Pattern formation in the ferrocyanide-iodate-sulfite reaction: The control of space scale separation

摘要: We revisit the conditions for development of reaction-diffusion patterns in ferrocyanide-iodate-sulfite bistable and oscillatory reaction. This hydrogen ion autoactivated reaction is only example known to produce sustained stationary lamellar a wealth other spatio-temporal phenomena including self-replication localized domain spots, due repulsive front interactions parity-breaking bifurcation (nonequilibrium Ising–Bloch bifurcation). show experimentally that space scale separation necessary observation mediated by presence low mobility weak acid functional groups. The such groups was overlooked original observations made with hydrolyzable polyacrylamide gels. missing information difficult reproduce frustrated further experimental exploitation fantastic potentialities this system. Using one-side-fed spatial reactors filled agarose gel, we can all previous pattern observations, particular labyrinthine patterns, introducing, above critical concentration, well controlled amounts polyacrylate chains gel network. use two different geometries (annular disk shapes) provide complementary on actual three-dimensional character patterns. also reinvestigate role feed parameters system exhibits both bistability large-amplitude pH oscillations associated typical cross-shape diagram. method presented here be adapted large number reactions, since iodate-sulfite-ferrocynide prototype these systems.