nano adhesive, there is a perfect 100% retention of weight of the adhesive when the adhesive is heated up to 325<sup>0</sup> C resulting in significant improvement of cohesive properties of the adhesive over the range of temperatures. In order to determine the joint strength, tensile lap shear tests are performed according to ASTM D 5868-95 standard. Considerable increase in the joint strength is observed, more than 15 times when the polymer surface is modified prior to joining. Joints prepared with the unmodified polymer show only a joint strength of 1 MPa and increases up to 15.50 MPa with the surface modified polymer. There is a further massive increase in joint strength up to 25 MPa, when the joint is prepared by nano silicate epoxy adhesive and further modification of the adhesive joint under high-energy radiation results a further significant increase in joint strength up to 30 MPa. Therefore, with all the combinations there is about 30 times increase in joint strength. In order to simulate with aerospace climatic conditions, the joints are exposed to cryogenic (-80<sup>0</sup> C) and elevated temperature (+300<sup>0</sup> C) for 100 hours and further, thermal fatigue tests of the joints are carried out under 10 cycles by exposing the joint for 2 hours under the above temperatures. When the joint completely kept at ambient condition and the joint strength compared with those joints exposed to aerospace climatic conditions, it is observed that there is no difference in joint strength. Finally, to understand the behavior of high performance silicate epoxy nano adhesive bonding, the fractured surfaces of the joints are examined by scanning electron microscope. It is observed that the joint essentially fails cohesively within the adhesive even when the joints are exposed to cryogenic, elevated temperature and thermal fatigue conditions. Therefore, this nano adhesive bonding of high performance polymer could be highly useful for structural application in future generation aerospace.

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2006

Conference Paper

J. A. Poulis, Shantanu Bhowmik, Benedictus, R., Bonin, H. W., Bui, V. T., and Weir, R. D., “Space Durable Polymeric Composite Modified by Low Pressure Plasma and High Energy Radiation and its Performance under Space Environments”, in 7th International Symposium on Ionizing Radiation and Polymers, Antalya, Turkey, 2006.[Abstract]


In this investigation, attempts are made to modify space durable polymer such as polybenzimidazole (PBI) (service temperature ranges from -260 °C to +400 °C, and also exhibits extreme fire and high energy radiation resistance) through low-pressure plasma inorder to prepare composite with the same polymer. The Polybenzimidazole composites are prepared using an ultra high temperature resistant epoxy adhesive in order to join the two polymer sheets. The service temperature of this adhesive ranges from -260 °C to +370 °C and, in addition, this adhesive has excellent resistance to most acids, alkalis, solvents, corrosive agents, radiation and fire, making it extremely useful for space applications. Prior to preparing the composite, the surface of the polybenzimidazole is ultrasonically cleaned by acetone followed by its modification through low-pressure plasma through 13.56 MHz RF Glow Discharge for 30, 60, 120, 240 and 360 seconds at 100 W of power using nitrogen as process gas. Prior to adhesive bonding, the polymer surfaces are characterized by estimating surface energy and Electron Spectroscopy for Chemical Analysis (ESCA). It is observed that polar component of surface energy leading to total surface energy of the polymer increases significantly up t o 120 seconds of exposure and then it saturates. In order to determine the joint strength, tensile lap shear tests are performed according to ASTM D 5868-95 standard. It is observed that joint strength increases significantly with increasing exposure of low pressure plasma up to 120 seconds followed by its saturation. Another set of experiments is carried out by exposing the low-pressure plasma modified polymer joint, under the SLOWPOKE-2 safe low power critical experiment) nuclear reactor for 6 hours, which produces a mixed field of thermal and epithermal neutrons, energetic electrons and protons, and gamma rays, with a dose rate of 37 kGy/hr. It is observed that there is further significant increase in joint strength, when the polymer surface is first modified by low-pressure plasma of 120 sec of exposure followed by exposing the joint under high-energy radiation. In order to simulate with spatial conditions, the joints are exposed to cryogenic (-196 °C) and elevated temperature (+300 °C) for 100 hours. Then tensile lap shear tests are carried out in order to determine the effects of these environments on the joint strength. It is observed that when these polymeric joints are exposed to these climatic conditions, the joints could retain their strength of about 95% of that of joints tested under ambient conditions. Finally, in order to understand the failure modes of the joint, the fractured surfaces of the joints are examined by scanning electron microscope. It is observed that unmodified polymer-to-polymer joint fails completely through the interface; whereas the surface modified polymer essentially fails cohesively within the adhesive resulting in significant increase in joint strength. Therefore, this space durable polymeric composite could be highly useful for structural applications in spacecraft.

