Institute of Chemistry, L. Eötvös University, P.O. Box 32, H-1518 Budapest 112, Hungary.
J Phys Chem A. 2010 Jul 8;114(26):7063-9. doi: 10.1021/jp1037624.
In this report we present an experimental study on the spatiotemporal dynamics of the iodate-sulfite-ferrocyanide and the iodate-sulfite-thiourea systems. Both systems are capable of producing nontrivial reaction-diffusion patterns when they are operated in a one-side-fed open spatial reactor. An important parameter of these types of reactors is the time scale of the diffusive feed, which is determined by the "thickness" of the gel and diffusion coefficients of the chemicals. A conical shape gel is used to study the effect of the thickness gradient on the dynamics. We show that spatiotemporal oscillations stop below a critical thickness. It is demonstrated that the period of the oscillations is determined by the time scale of the inhibitory kinetics and the time scale of the diffusive feed together. In the case of the iodate-sulfite-thiourea system we observed the appearance of a stationary iodine front in the presence of the oscillating pH front. An experimentally supported kinetic explanation is given to account this phenomena.
在本报告中，我们进行了一项关于碘酸盐-亚硫酸盐-亚铁氰化物和碘酸盐-亚硫酸盐-硫脲体系的时空动力学的实验研究。当这两个体系在单侧进料开放式空间反应器中运行时，它们都能够产生非平凡的反应-扩散模式。这类反应器的一个重要参数是扩散进料的时间尺度，它由凝胶的“厚度”和化学物质的扩散系数决定。我们使用锥形凝胶来研究厚度梯度对动力学的影响。我们表明，在临界厚度以下，时空振荡会停止。实验表明，振荡的周期由抑制动力学的时间尺度和扩散进料的时间尺度共同决定。在碘酸盐-亚硫酸盐-硫脲体系的情况下，我们观察到在振荡 pH 前沿的存在下出现了一个稳定的碘前沿。我们给出了一个实验支持的动力学解释来解释这一现象。
