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

The phenomenon of spatial bistability has recently been proposed to underst and a number of paradoxical results obtained in experiments on nonequilibri um 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 th at the chlorine-dioxide-iodide reaction, taken as a prototypic example of a large class of reactions, should exhibit spatial bistability. The theoreti cal and numerical results are supported by experiments performed in special ly designed reactors. This spatial bistability introduces an additional geo metric 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. (C) 2000 Elsevier Science B .V. All rights reserved.