Emulsions, Microemulsions and Foams

1. Common background (about 100 pages) 1.1 Interfaces between pure fluids
┬╖ Surface tension, Contact angle, wetting
┬╖ Interface thickness: intrinsic profile, thermal fluctuations
1.2. Irreversibly adsorbed surface-active species
┬╖ Surface pressure, surface rheology (compression and shear, viscoelasticity)
┬╖ Polymer layers: thickness, rheology, case of proteins
┬╖ Other species: asphaltenes, particles
┬╖ Mixed layers

1.3. Surfactant layers
┬╖ Adsorption-desorption: Gibbs description, validity of the Gibbs equation, Langmuir equation of state, energy barriers, depletion.
┬╖ Non-equilibrium systems: sorption and transfer kinetics, "dynamic" tension
┬╖ Surface rheology: extension of Gibbs description, resistance to compression and shear, viscoelasticity, Levich model, influence of the surface charge

1.4 Thin films: Interaction between surfaces (van der Waals, electrostatic, short range), disjoining pressure. Oscillatory forces, film stratification

1.5 Surfactants and self-associated systems: micelles, lyotropic liquid crystals,
┬╖ Surfactant parameter, link with HLB, HLD and PIT
┬╖ Critical micellar concentration, link with surfactant solubility, exchanges with bulk
┬╖ Micelle size distribution, micelles in organic solvents
┬╖ Lyotropic liquid crystalline phases, phase diagrams, dispersed phases (cubosomes, hexosomes)

2. Microemulsions (about 40 pages) 2.1 Thermodynamic stability
┬╖ Structure, role of the spontaneous curvature and of the curvature elasticity of the surfactant layer
┬╖ Percolation
┬╖ Exchanges, shape fluctuations

2.2 Phase diagrams
┬╖ Emulsification failure and other solubility limits
┬╖ "Fish" diagrams, critical points

2.3 Bicontinous microemulsions
┬╖ persistence length of the surface layer
┬╖ transition to lamellar phases or to molecularly dispersed phases

2.4 Ultralow interfacial tensions: origin, wetting phenomena

3. Emulsions and foams (about 130 pages) 3.1 Emulsion and foam structures, analogies between high internal phase emulsions (HIPE) and foams, monodisperse dispersions

3.2 Foaming and emulsification: methods, control of drop/bubble size

3.3 Foam and emulsion rheology
┬╖ Wall slip
┬╖ Soft solid behavior, rejuvenation
┬╖ Link with structural reorganisation processes, the jamming transition
┬╖ Role of interfacial rheology

3.4 Foam and emulsion stability
┬╖ Sedimentation/creaming of emulsions: influence of surface rheology, influence of surfactant concentration and of drop volume fraction. Foam drainage, case of HIPEs
┬╖&nb