title: Controlled excitations of the Belousov-Zhabotinsky reaction: Experimental procedures.
abstract: The purpose of this research was to explore the unstirred, ferroin-catalyzed Belousov-Zhabotinsky (BZ) reaction as an experimental model for the response of excitable media to small perturbations (slightly larger than the threshold for excitations). Following Showalter et al. (Showalter, K.; Noyes, R. M.; Turner, H. J.Am. Chem. Soc. 1979, 101, 7463-69), we used a positively biased silver electrode to release silver ions into a BZ reaction mixture, removing bromide ions and causing an excitation if sufficient bromide was removed. We found (1) a scaling region in which the delay before activation increased linearly as the size of the perturbation decreased, qualitatively consistent with but not fully explained by the Oregonator of Field et al. (Field, R. J.; Körõs, E.; Noyes, R. M. J. Am. Chem. Soc. 1972, 94, 8649-64); (2) evidence for a 10 s oligomerization time scale; and (3) that activations were always delayed until after the end of a pulse of current, with the delay essentially constant for sufficiently long pulses, an effect not seen in simple ODE models but consistent with the anomalously large current apparently required for activation (Showalter, K.; Noyes, R. M. J. Am. Chem. Soc. 1976, 98, 3730-31) and explainable by bromide transport. Overall, the BZ system appeared to be well-suited as an experimental prototype, despite its complexity.
authors.affiliation: Department of Chemistry, Hofstra University, Hempstead, New York 11549-1510, USA.
authors.forename: Catalina
authors.initials: C
authors.lastname: Peralta
authors.forename: Claudia
authors.initials: C
authors.lastname: Frank
authors.forename: Alex
authors.initials: A
authors.lastname: Zaharakis
authors.forename: Carolyn
authors.initials: C
authors.lastname: Cammalleri
authors.forename: Matthew
authors.initials: M
authors.lastname: Testa
authors.forename: Stephen
authors.initials: S
authors.lastname: Chaterpaul
authors.forename: Christian
authors.initials: C
authors.lastname: Hilaire
authors.forename: Daniel
authors.initials: D
authors.lastname: Lang
authors.forename: Daniel
authors.initials: D
authors.lastname: Ravinovitch
authors.forename: Sabrina G
authors.initials: SG
authors.lastname: Sobel
authors.forename: Harold M
authors.initials: HM
authors.lastname: Hastings
mesh_terms: D001965:Bromides / Q000737:chemistry*; D002384:Catalysis; D003198:Computer Simulation; D007477:Ions; D007700:Kinetics; D008956:Models, Chemical; D010618:Phenanthrolines / Q000737:chemistry*; D012834:Silver / Q000737:chemistry*; D013995:Time
chemical_list: D001965:Bromides; D007477:Ions; D010618:Phenanthrolines; C001635:ferroin; D012834:Silver