Abstract A combination of ab initio and classical molecular dynamic simulations was used to explore the adsorption/desorption and diffusion characteristics of ion-exchange resins for extraction of organic anions in electrically-driven separation processes. We considered two classes of carboxylate mixtures that are commonly encountered in bioprocessing separations: a short chain fatty acid mixture (acetate/butyrate) and an aromatic mixture (ferulate/coumarate). The suitability of several resin materials including PFC100E, IRC86, PFA444 and IRA67 was interrogated. The decomposition of the interaction energies by the symmetry-adapted perturbation theory and the classical molecular dynamic simulations of organic diffusion together reveal that the geometries of the organic anions and the functional groups of the resins, as well as their Columbic interactions, are the controlling factors in the diffusion process of the organic compounds in these resins. Classical simulations also show that modifying the functionality of resin beads, the magnitude of electric fields, and the ratio of organic mixtures may provide an effective way to control the diffusion rate and obtain selective separation of these organic mixtures. Finally, a general suggestion for favorable separation conditions is summarized.

中文翻译：

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使用离子交换树脂分离有机阴离子的原子级理解

摘要 结合从头算和经典分子动力学模拟，研究了离子交换树脂在电驱动分离过程中萃取有机阴离子的吸附/解吸和扩散特性。我们考虑了生物处理分离中常见的两类羧酸盐混合物：短链脂肪酸混合物（乙酸盐/丁酸盐）和芳香族混合物（阿魏酸盐/香豆酸盐）。对包括 PFC100E、IRC86、PFA444 和 IRA67 在内的几种树脂材料的适用性进行了询问。通过对称性适应微扰理论和有机扩散的经典分子动力学模拟对相互作用能的分解揭示了有机阴离子的几何形状和树脂的官能团，以及它们的 Columbic 相互作用，是这些树脂中有机化合物扩散过程的控制因素。经典模拟还表明，改变树脂珠的功能、电场强度和有机混合物的比例可以提供一种有效的方法来控制扩散速率并获得这些有机混合物的选择性分离。最后，总结了有利分离条件的一般建议。