Organic solvent reverse osmosis (OSRO) is an emerging and promising technology for the separation of organic mixtures, which is realized by differential transport rates of organics through polymer membranes. However, the solvent transport characteristics and separation mechanism within OSRO systems remain unclear. Herein, we investigate the solvent transport behavior in polymer membranes with intrinsic microporosity by combining nonequilibrium molecular dynamics simulations with solvent permeation examinations. The results indicate that organic molecules permeate through the micropores in a clustered state driven by both pressure and concentration gradients. The selectivity of solvents is co-determined by their sorption and diffusion in the swollen polymer membranes with a microporous character. The sorption selectivity is predominant in the overall selectivity toward polar ethyl ether/n-butanol separation, whereas diffusion selectivity is more critical in nonpolar 1,3,5-triisopropylbenzene/toluene separation. Generally, this work provides valuable insights into the development of next-generation OSRO membranes for solvent separation.

中文翻译：

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用于有机溶剂反渗透的具有固有微孔性的聚合物膜中的溶剂传输行为


有机溶剂反渗透（OSRO）是一种新兴且有前途的有机混合物分离技术，它是通过有机物通过聚合物膜的不同传输速率来实现的。然而，OSRO 系统内的溶剂传输特性和分离机制仍不清楚。在此，我们通过将非平衡分子动力学模拟与溶剂渗透检查相结合，研究了具有固有微孔性的聚合物膜中的溶剂传输行为。结果表明，有机分子在压力和浓度梯度的驱动下以聚集状态渗透通过微孔。溶剂的选择性由它们在具有微孔特性的溶胀聚合物膜中的吸附和扩散共同决定。吸附选择性在极性乙醚/正丁醇分离的总体选择性中占主导地位，而扩散选择性在非极性 1,3,5-三异丙苯/甲苯分离中更为关键。一般来说，这项工作为开发用于溶剂分离的下一代 OSRO 膜提供了宝贵的见解。