自具纳米通道固定载体膜的制备及CO2分离性能研究

The developing of high performance membrane for CO2 separation is critical for CO2 capture with low cost. In this proposal, the natural nanochannel for CO2 transport in facilitated transport membrane which contains fixed carriers will be designed for the CO2 permselectivity improvement. The Cu(I) catalyzed “click chemistry” will be employed in this proposal to prepared CO2 carriers functionalized polymers with “side-chain-type” architecture which will induce the nanophase separation of polymer membranes. And thus, high CO2 permeability will be achieved. Subsequently, the collaborative functionalized groups having weak hydrogen-bonding ability will be introduced into polymer for controlling the interaction of carriers. Finally, comb-shaped polymer will be designed and prepared by the introduction of the long side chain. As well as known, the comb-shaped polymeric architecture will induce well-defined phase separation, and thus well-connected nanochannel. These well-connected nanochannels contain CO2 carriers of amine groups, and thus will improve the CO2 transport. The membrane could be obtained by solution casting or coating on the polymer ultrafiltration. The effect of membrane fabrication condition, temperature and relative humidity on the CO2 separation performance will be investigated. Then, the relationship between chemical structures and CO2 separation performance will be further study for high performance membrane development. We believe that the proposed investigations will give us the insight for CO2 facilitated transport membrane with fixed carriers design and preparation.

发展高性能CO2分离膜是解决CO2低成本捕集的关键。本项目拟通过在分离CO2固定载体膜中引入自然形成的CO2传输纳米通道，提高CO2透过性及分离选择性，得到高性能CO2固定载体膜。采用高效、高选择性的“点击化学”合成方法，在高分子侧链中定量引入载体基团和调节载体相互作用的协同功能基团（例如-OH，酰胺等）；并适量在侧链中引入长梳状基团，形成具有梳状侧链的高分子链结构，调节高分子基团结构之间的亲疏水性，诱导发生微相分离，自然形成传输CO2的纳米通道。采用浇铸法或涂覆法制备膜，研究制膜条件、温度、相对湿度对膜中微相分离结构和综合性能的影响规律。建立自具纳米通道CO2固定载体膜材料的分子设计及制备方法，阐明微相分离纳米通道形成规律。揭示纳米通道微结构、官能团协同作用等对膜分离性能的影响规律，为设计、制备自具纳米通道固定载体膜提供理论依据和实验方法，获得高性能CO2分离膜。

发展高性能CO2分离膜是解决CO2低成本捕集和促进其走向工业应用的关键。本项目通过点击化学方法，制备了同时具有亲水促进传递基团和梳状侧链的分离CO2的固定载体高分子膜材料；利用膜材料中亲疏水基团性质差异，在膜中诱导形成具有微相分离结构的纳米通道，提高膜中CO2透过性及分离选择性，得到高性能CO2固定载体膜。基于此，本项目分别开展了如下几方面工作：1）采用商业化聚环氧氯丙烷为前驱体聚合物，通过叠氮化和点击化学反应制备了具有亲水胺基和疏水侧链的梳状高分子，考察了促进传递基团数量、协同基团类型、疏水侧链长短等对膜结构和膜性能的影响，发现亲疏水性质差异诱导形成的微相分离结构可明显增加膜的气体渗透性能，同时研究中也发现聚环氧氯丙烷在改性反应过程中分子量有所降解，亲疏水性的较大差异，导致部分制备的聚合物溶解性变差，为系统研究构效关系造成了一定困难，且此类膜不能自制备支撑仅可涂覆于超滤基膜上制备复合膜，因此其并非十分理想的前体聚合物。2）在前面基础上采用自制聚酰亚胺高分子为前驱体，通过点击化学接枝促进传递基团、并通过共同点击的方法，制备同时具有促进传递基团、协同基团和疏水侧链的聚合物。研究发现接枝促进传递基团后，聚酰亚胺选择性明显提升，协同基团对分散促进传递基团之间作用力具有积极作用，而疏水侧链与亲水性基团之间性质差异可诱导形成微相分离结构，同时这种接枝促进传递基团和梳状侧链的聚酰亚胺可同时提高气体选择性和渗透性，具有良好的应用前景。3）采用具有梳状侧链的高分子材料分别制备了均质膜、平板非对称膜和非对称中空纤维膜，研究了制膜条件及操作条件对膜气体分离性能的影响。在本项目支持下，在Journal of Membrane Science等期刊上发表论文2篇、申请发明专利6项，获得授权实用新型专利6项。