磁场诱导CNTs有序排列的高分子-无机杂化膜的制备

Polymer-inorganic hybrid membranes, which combine the advantages of polymeric membranes and inorganic membranes, have become one of the hot topics in membrane research. In this study, poly vinyl alcohol is selected as the polymer matrix. The carbon nanotubes which covered by ferroferric oxide nanoparticles (m-CNTs) are selected as the inorganic materials. The carbon nanotubes with high magnetic responsive ferroferric oxide nanoparticles (m-CNTs) are selected as the inorganic materials. Magnetic field-induced method is uitilized to fabricate the aligned polymer-inorganic hybrid membranes, since the m-CNTs with high magnetic responsive can be easily controlled in the magnetic filed. The orientation and spatial distribution of m-CNTs are dominated by intensity and direction of the magnetic field. Aligned m-CNTs in the transmembrane direction are constructed as water channels to promote the water transportation. Influence of aligned m-CNTs on the structure (especially the free volume properties) and separation performance are investigated to probe the effect of m-CNTs on the transportation of penetrant molecules in the hybrid membranes. The dehydration of ethanol by pervaporation is selected as the models to investigate the transportation mechanism of water in the m-CNTs.The approach and theory to transcend the "trade-off" limitation between permeability and permselectivity of membranes are further investigated by characterizing the relationship between the structure and separation performance. Hopefully, this study will offer some important conclusion in designing and fabricating polymer-inorganic hybrid membranes for pervaporation with high separation performance.

高分子-无机杂化膜能够综合高分子膜和无机膜的优点，已经成为膜领域的研究热点之一。本项目选用聚乙烯醇为高分子主体材料，选用表面包覆四氧化三铁纳米颗粒的碳纳米管（m-CNTs）为无机材料。利用m-CNTs的高磁响应性,通过改变外磁场的方向、强度等控制杂化膜内m-CNTs的排列取向和空间分布，在跨膜方向构建排列有序的m-CNTs作为水分子传递的通道,制备无机材料有序排列的高分子-无机杂化膜。利用m-CNTs促进水分子传递特性,提高杂化膜的分离性能。以乙醇脱水的渗透蒸发过程为研究对象，研究m-CNTs改善杂化膜的结构（特别是自由体积特性）和促进水分子传递的机理，拓展杂化膜突破渗透性和选择性之间"trade-off"制约的理论，为高性能高分子-无机杂化渗透蒸发膜的设计和制备提供指导。

高分子-无机杂化膜能够综合高分子膜和无机膜的优点，已经成为膜领域的研究热点之一。本项目选用海藻酸钠、壳聚糖、聚二甲基硅氧烷、Pebax嵌段共聚物等为高分子主体材料，选用亲水化改性Fe3O4纳米颗粒、负载Fe3O4纳米颗粒的的碳纳米管、二维氧化石墨烯和氮化碳、纳米多孔金属有机骨架材料等多种纳米材料为无机杂化材料，制备高分子-无机杂化膜。通过外磁场、纳米材料各项异性、亲疏水性或密度差异等调控杂化膜内纳米材料的排列取向和空间分布，调控杂化膜的微观结构（特别是自由体积特性），在杂化膜内构建水分子传递通道，提高杂化膜用于乙醇水共沸体系、清洁油品生产等小分子液体混合物分离过程的性能。本项目的实施，拓展了杂化膜突破渗透性和选择性之间“trade-off”制约的理论，为高性能高分子-无机杂化渗透蒸发膜的设计和制备提供了指导。本项目执行期间发表SCI论文18篇，其中SCI一区论文13篇。申请发明专利9项。培养博士5名，硕士9名。参加国际学术会议3次，国内学术会议6次。