Spatiotemporal Pattern Formation and Chaos in the Belousov-Zhabotinsky Reaction in a Reverse Microemulsion

We study the spatiotemporal behavior of the oscillatory Belousov‐Zhabotinsky (BZ) reaction in a reverse microemulsion consisting of water, octane and the surfactant sodium bis(2‐ethylhexyl)sulfosuccinate (AOT). By varying the microemulsion composition, we can “tune” its structure, specifically the size and spacing between the nanometer‐sized water droplets in which the polar BZ reactants reside. We find a remarkable array of pattern formation as the microemulsion structure and BZ chemistry are varied. Behaviors observed include stationary Turing patterns, traveling and standing waves, spirals, targets, antispirals and antitargets (which travel into rather than out from their center), and spatiotemporal chaos. A simple reaction‐diffusion model, which accounts for the BZ chemistry and the differential diffusion of species within water droplets and in the bulk oil phase, is able to reproduce nearly all of the observed behavior.