In very many situations, whether it be in fluids or materials for every day use, or in biological systems, matter is present in a highly dispersed form. It follows an extraordinary range of behaviour due to structural combinations, from the molecular to the mesoscopic and macroscopic scale. This field of research includes "soft matter", or the study of different forms of inorganic and organic objects on the mesoscopic scale, under thermal agitation, and interacting through dispersive or electrostatic forces.
The fundamental interest, the knowledge of the interaction energies between grains of the dispersed matter is closely linked to the industrial applications for powder, paste or emulsion transport and flow or creep properties of plastics with interesting mechanical behaviour. A related scientific domain concerns dry nanomaterials, in which the nanometric grain boudaries are closely linked. The mechanics of self-assembly and their application are the same for both liquids and solids : confinment, coupling and specific surface sensitive effects.