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arXiv 0907.5569cond-mat.mtrl-sci
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变性质表面上的吸附

Adsorption on a Surface with Varying Properties

A. S. Usenko

摘要:

本文提出了一个自洽模型,考虑了气体分子在吸附-脱附过程中吸附剂表面吸附性质的变化,引入了一个表征吸附分子与极化介质相互作用的无量纲耦合参数。当耦合参数大于某一临界值且气体浓度在某一区间内时,系统可以被解耦。我们表明,所提出的模型的框架内获得的吸附等温线本质上不同于Langmuir等温线,并建立Zeldovich滞后是可能的。详细分析了表面覆盖的动力学过程。我们表明,考虑到在吸附-脱附过程中的表面的吸附性质的变化导致新的现象:一个“准定”状态的情况下的过阻尼近似和自振荡的系统在一般情况下。

英文摘要:

We propose a self-consistent model taking into account variations in adsorption properties of the adsorbent surface in the process of adsorption--desorption of molecules of gas on it. We introduce a dimensionless coupling parameter that characterizes the interaction of an adsorbed molecule with polarized medium. It is established that the system can be bistable if the coupling parameter is greater than a critical value and the concentration of gas belongs to a certain interval. We show that the adsorption isotherms obtained within the framework of the proposed model essentially differ from the Langmuir isotherms and establish that the Zeldovich hysteresis is possible. The kinetics of the surface coverage is analyzed in detail. We show that taking account of variations in adsorption properties of the surface in the process of adsorption--desorption leads to new phenomena: a "quasistationary" state in the case of the overdamped approximation and self-oscillations of the system in the general case.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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