Theoretical and experimental studies of spatial bistability in the chlorine-dioxide–iodide reaction

The phenomenon of spatial bistability has recently been proposed to understand a number of paradoxical results obtained in experiments on nonequilibrium chemical patterns performed in open reactors made of a thin film of gel fed from one side. On the basis of a realistic kinetic model, we predict that the chlorine-dioxide–iodide reaction, taken as a prototypic example of a large class of reactions, should exhibit spatial bistability. The theoretical and numerical results are supported by experiments performed in specially designed reactors. This spatial bistability introduces an additional geometric dimension in the system which is generally overlooked. We elaborate on the role that this additional complexity can play in the observation of patterns associated to fronts in such reactors.