Reduction waves in the BZ reaction: Circles, spirals and effects of electric field

• Published in: Physica. D Vol. 84; no. 1; pp. 79 - 94
• Main Authors: Kaštánek, P., Kpsek, J., Šnita, D., Schreiber, I., Marek, M.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.06.1995
• ISSN: 0167-2789; 1872-8022
• DOI: 10.1016/0167-2789(95)00006-P

Spatiotemporal patterns in the Belousov-Zhabotinsky reaction medium in a Petri dish at low concentrations of malonic acid are studied experimentally and theoretically. Depending on the concentration of malonic acid, the interaction of reduction and oxidation front waves may lead to: (i) a disappearing reduction pulse wave, (ii) complex target structures, (iii) a stably propagating reduction pulse wave. A mechanical perturbation can lead either to reduction spirals or to healing effects causing heart-shaped structures. Imposed electric field causes a symmetry breaking of target patterns and can stabilize or destabilize the waves. A formal reaction-diffusion model reproduces qualitatively most of the experimentally observed phenomena in the absence of electric field. A modified Oregonator model that involves ionic migration describes well some experiments including those in the presence of electric field.