Pattern Selection and Phase Fluctuations in Chemical Systems

Abstract

The spontaneous appearance of spatial structures far from thermal equilibrium has long been a puzzling phenomenon both from the experimental and theoretical points of view. Numerous questions related to pattern formation and pattern selection in physical, chemical and biological systems still remain unanswered [1, 2]. Contrary to the case of convective patterns, the spatial structures which appear in chemically active media have often been considered as spurious effects, bad experimentation and aroused at first little interest. For a long time, the activity remained therefore on the theoretical level, in the framework of the theories of dissipative structures and nonequilibrium phase transitions. Fortunately chemical selforganization is now observed in an evergrowing class of systems and its relationship to actual problems from morphogenesis to materials sciences is now well accepted. Moreover, an enormous amount of computational and experimental work is now being reported where chemically active media exhibit multiple steady states, periodic solutions, wave phenomena and mosaic-like patterns and quantitative comparison between theoretical and experimental data will soon be available [3–4].