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.
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.
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.