Gas phase adsorption of binary mixtures on planar walls in dispersive systems was studied by molecular dynamics simulations, extending a previous study on the adsorption of pure components. The interactions between all particles, fluid as well as solid, were described by the Lennard-Jones truncated and shifted potential with a cutoff radius of 2.5 σ. Two classes of fluid mixtures were studied: (a) symmetric mixtures, in which the pure components and also their interactions with the wall particles are the same but the unlike fluid–fluid interaction parameter is varied; (b) an asymmetric mixture, in which the dispersive energy of one fluid component was lowered, such that it becomes light-boiling. For the asymmetric mixture, both nonselective walls as well as walls with different selectivity for the two fluid components were investigated. Data on the surface excess, the thickness, and the structure of the adsorbate layer as well as on the selectivity were measured. The results give insight into how adsorption of binary mixtures is influenced by the different dispersive interactions between the fluids and between the fluids and the wall.

中文翻译：

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平面壁上对 Lennard-Jones 截断和位移流体的二元混合物的吸附

通过分子动力学模拟研究了分散系统平面壁上二元混合物的气相吸附，扩展了先前对纯组分吸附的研究。所有粒子、流体和固体之间的相互作用由 Lennard-Jones 截断和转移电位描述，截断半径为 2.5 σ。研究了两类流体混合物： (a) 对称混合物，其中纯组分及其与壁粒子的相互作用相同，但不同的流体 - 流体相互作用参数不同；(b) 一种不对称混合物，其中一种流体组分的色散能降低，使其变得轻沸。对于不对称混合物，研究了非选择性壁以及对两种流体组分具有不同选择性的壁。测量了表面过量、厚度和吸附层结构以及选择性的数据。结果深入了解二元混合物的吸附如何受到流体之间以及流体与壁之间的不同分散相互作用的影响。