BREAKDOWN OF SYMMETRY, SPATIOTEMPORAL PATTERNS AND TRAVELING WAVES INOXYHALOGEN-SULFUR SYSTEMS

Spatial structures can occur in unstirred, originally homogeneous, non -linear chemical systems far from equilibrium. Chemical waves are conc entration variations of chemical species propagating in a system. Oxyh alogen-sulfur (compound) systems have produced novel chemical waves an d spatial inhomogeneities when maintained far from equilibrium. Oxyhal ogen-sulfur reactions proceed accompanied by large production of heat and protons at the wavefronts. This introduces density gradients induc ed by the travelling fronts as well as free convection which greatly a ffects wavefront velocities. By allowing heat to be a factor in the wa ve propagation and pattern formation, these systems much more closely resemble naturally occurring biological waves as well as flames. The r ole of hydrodynamics is also examined in the formation of spatio-tempo ral patterns.