质子型离子液体交联的促进传递膜分离二氧化碳性能研究

Membrane separation of CO2 is the focus and difficulty of current research in Green Chemical Engineering. To overcome the difficulties, the research and exploitation of new polymer membranes with high permeability and selectivity is of great importance. Ionic liquids, as a kind of molten salts with unique properties, have been shown to be good impregnating compounds for the improvement of polymer membranes from the research work in recent years. However, few ionic liquid-modified polymer membranes of high CO2 separation performance have been found in literature till now. In view of this situation, and on the basis of the results obtained from the pre-research in our group, it is proposed in this project to design protic functionalized ionic liquids, multi-amine carboxylates, and crosslink them with epichlorohydrin (EPO) into ionic liquid polymer membranes, to develop novel and creative methods for the selective membrane separation of CO2. Keeping this idea in mind, it is suggested, as the first step, to investigate the molecular design, preparation and characterization of protic functionalized ionic liquids, and to observe the thermodynamic and kinetic characterics of CO2 dissolving into or permeating through the ionic liuqids. Then, the crosslinking of protic ionic liquids is performed to disclose its polymerization methodology, reaction mechanism, and product features in structure and property. The polymers crosslinked from protic ionid liquids are further made into gel membranes or composite membranes with a skin layer, to investigate the methodology and technology of membrane preparation. Finally, the gas permeation in supported ionic liuqid memnranes, gel membranes made from low crosslinked ionic liquid polymers, and composite membranes with a skin layer of high crosslinked ionic liquid polymers will be carried out to investigate the facillitated transport mechanism and to compare the performance difference of these three kinds of membranes. It is expected to obtain new ionic liuqid species, new membranes, novel methods of membrane preparation, and new data from the study of this project, and it is believed that this project may provide important fundamentals for the science and technology of gas separation membrane and carbon capture.

CO2气体膜分离是当前绿色化工过程研究的热点和难点，研究和开发具有高渗透和分离选择性的新型膜材料最为关键。用离子液体来改性聚合物膜材料是当前研究的新动向，但至今尚未获得高CO2分离性能的离子液体膜材料。为此，本项目结合前期预研，提出用质子型功能化离子液体经交联聚合的促进传递膜来创新CO2膜分离的新思路。围绕该思路，展开多胺-有机酸盐质子型离子液体的分子设计、制备、结构与性质研究，考察这类离子液体促进CO2溶解和渗透的热力学和动力学特征，探索其与环氧氯丙烷（EPO）交联聚合的方法、过程机理和产物结构性能，研究质子型离子液体交联的凝胶膜、皮层复合膜的制膜方法和工艺，测试并分析支撑离子液体的液膜、低交联离子液体的凝胶膜、及高交联离子液体的皮层复合膜这三者在促进CO2渗透分离机理和性能上的异同，以期获得离子液体新物种、新型膜材料、新制膜方法和一批新数据，为CO2膜分离和碳捕获科技进步提供研究基础。

CO2气体膜分离是当前绿色化工过程研究的热点和难点，研究和开发具有高渗透和分离选择性的新型膜材料最为关键。用离子液体来改性聚合物膜材料是当前研究的新动向，但至今尚未获得高CO2分离性能的离子液体膜材料。为此，本项目结合前期预研，提出用质子型功能化离子液体经交联聚合的促进传递膜来创新CO2膜分离的新思路。围绕该思路，展开多胺-有机酸盐质子型离子液体的分子设计、制备、结构与性质研究，考察这类离子液体促进CO2溶解和渗透的热力学和动力学特征，探索其与环氧氯丙烷（EPO）交联聚合的方法、过程机理和产物结构性能，研究质子型离子液体交联的凝胶膜、复合膜的制膜方法和工艺，测试并分析支撑离子液体的液膜、低交联离子液体的凝胶膜、及高交联离子液体的复合膜这三者在促进CO2渗透分离机理和性能上的异同。项目经4年探索，获得了包括可交联的多胺-有机酸盐在内的数十种新型质子型离子液体，在结构和性质表征的基础上考察并获得了一大批关于CO2溶解和渗透的热力学和动力学数据；获得了质子型离子液体的交联反应动力学和交联反应工艺参数；初步形成了离子液体交联的凝胶膜和复合膜的制备方法；实际制备了几种凝胶膜和复合膜材料。在此基础上测定了CO2、N2和CH4等在离子液体支撑液膜、凝胶膜、复合膜三类膜中的渗透行为。发现凝胶膜和复合膜和支撑液膜一样依然对CO2保持好的渗透性，且CO2/N2在凝胶膜和复合膜中的选择性分别高达225和80以上，而CO2/CH4在凝胶膜中的选择性则可达136，初步证明了交联离子液体凝胶膜和复合膜用于CO2选择性分离的可行性和可能性，为膜分离CO2的科技进步提供了理论和技术基础。项目成果具有重要的学术和应用价值。