混合基质膜的自由体积调控及分子传递机制

Mixed matrix membranes (MMMs) consisting of inorganic fillers filled in polymer matrix, are regarded as one of the most promising membranes in the future. Currently, the key issues for developing MMMs’ are the non-uniform dispersion of inorganic fillers and the defects or rigidification of organic-inorganic interface, leading to the decline of flux and selectivity. Therefore, this project proposed a novel strategy of “introducing molecular interactions to control the dispersion of inorganic fillers and the organic-inorganic interfacial behavior, in order to regulate free volumes and facilitate molecular transport in MMMS” to design and prepare high-performance MMMs with simultaneous improvement of flux and selectivity. In this proposal, multilevel molecular interactions were reasonably designed and constructed based on the group contribution method and solubility parameter theory, the formation mechanism and controllable preparation method of uniform and defect-free MMMs were systematically investigated; The molecular simulation and positron annihilation technique were employed to explore the regulation of micro-phase structures and tunable free volumes of the molecular interaction induced MMMs from an atomic level; The existence form of molecular channels and their synergetic transport mechanism in the MMMs were demonstrated upon the application of MMMs for alcohols recovery, so as to develop the theory for preparation and application of MMMs induced by molecular interactions. The implementation of this project will provide new ideas and theoretical basis for the development of new kind of MMMs.

由无机粒子填充聚合物基质构成的混合基质膜被认为是下一代最具发展潜力的分离膜之一。目前，无机填充物的分散不均以及有机-无机的界面缺陷与僵化阻碍膜通量或选择性的提升，是影响混合基质膜材料发展的核心问题。为此，本项目提出“通过分子作用力控制无机物分散与有机-无机界面行为，调控混合基质膜的自由体积并促进分子传递”的新思路，设计制备通量与选择性同步提高的高性能混合基质膜。项目基于基团贡献与溶解度参数理论合理设计与构建多层次的分子作用力，研究均匀分散、致密无缺陷的混合基质膜的形成机理与控制方法；运用分子模拟与正电子湮灭技术，从原子水平揭示分子作用力诱导下的混合基质膜微相结构与自由体积有序调控机制；以醇类有机物回收为目标体系，探讨混合基质膜中分子通道的存在形式及其协同传递机理，初步形成分子作用力诱导下的混合基质膜的构建与应用基础理论。项目实施为发展新型混合基质膜提供新的思路与理论依据。

本项目以高性能混合基质膜的设计与制备为背景，提出在混合基质膜中合理构建有机-无机多层次分子作用力，形成利于目标分子优先透过的分子传输通道，以突破聚合物膜渗透性与选择性此消彼长的瓶颈。项目实施过程中，紧密围绕“混合基质膜的自由体积有序调控”开展，通过对“混合基质膜中多层次分子作用力的构建与控制方法”、“混合基质膜的分子聚集态结构与自由体积的有序调控”、“混合基质膜的分子通道与协同传递机制”三个关键科学问题的深入研究，设计制备了PDMS、氧化石墨烯、MOF三大类高性能混合基质膜材料，突破了优先透丁醇膜、优先透水膜、CO2分离膜、H2分离膜、丁烷异构体分离膜的性能上限；结合分子动力学模拟与正电子湮灭、纳米压痕等先进表征技术，建立了膜微相结构与分离性能之间的构效关系；初步形成了基于分子作用力诱导的混合基质膜设计与制备基础理论，为混合基质膜及其它相关膜材料的开发提供了理论依据与技术参考。在Nature Materials, Chemical Society Reviews, Angewandte Chemie-International Edition, ACS Nano, Advanced Functional Materials, AIChE Journal, Journal of Membrane Science等化学、材料、化工或膜领域顶级期刊上发表SCI论文 25 篇；出版英文专著1部、参编英文著作2部；获授权发明专利 5 项，申请发明专利2 项；在国内外学术会议上作邀请报告6次，口头报告 2 次。