可光交联PEG-Amidine复合型CO2选择透过功能膜的制备及其气体渗透机制研究

The preparation of polymeric membranes for carbon dioxide(CO2) seperation has been a global project in many fields, such as developing new energy, protecting environment and life-supporting in air and space. The polymer with ethylene glycol(EG) units has been considered to be one sort of polymers with highest CO2 permeation selectivity.Another hotspot, facilitated transport membrane has recently been developed rapidly and regarded as another way to achieve higher CO2 peameation selectivity with low energy consumption. In this proposal, we are inspired from the process of transportation of CO2 in our body. Carbon anhydride enzyme(CA),as a carrier, has strong interaction with CO2 molecules and delivers them in organisms. Analogously, in our early work, we found amidine group can be another competent carrier to transport CO2 molecules, due to its particular structure that has reversible reaction with CO2 molecules. In this proposal, two kinds of UV-crosslinkable PEG-Amidine composited membranes will be prepared through self-assembly of the block copolymer and Layer-by-Layer electrostatic self-assembly, respectively. By investigating the correlation between the microcosmic structure and macroscopic gas permeation property of membranes, we propose to have a close insight of probing the influence of the different component fraction of each functional unit (i.e.: PEG unit and amidine group) on the inner structure and macroscopic gas permeation property of membranes. In the meanwhile, a possible synergetic effect of PEG and Amidine units on CO2 permeation will be investigated. To be breif, we would explore the mechanism of CO2 molecules permeation in the various affection environments which are created by functional groups in our membranes. We believe this project will certainly benefit the preparation of CO2 separation membranes with both high mechanical stability and high gas permeation properties.

采用聚合物膜对二氧化碳（CO2）选择性分离在新能源开发、环境保护以及航空航天生命保障等诸多领域都具有重要意义。主体PEG型聚合物被认为是当前具有最高CO2选择透过性的聚合物材料之一。此外，促进传递膜的飞速发展使CO2高效低能耗选择分离成为可能。本项目从生命体中碳酸酐酶（CA）选择性传递CO2过程得到启发，在前期工作基础上，拟利用与CA作用机制相似的Amidine（脒）基团作为CO2传递载体，分别通过嵌段共聚物自组装和静电层层自组装两种方法构筑两种类型可光交联PEG-Amidine复合型促进传递膜。拟通过研究两种复合膜微观结构与宏观气体透过性质之间的关系，考察膜层中两种功能单元的组分比例及微观复合形态对膜层结构和宏观气体透过性质的影响，论证两种结构单元对CO2渗透可能的协同作用，进而探索CO2在不同作用环境下的渗透规律及机理，为制备膜层稳定且具有高选择透过性能的CO2分离膜提供理论和实验依据

本项目拟通过分子设计合成，利用仿生原理，模拟碳酸酐酶作为载体传递CO2的过程，实现EG基团和Amidine基团对CO2选择透过性的协同作用，以期获得结构稳定的高选择性CO2透过膜材料。项目按计划完成了相关主体聚合物和客体小分子的设计合成和结构表征，分别得到项目书中可光交联PEG-Amidine型复合膜所需的嵌段共聚物和聚电解质分子。利用嵌段聚合物自组装特性，通过退火自组装过程构筑膜层内部有序柱状微相结构。通过设计调控嵌段共聚物分子中不同嵌段、嵌段组分比例以及后处理方法，研究嵌段种类、嵌段组分比例以及交联等对CO2的选择透过性质的影响。设计合成了同时含EG基团和Amidine基团两种结构单元的嵌段共聚物PEG-b-PAD和PEG-b-PMMA-b-PAD，制备了具备高选择透过性能的CO2气体分离膜。验证了这两种基团对CO2渗透的协同作用。在此基础上，本项目增加了“CO2智能仿生离子通道以及石墨烯基气体响应材料的设计与制备”的研究内容，提升了含Amidine基等响应性小分子的应用广度以及项目的研究深度。以第一作者或者通讯作者发表SCI论文18篇，申请专利3项。其研究结果为制备膜层稳定且具有高选择透过性能的CO2 分离膜提供了有力的理论指导和实验依据。