表面部分成膜金属阳极溶解模型及其振荡与混沌行为  

MODEL OF ANODIC DISSOLUTION OF METAL WITH MOH AND MO FILMS AND ITS CHAOTIC DYNAMICS

作　　者：李学良[1] 鲁道荣[1] 朱云贵[1] 何建波[1] 王华林[1] 

机构地区：[1]合肥工业大学化工学院应用化学研究所,合肥230009

出　　处：《金属学报》2001年第5期493-498,共6页Acta Metallurgica Sinica

基　　金：国家自然科学基金29976009;教育部高等学校骨干教师计划资助项目200601B2

摘　　要：提出了金属表面生成ＭＯＨ和ＭＯ两种膜的阳极溶解过程反应模型，导出了溶解反应动力学方程．对溶解过程中反应物浓度和表面覆盖度等系统状态变量的不动点进行了线性稳定性的分析，研究了不动点的稳定性．对模型的状态变量全局运动状态和行为进行了计算机模拟，研究了其中的振荡行为，分析了反应参数对动力学行为的影响．结果表明：模型中存在膜的生成与溶解导致溶解过程的复杂化，该动力学模型呈现十分丰富的振荡和混沌行为，反应速率常数的改变导致反应物由稳态至非稳态的变化，呈现出溶解离子浓度和表面膜覆盖度的周期性及非周期性振荡，非周期性振荡具有混沌的特性．探讨了溶解过程中物质浓度、ＭＯＨ（ａｄ）和ＭＯ（ａｄ）的覆盖度随时间变化的动态特征，分析和讨论金属阳极溶解过程中基本规律．成膜过程中ＭＯ（ａｄ）、金属基体Ｍ和反应生成ＭＯＨ（ａｎ），构成反应过程中的反馈，表征为反应中存在非线性及多种耦合作用．模型中动力学速率常数等参数改变，使得耦合在适当的条件下得到强化，这是复杂振荡产生的主要原因．A reaction mathematical model for anodic dissolution of metal covered by MOH and MO films was established, and the dynamic behavior of reaction was investigated. The stability of the equilibrium state for dissolution reaction model was examined by means of linear stability analysis, the global behavior of the model is studied by numerical simulation and the influence of the reaction rate constant on the dynamic characteristics of the model is discussed. The dynamic characteristics are affected by reaction parameters and this model exhibits remarkably rich dynamics, including Hopf bifurcation, mixed mode of oscillations and chaos. The formation and dissolution of MOH and MO films results in the complication of metal dissolution process. The feedback in the reaction of MO(ad), MOH(ad) and M causes nolinearity and multi-coupling action. The strengthening of the coupling action with reaching critical value for the surface coverage of MO(ad) film results in complex attractor.

关 键 词：阳极溶解 电化学振荡 化学混沌 

分 类 号：O646.54[理学—物理化学] O643.1[理学—化学]