Interactions in Soft condensed matter

Pascal Hébraud (IPCMS)
pascal.hebraud[at]ipcms.unistra.fr

Interactions between elementary soft condensed matter objectsplay a key role in the description of their structure, their organization and their dynamics. We will not focus on a particular soft matter system, but of interactions that enter in their description. Nevertheless, we will illustrate each kind of interaction by examples chosen among soft matter systems.

1. Molecular forces

(a) Van der Waals interactions interactions between molecules

interactions between macroscopic bodies

(b) Electrostatic forces in electrolytes

Electrostatic self-energy of an ion : Debye-Huckel theory;
Poisson-Boltzmann theory;
Condensation of ions;

2. Entropic forces
(a) Two component systems

Effective hamiltonian
Depletion interactions

(b) Polymer systems

Tension of a polymer chain;
Steric repulsion.