Course Title: 
Interfacial Science and Engineering
Course Code: 
Year Taught: 
Undergraduate (UG)
School of Engineering

'Interfacial Science and Engineering' is an elective course offered in the B. Tech. in Chemical Engineering program at School of Engineering, Amrita Vishwa Vidyapeetham, Coimbatore.

Unit 1

Introduction – colloids, surfaces and interfaces, Colloids - classifications and characterizations. Colloids - preparation and purification methods - Surfaces and interfaces – definitions, description of different surface and interfaces, applications of interfacial engineering - Surface, interfacial tensions and measurement of interfacial tension using different methods - Surface properties.

Attractive forces and van der Waals interactions - Columbic forces and ionic, dipole interactions. Van der Waals forces in polar and non-polar media - Electrostatic and Electrokinetic theories.

Source of interfacial formation and electrical double layer (EDL) - Helmholtz model, Gouy-Chapmanmodel, Debye–Hückel theory on EDL, EDL thickness - Surface potential, Zeta potential, pH effects, calculations - Electroosmosis and Electrophoresis, types, applications.

Unit 2

Capillary theories, Capillary driving forces in liquid–fluid systems, Solid–Liquid– Fluid Systems: The Effect of Contact Angle - Capillary Flow and Spreading Processes, coefficients, petroleum recovery, measurement of capillary driving forces - Surface tension gradients, marangoni flow, contact angle hysteresis, dynamic contact angles, Practical capillary systems – wetting in fibers, water proofing, wicking process and detergency.

Adsorption – Gibbs surface excess, adsorption equation for Solid-Fluid interfaces, Gibbs adsorption isotherm – Physisorptionvs Chemisorption, Thermodynamic considerations, heterogeneous catalysis.

Catalytic poisons, promoters and adsorption isotherms at S-V interfaces, Langmuir, Freundlich, BET adsorption isotherms and surface area calculations, adsorption at S-L interfaces - Adsorption isotherms in solid–liquid systems, nature of the adsorbent surface, environmental effects - Colloidal stability – Coagulation, flocculation, mechanism for colloidal formation.

Unit 3

Colloidal behaviour, Lennard–Jones 6–12 potential, attractive forces, sources of colloidal stability, critical coagulation concentration -Coagulation kinetics - fast and slow, Smoluchowski equation, DLVO theory, reversible flocculation.

Emulsions - formation, emulsification methods-Emulsifiers and Stabilizing agents, types, functions.

HLB number, PIT and Application of HLB and PIT in Emulsion Formulation - Association colloids - vesicles, micelles and membranes -Surfactant solubility, krafft temperature, and cloud point - Surfactant liquid crystals, micelles, micelle formation - Critical micelle concentrations (CMC) - factors affecting CMC, additives - Vesicles and bilayer membranes – definitions, applications.

Optical properties - Light scattering, turbidity, light scattering theories - Scattering by small particles, large particles, Rayleigh, Debye and Mie scattering of particles - Foams, Aerosols, Foam stability and microfoams - Rheological properties of colloidal dispersions - viscosity, newtonian and non-newtonian fluids, Electroviscous effects.

  • Drew Myers, Surfaces, Interfaces, and Colloids: Principles and Applications. 2nd Ed., Wiley-VCH, 1999
  • D. J. Shaw, Colloid & Surface Chemistry, 4th Edition, Butterworth-Hienemann, 2003,
  • Intermolecular and Surface Forces, Jacob N. Israelachvili, Academic Press, 1992