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2006

Conference Paper

V. T. Bui, Bonin, H. W., Weir, R. D., and Shantanu Bhowmik, “High Performance Nano Adhesive Bonding of High Temperature Resistant Polymer to Titanium for Aviation and Space Applications (Invited Author)”, in SWISSBONDING 06: 20th International Congress of Adhesion and Bonding Technology, Lake of Zurich, Switzerland, 2006.

2005

Conference Paper

V. T. Bui, Weir, R. D., Bonin, H. W., and Shantanu Bhowmik, “Adhesion and Durability of High Performance Polymer under Space and Radiation Environments (Invited Author)”, in SWISSBONDING 05: 19th International Congress of Adhesion and Bonding Technology, Lake of Zurich, Switzerland , 2005.

2005

Conference Paper

Shantanu Bhowmik, Weir, R. D., Bonin, H. W., and Bui, V. T., “Thermal Fatigue Behavior of Adhesive Bonding of Titanium for Aerospace Application (Invited Author)”, in SWISSBONDING 05: 19th International Congress of Adhesion and Bonding Technology, Lake of Zurich, Switzerland, 2005.

2005

Conference Paper

H. W. Bonin, Shantanu Bhowmik, and Bui, V. Tam, “Effect of Space and Radiation Environments on Durability of High Performance Polymer to Titanium Adhesive Joints”, in The Fifth Canadian International Composites Conference CANCOM 2005, Vancouver, Canada , 2005.

2004

Conference Paper

T. K. Chaki, Bui, V. T., Bonin, H. W., and Shantanu Bhowmik, “Influence of Different Electrodes of Low Pressure Plasma on Physicochemical and Adhesion Characteristics of High Density Poly Ethylene”, in 7th International Conference in Structural Adhesives in Engineering, Bristol, UK , 2004.

2004

Conference Paper

V. T. Bui, Bonin, H. W., Wier, R. D., and Shantanu Bhowmik, “Effects of High Energy Radiation on Adhesive Bonding of Titanium for Nuclear and Space Application”, in 7th International Conference in Structural Adhesives in Engineering, Bristol, UK , 2004.

2003

Conference Paper

Shantanu Bhowmik and Chaki, T. K., “Failure Analysis of Adhesive Joint of DC Glow Discharge Exposed PP to Steel”, in Fourth International Symposium on Polymer Surface Modification: Relevance to Adhesion, Novotel, Toronto Centre, Toronto, Canada, 2003.[Abstract]


The present investigation aims to analyze the failure mechanism of adhesive joint of DC glow discharge exposed PP to mild steel for attaining best adhesive joint of PP to mild steel. The as received and DC glow discharge exposed PP surfaces have been characterised by Energy Dispersive Spectra (EDS). Lap shear tensile tests have been carried out for the unexposed polymer and those exposed under DC glow discharge (i) at different power levels and (ii) for different duration of exposure. It is observed that with increasing power level lap shear tensile strength of adhesive (Araldite AY 105) joint of PP to mild steel increases till 13 W of power level, beyond which the joint strength decreases. Further, at this power level the joint strength increases with increasing exposure time upto 120 s and then joint strength decreases. At the optimized condition for the surface modification the effect of using another adhesive (Araldite 2011) on the strength of the joint has also been determined. The fractured surfaces of the specimens tested under lap shear tensile test have been examined in order to analyse the failure mechanism of the polymer to mild steel adhesive joints so that the best adhesive joint can be made. In addition, the polymer to polymer and mild steel to mild steel joints using these adhesives have also been examined. The fracture surface has been analyzed by optical microscopy and Energy Dispersive Spectra (EDS). The fracture surfaces of these joints studied under optical microscopy and Energy Dispersive Spectra (EDS), show that when unexposed polymer is joined with mild steel, the failure is confined to polymer to adhesive interface. However, when the polymer, has been modified by exposure under glow discharge the failure mode is changed. The failure is observed throughout subsurface layer of the PP. From the strength analysis of adhesive joint of either glow discharge exposed PP to mild steel, or glow discharge exposed PP to PP, it is observed that joint strength does not change with the change of adhesive and this could be possible as failure takes place throughout the subsurface layer of the PP.

