Effect of gold nanoparticles on chemical oscillators: A comparative study of the experimental and simulated results

Addition of Au nanoparticles to a solution of chemical oscillators caused a concentration-dependent change in the oscillation dynamics. The oscillator used in the present system is BrO3--SO32-/HSO3- reaction in a continuous stirred-tank reactor. Increase in the Au nanoparticle concentration induced a decrease and increase in the periods in the high- and low-pH states, respectively, whereas total period was almost remained. We compared these experimental results with those obtained from the simulations involving protonation equilibrium, proton production, and proton consumption reactions. The comparison revealed that the change in the protonation equilibrium constant and the acceleration of the proton production reaction can explain the experimentally observed change in the oscillation dynamics. Our finding provides a novel insight into the mechanism of control of the chemical oscillation dynamics. Chemical oscillators are inherently stable toward chemical and physical fluctuations and lack flexible controllability owing to their characteristic features such as limit cycle and bifurcation; therefore, the addition of the metal nanoparticles to the chemical oscillators can offer a novel approach for the flexible and on-demand control of the chemical oscillations. (C) 2014 Elsevier B.V. All rights reserved.