Segregation elastic properties

Figure 4. The elastic properties of some bimodal PDMS networks. Short chains were segregated by pre-reacting them with a limited amount of (tetrafunctional)...

The ability of particles to mix and their tendency to segregate depend on differences in their size, density, shape, elastic properties, surface characteristics, and magnitude of interparticle forces. The difference in particle size is probably the most important factor. Unlike immiscible liquid systems, the density differences play a relatively minor role in de-mixing or segregation of particulate mixtures. The large body of literature available on fluid mixing therefore cannot be used to predict or evaluate solids mixing applications. 

The existence of a physical structure has several important consequences. It determines a number of physical properties, notably mechanical ones viscosity, elasticity, consistency, fracture properties. Because of the physical inhomogeneity, some kinds of physical instability can occur, often manifest as a kind of segregation, and these are generally undesired. Chemical components are to some extent compartmentalized, which may affect their mutual reactivity, hence the chemical stability of a food. The compartmentalization also tends to affect flavor. The result of some process operations can greatly depend on the physical structure of the system, and several processes are intended to produce or to alter structure. 

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