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2003

Conference Paper

Shantanu Bhowmik and Chaki, T. K., “Wetting and Adhesion Characteristics of DC and RF Glow Discharge Exposed PP”, in Fourth International Symposium on Polymer Surface Modification: Relevance to Adhesion, Novotel, Toronto Centre, Toronto, Canada, 2003.[Abstract]


The present investigation aims to optimise the process parameters of DC and RF glow discharge treatment through air in terms of discharge power and time of exposure for the surface modification of PP sheet, for attaining best adhesive joint of the polymer to mild steel. In order to estimate the extent of surface modification, the surface energies of the polymer surfaces exposed to glow discharge have been determined by measuring contact angles using two standard test liquids of known surface energies. It is observed that at a given power level of DC glow discharge, surface energy and its polar component increases with increasing exposure time which attains maximum and then decreases. In the case of RF glow discharge, surface energy and its polar component increases with increasing exposure time and then saturate before reaching to maximum level. Surface modification by DC glow discharge increases the surface energy of PP relatively more at a lower power compared to that observed for RF glow discharge. The dispersion component of surface energy remains almost unaffected. The surfaces have also been studied by Electron Spectroscopy for Chemical Analysis (ESCA) and Energy Dispersive Spectra (EDS). Significant oxygen peak is observed for surface modified polymer as detected by ESCA and EDS. Lap shear tensile test of adhesive (Araldite AY 105) joint of PP with mild steel has been carried out in optimising the parameters of DC and RF glow discharge for maximum joint strength. When PP is exposed to DC glow discharge, improvement of adhesive joint strength of PP to mild steel is found to be by a factor nearer to 6. On the otherhand, when PP is exposed to RF glow discharge, results in improvement of adhesive joint strength of PP to mild steel by a factor lower than 5 is found. Thus, DC glow discharge is more capable for increasing wetting and adhesion characteristics of the polymer.

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2003

Conference Paper

Shantanu Bhowmik, Chaki, T. K., and Ray, S., “Surface Modification of HDPE and PP by Low Pressure Plasma and Adhesive Joining to Steel”, in India Rubber Expo, Mumbai, India, 2003.

2001

Conference Paper

Shantanu Bhowmik, Ghosh, P. K., Ray, S., Hoffman, F., and Dorn, L., “Surface Modification of HDPE and PP under DC and RF Glow Discharge for Adhesive Joining to Steel”, in National Seminar on Advances in Materials and Processing, Indian Institute of Technology, Roorkee, 2001.

2000

Conference Paper

P. K. Ghosh, Ray, S., and Shantanu Bhowmik, “Effect of Surface Modification and Surface Chemistry of Glow Discharge treated HDPE and PP on the Strength of their Adhesive Joint to Steel”, in International Seminar on Polymer Materials in 21 st Century, New Delhi, India. , 2000.

1999

Conference Paper

S. Ray, Ghosh, P. K., and Shantanu Bhowmik, “Effect of Mechanical Polishing on the Surface Modification of HDPE and PP by DC Glow Discharge and their Adhesive Joining to Steel”, in International Symposium on Polymer Surface Modification: Relevance to Adhesion, Newark, NJ, USA., 1999.

Publication Type: Book Chapter

Year of Publication Publication Type Title

2014

Book Chapter

Shantanu Bhowmik, Benedictus, R., and Dan, Y., “Adhesive Bonding Technology”, in Handbook of Manufacturing Engineering and Technology, Springer, 2014, pp. 765–784.[Abstract]


The chapter gives a brief introduction of adhesive bonding technology. Emphasis is placed on understanding of the fundamental mechanisms of bonding. Various types of adhesives are compared, and the techniques to modify polymer surface for improving the adhesion strength are described in detail. Examples are given to show important applications of adhesive bonding technology in automotive and aerospace industries.

