IV - The formation of disperse systems

Publisher Summary Disperse systems occupy an intermediate position between macroscopic heterogeneous systems and molecular solutions (homogeneous systems), and thus, can be prepared via two main paths: by dispersing the macroscopic phases (dispersion path) or by condensation, either in true solutions or in homogeneous single component systems (condensation path). In most cases, the formation of disperse systems requires work. This work can either be introduced from the outside, for example, in the form of mechanical work, or be generated within the system through various processes, including chemical reactions. The resulting disperse systems are thermodynamically in disequilibrium, and their prolonged existence is impossible without additional stabilization. In the absence of the latter, the system is unstable and a particular particle size or particle size distribution cannot be maintained, that is, the particles spontaneously coarsen and finally the disperse system collapses. A number of disperse systems may form as a result of the spontaneous dispersion of a macroscopic phase. These systems, referred to as lyophilic, are thermodynamically in equilibrium and do not require any additional stabilization.