Phase Separation in Soft Matter Physics
Today the range of objects under investigation in the physics of multicompo nent solutions has been considerably extended to include rod-like, rigid-chain and flexible polymer molecules, as well as others with oriented interactions. Due to their complex geometrical form and the increased number of system components in the solutions obtained, various irregular and regular struc tures may arise, e.g., molecular complexes and associates, micelles, vesicles, liquid-crystal formations, etc., depending on the component concentration and external conditions. Multicomponent liquid solutions remain the most difficult objects when it comes to describing the processes involved. This is due to the large number of independent variables and the existence of several multiphase separation regions in such systems, allowing several critical points to merge. Moreover, if a solution contains surfactants as components as well as molecules with some specific interactions (e.g., hydrogen-bonded molecules), one may observe a spontaneously emergent, macroscopically homogeneous, optically transparent state with an implicit manifestation of binarity (high dispersity), but never theless thermodynamically stable (microemulsions). Thus, in the absence of a macro-phase separation, some 'implicit' phase transitions are observed in the above systems. In these processes, the concentration fluctuation ampli tudes, correlation radius, and susceptibility reach a maximum, finite value.
First monograph devoted to soft-matter systems and their phase transitions