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2012

Book Chapter

H. M. S. Iqbal, Shantanu Bhowmik, Bhatnagar, N., Mondal, S., and Ahmed, S., “High Performance Adhesive Bonding of High Temperature Resistant Polymer”, in Journal of Adhesion Science and Technology, vol. 26, Taylor & Francis, 2012, pp. 955–967.[Abstract]


This paper highlights effects of atmospheric pressure plasma treatment on adhesive joints of poly (ether ether ketone) (PEEK) fabricated with high temperature resistant epoxy adhesive and nano-adhesive, i.e., by dispersing carbon nanofibers (CNFs) into the adhesive matrix. Thermogravimetric analysis (TGA) demonstrates that there is an increase in thermal stability up to 15% for nano-adhesive. Substantial improvement in the surface energy of PEEK is observed after the atmospheric pressure plasma treatment. It is observed that polar component of surface energy leading to higher total surface energy of PEEK increases considerably. Atomic force microscopic (AFM) analysis of untreated and atmospheric plasma treated specimens was carried out to examine topography of the polymer surfaces. After atmospheric plasma treatment, surface roughness of the polymer increases which helps in improving the adhesion properties of thepolymer. Atmospheric pressure plasma treatment results in significant increase in oxygen functionalities as detected by X-ray photoelectron spectroscopy (XPS). The improvement inadhesion properties of polymer is correlated with lap shear strength of adhesive bonded joints.Adhesive bonded joints were fabricated by employing recently developed ultrahigh temperatureresistant epoxy adhesive, DURALCO 4703. Lap shear test results show that adhesioncharacteristic of PEEK improves considerably after atmospheric plasma treatment. Finally, the fractured surfaces of the joints were examined by scanning electron microscopy to investigate the failure mechanism.

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2011

Book Chapter

Shantanu Bhowmik, “Effect of Radiation and Vacuum”, in Handbook of Adhesion Technology, Springer, 2011, pp. 823–844.[Abstract]


This chapter describes basic understanding of high-energy radiation as well as space vacuum and properties of high-performance polymers and adhesives when exposed to high-energy radiation in vacuum. Therefore, different radiation conditions are analyzed, and stability of different polymers under radiation and vacuum are described. As a case study, performance of space durable polymer such as polybenzimidazole (PBI) modified by low-pressure plasma and atmospheric-pressure plasma and fabrication of the polymer by ultrahigh temperature-resistant epoxy adhesive (DURALCO 4703) is reported. The service temperature of this particular adhesive ranges from −260°C to +350°C, and in addition this adhesive has excellent resistance to most acids, alkalis, solvents, corrosive agents, radiation, and fire, making it extremely useful when subject to space radiation. Prior to fabrication of PBI, the surface of PBI is ultrasonically cleaned by acetone followed by its modification through low-pressure plasma with 30, 60, 120, 240, and 480 s of exposure. Surface characterization of the unmodified and modified PBI sheets is carried out by contact-angle measurements by which surface energy is calculated. It is observed that polar component of surface energy leading to total surface energy of the polymer increases significantly when exposed to low-pressure plasma. X-ray Photoelectron Spectroscopy (XPS) reveals that the polymer surface becomes hydrophilic, resulting in increase in surface energy. High-energy radiation related to outer space is simulated with mixed-field radiation generated by SLOWPOKE-2 (safe low power critical experiment) nuclear reactor. Therefore, in order to see the performance of the adhesive joint of PBI under outer-space radiation, the joint is exposed to SLOWPOKE-2 nuclear reactor up to a dose of 444 kGy and critically analyzed.

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Publication Type: Conference Proceedings

Year of Publication Publication Type Title

2012

Conference Proceedings

M. Akram, Jansen, K. M. B., Shantanu Bhowmik, and J, E. Leo, “Durability of Polyimide to TitaniumBonds”, 15th European Conference on Composite Materials. Venice, Italy , 2012.

