团队博士刘亦琳关于水蒸气在不同复合膜内输运行为的分子模拟研究发表于能源类TOP期刊Applied Energy。

Dr. Liu Yilin published a paper titled “A molecular level based parametric study of transport behavior in different polymer composite membranes for water vapor separation” in Applied Energy.

为了了解复合材料性能的影响机理，定量预测复合膜在实际应用中的空气除湿性能，本文采用巨正则蒙特卡罗（GCMC）和分子动力学（MD）模拟方法，详细分析了选择层与支撑膜之间的界面相互作用，探讨了各种复合膜的界面稳定性和相容性，评价了各种复合膜的物理化学特性（密度、分数自由体积、溶解度参数和内聚能密度）和输运性能（溶解度、扩散率、渗透性和选择性）。研究结果发现，相比于PVA复合膜， PDMS复合膜表现出更强的界面相互作用。PVA聚合物的亲水性和极性使得气体分子与PVA膜之间的相互作用更强。根据溶液扩散机理，PVA-PVDF膜的水蒸气渗透性在所有复合膜中最佳，Barrer为3121.38。本研究揭示的水蒸气微观输运机理将为高性能空气除湿复合膜的设计提供理论基础。

To understand the mechanisms dominating material properties and quantitatively predict the air dehumidification performance of the composite membranes in practical applications, various models combined with different polymeric materials and porous support membranes were developed and investigated by using grand canonical Monte Carlo (GCMC) and Molecular dynamics (MD) simulation methods. The interfacial interactions between the selective layer and the support membrane were analyzed in detail to explore the interface stability and compatibility of various composite membranes. The physical characteristics (density, fractional free volume, solubility parameter and cohesive energy density) and transport properties (solubility, diffusivity, permeability and selectivity) of various composite membranes were parametrically evaluated. The polydimethylsiloxane (PDMS) composite membranes exhibited stronger interfacial interaction in comparison to the PVA composite membranes. The hydrophilicity and polarity of polyvinyl alcohol (PVA) polymer resulted in a stronger interaction between the gas molecules and the PVA membrane. According to the solution–diffusion mechanism, the PVA-PVDF membrane presented the optimal H2O permeability of 3121.38 Barrer among all composite membranes. The microscopic mechanisms revealed in this work would lay a solid theoretical foundation for the design of high performance composite membrane for air dehumidification.

文章链接：http://doi.org/10.1016/j.apenergy.2022.120007