Concentration Wave Propagation in Two-dimensional Liquid-phase Self-oscillating System

OSCILLATING chemical reactions are interesting, not only in themselves but as models of a number of important biological processes1–5. Oscillating reactions have been described in which cerium (or manganese) ions catalyse the oxidation of analogues of malonic acid by bromate6–8. Oscillations in the concentrations of oxidized and reduced forms of the catalyst cause oscillations in the solution colour, while stirring leads to forced synchronization of oscillations throughout the whole volume. In the absence of stirring, periodic propagation of concentration waves occurs in certain conditions, and such a phenomenon in a one-dimensional system (a long tube) has been described9,10. Our work deals with patterns in a thin layer of solution (two-dimensional system).