2011

Conference Proceedings

M. Akram, Jansen, K. M. B., Shantanu Bhowmik, and Ernst, L. J., “MOISTURE ABSORPTION ANALYSIS OF HIGH PERFORMANCE POLYIMIDE ADHESIVE”, Proceedings of SAMPE Fall Technical Conference. Port Worth, Texas, USA, pp. 1-9, 2011.[Abstract]


The high temperature resistant polymers and metal composites are used widely in aviation, space, automotive and electronics industry. The high temperature resistant polymers and metals are joined together using high temperature adhesives. Polyimide and epoxy adhesives that can
withstand high temperature (200 °C-300 °C) are commonly used for joining high temperature metals and polymers. The performance of adhesively bonded metals and polymers depends upon physical properties of these high temperature adhesives. The physical properties like modulus,
Tg. coefficient of thermal expansion (CTE) etc., are affected by external factors such as force, temperature, humidity etc. The external factors play a vital role in the adhesive bond strength and the durability of bond between metal and polymer. In this investigation moisture absorption
analysis of polyimide adhesive is performed using Q5000 moisture absorption analyzer. The moisture absorption data of polyimide at different temperatures and humidity level is obtained. Further, the moisture absorption data is fitted to well known Fickian-fit model to determine the
diffusion coefficient (D) and saturated moisture gain Msat. Diffusion coefficient (D) and Msat of polyimide and epoxy adhesive are calculated at different temperature and different humidity level. It is observed that diffusion coefficient changes with the change in temperature and
humidity level. The diffusion coefficient (D) and M sat data are used in Fick’s second law of diffusion to estimate the time needed for preconditioning of the adhesively bonded titanium samples in humidity chamber at elevated temperature and higher moisture level. After preconditioning of adhesively bonded Titanium samples in moisture chamber for estimated time, samples will be subjected to lap shear tensile test to study the effect of these elevated conditions on adhesive bond strength.

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2009

Conference Proceedings

H. M. S. Iqbal, Shantanu Bhowmik, and Benedictus, R., “Thermo-mechanical Characteristics of Space Durable Nano Adhesive Joint of High Performance Polymer”, 50th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference. Palm Springs, California, USA, 2009.[Abstract]


In recent times, considerable efforts are given through out the world for the development of composite materials lighter in weight as well as with superior thermomechanical properties. These materials can withstand a temperature in excess of +300°C for longer time or much higher temperatures for short time. Due to excellent thermal, physical and mechanical properties, polybenzimidazol (PBI) is considered to be one of the leading candidates for aerospace and space applications. Polymers and composite materials are often fabricated by adhesive bonding to form structural components. Therefore, in this investigation; PBI, carbon fiber reinforced and glass fibers reinforced polyphenylene sulfide (PPS) composites are fabricated by employing recently developed ultrahigh temperature resistant epoxy adhesive, DURALCO 4703 (service temperature -250 0C to +350 0C). Prior to fabrication, the polymer surfaces are modified by atmospheric pressure plasma in order to increase their surface energy leading to improving adhesion. Lap shear tensile test is carried out to evaluate the adhesion characteristics of the polymers. Three to four times increase in the lap shear strength is observed for PPS-CF and PPS-GF composite joints after plasma treatment when compared with untreated composite joints. Carbon nanofibers (CNFs) are added to enhance the mechanical and physical properties of adhesive. Addition of 1% CNFs to epoxy adhesive has increased the thermal stability of the adhesive up to 15% when compared to basic adhesive. Lap shear strength of nano-adhesive using PPS-GF composite is increased up to 20%. No real increase in lap shear strength of nano-adhesive is observed with PPS-CF composite. Optical microscopic analysis of untreated and plasma treated is carried out to analyze the surface. After plasma treatment, enlarged peaks are observed on the surface which helps in improving the adhesion. Finally, the fractured surfaces of the joints are examined by scanning electron microscope.

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2009

Conference Proceedings

H. M. S. Iqbal, Faraz, M. I., Shantanu Bhowmik, and Benedictus, R., “Microgravity Fire at Low and Geosynchronous Earth Orbit and Scope of Space Durable Polymeric Nano Composites”, Proceedings 7th International conference on composite science and technology. Sharjah, UAE, 2009.

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