ABSTRACT
Soft-particle materials are complex forms of matter found in nature and often in high added-value products. These materials are composed of a disordered network of discrete particles, which can undergo mechanically large (elastic or inelastic) deformation (van Hecke 2010). Most cosmetics, food products, pastes, metal powders, emulsions, colloidal suspensions and biological cells are soft-particle systems.The interplay between disorder and large deformations of soft-particles leads to novel physical and mechanical properties that are out of reach within hard-particle models. High deformability of soft-particles under low confining pressure allows for high packing fractions beyond the jamming transition without particle rupture. Therefore, a combination of particle rearrangements and shape change controls the rheological properties such as compressibility and shear strength, as well as the microstructure of the material that can take a wide variety of forms depending on the particle properties (compressibility, plasticity…), interfacial forces (friction, adhesion…) between particles and environmental factors (suspending fluid, temperature…). The constituent particles of soft-particle materials are mostly macromolecular or granular aggregates, whose spatial extent ranges from 1 nm to
1 mm. Based on both composition and architecture, they can be divided into four groups (Bonnecaze & Cloitre 2010): colloidal-like particles, network particles, polymer-colloid systems and surfactant particles. Although all these particles are soft and elastic, the origin of their elasticity and deformability depends on their composition and structure.
