Krishna Rajamani, van Baten Jasper M
Van 't Hoff Institute for Molecular Sciences, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands.
Phys Chem Chem Phys. 2017 Aug 9;19(31):20320-20337. doi: 10.1039/c7cp04101b.
For homologous series of linear chain molecules, there could be either a match, or mismatch, between the characteristic periodicity of the host structure and the characteristic length of the guest molecules. The major objective of this article is to highlight the influence of commensurateness, or incommensurateness, on both the adsorption and diffusion characteristics. Published experimental data, backed by molecular simulation results, are used to highlight the attendant non-monotonicity in adsorption strengths and diffusivities. We demonstrate the possibility of separating mixtures of n-alkanes, n-alcohols, and hydrocarbon isomers by appropriate and judicious choice of the dimensions, topology, and connectivity of the crystalline host material. Of particular practical interest are entropy-based separations that manifest at pore saturation conditions, relying on differences in the saturation capacities of the constituent species; the exploiting of such entropy effects is discussed with the aid of several examples.
对于线性链分子的同系物系列，主体结构的特征周期性与客体分子的特征长度之间可能存在匹配或不匹配。本文的主要目的是突出匹配或不匹配对吸附和扩散特性的影响。已发表的实验数据，辅以分子模拟结果，用于突出吸附强度和扩散率中随之而来的非单调性。我们证明了通过适当且明智地选择晶体主体材料的尺寸、拓扑结构和连通性，可以分离正构烷烃、正构醇和烃异构体的混合物。特别具有实际意义的是基于熵的分离，这种分离在孔饱和条件下表现出来，依赖于组成物种饱和容量的差异；借助几个例子讨论了对这种熵效应的利用。
