Aranovich G L, Wetzel T E, Donohue M D
Department of Chemical and Biomolecular Engineering, The Johns Hopkins University, Baltimore, Maryland 21218, USA.
J Phys Chem B. 2005 May 26;109(20):10189-93. doi: 10.1021/jp050059y.
Recently, it has been shown that adsorption of gases on solid surfaces often leads to repulsive forces between adsorbate molecules. In this paper, adsorption of molecules on a one-dimensional lattice is considered for repulsive interactions between adsorbate molecules. Exact adsorption isotherms are calculated and analyzed for finite and infinite chains of active sites (i.e., a one-dimensional lattice). Although the mathematical solution for the one-dimensional lattice is known for attractive and repulsive systems, the effects of intermolecular repulsions on adsorption behavior have not been studied in detail previously. Similarly, though the mathematics for the one-dimensional lattice has been solved for any arbitrary lattice length, the effect of finite size on adsorption isotherms for repulsive adsorbate interactions has never been examined. This paper shows that spatial confinement and strong attraction to active sites can cause compression of an adsorbed phase and that repulsive interactions between adsorbed molecules result in steps in the adsorption isotherms. For higher chemical potentials, the density increases until saturating at the lattice capacity. These steps in the adsorption isotherm have not been observed in previous studies of lattice systems. For small lattices, the adsorption behavior was found to be fundamentally different for even and odd values of lattice length. Lattices with an even number of lattice sites can have two steps in the adsorption isotherm, whereas systems with an odd number of sites only have a single step occurring at a coverage slightly greater than half the lattice capacity.
最近的研究表明，气体在固体表面的吸附通常会导致吸附质分子之间产生排斥力。在本文中，我们考虑了分子在一维晶格上的吸附，以研究吸附质分子之间的排斥相互作用。我们计算并分析了有限和无限活性位点链（即一维晶格）的精确吸附等温线。虽然一维晶格的数学解在吸引和排斥系统中是已知的，但分子间排斥对吸附行为的影响此前尚未得到详细研究。同样，尽管对于任意晶格长度的一维晶格数学问题已经得到解决，但有限尺寸对排斥吸附质相互作用的吸附等温线的影响从未被研究过。本文表明，空间限制和对活性位点的强吸引力会导致吸附相的压缩，并且吸附分子之间的排斥相互作用会导致吸附等温线出现台阶。对于较高的化学势，密度会增加直至达到晶格容量时饱和。吸附等温线中的这些台阶在先前的晶格系统研究中并未观察到。对于小晶格，发现晶格长度的奇偶值对应的吸附行为存在根本差异。具有偶数个晶格位点의晶格在吸附等温线中可能有两个台阶，而具有奇数个位点的系统在覆盖率略大于晶格容量一半时只有一个台阶。 （注：原文中“even number of lattice sites”和“odd number of sites”翻译时前面加了“个”使表达更通顺，“의”疑为多余字符，按照正常翻译处理）
