Spatial bistability in a pH autocatalytic system: from long to short range activation.

摘要: The acid-auto-activated chlorite-tetrathionate reaction is studied in a one-side-fed spatial reactor. It was previously shown that these conditions the unstirred reaction-diffusion system can generate oscillatory and excitable states even though under well-stirred nonequilibrium only steady-state bistability observed. Numerical simulations suggest temporal instabilities result from long-range activation by rapidly diffusing protons. We study here experimentally numerically effect of introducing into this macromolecular carboxylate species reduce effective diffusivity Consistent with original assumption, introduction such slow mobility proton-binding quenches both excitability dynamics. Within domain direction propagation an interface between two steady depends on control parameter value. elaborate fact beyond low critical concentration species, stability limit "thermodynamic" branch state does not depend concentration. Despite relative simplicity kinetic model used numerical simulations, results are quasi-quantitative agreement experimental observations.