Colloids

At the end of the course, students will be able to:
- describe the origin of the kinetic stability of emulsions and foams
- describe the behavior of amphiphilic molecules at interfaces
- choose the functional ingredients for making a food emulsion or foam.

General thermodynamics

INTRODUCTION
Definition of a colloid, classification of colloids
ELEMENTS OF SURFACE THERMODYNAMICS
Notion of surface and interfacial tension
Thermodynamic stability and metastability
SURFACE AGENTS
Surfactants
Surfactant behavior in solution (micellization, Kraft point, polymorphism)
Adsorption of surfactants at interfaces (notion of interfacial film, two-dimensional film pressure, Gibbs equation)
Proteins (adsorption at interfaces and denaturation)
EMPIRICAL RULES OF FORMULATION
1- BANCROFT's rule
2- HLB rule (Hydrophile-lipophile balance)
PREPARATION OF EMULSIONS
INTERACTIONS AT COLLOIDAL SCALE
1- Van der Waals attraction, electrostatic repulsion, steric forces, depletion interaction,
2- Flocculation of dispersions (DLVO model)
DESTRUCTION OF METASTABLE DISPERSIONS
Ostwald ripening
Coalescence
FORMULATION IN FOOD
Milk and dairy products
Chocolate
Mayonnaises
Vinaigrettes

Physical and analytical chemistry

Foundations of colloid science, Vol. 1 and 2, Hunter Colloidal dispersions, Russel, Daville and Showalter
Gouttes, Bulles, Perles et Ondes, de Gennes, Brochart-Wyart, Quéré