ZIF-8改性自具微孔聚合物膜的制备及其对CO_(2)的分离性能  

Preparation of polymer membrane with intrinsic microporosity modified by ZIF-8 and its separation performance for CO_(2)

作　　者：赵红永[1,2] 赵晨阳 丁晓莉[4] 张永刚[3] ZHAO Hongyong;ZHAO Chenyang;DING Xiaoli;ZHANG Yonggang(State Key Laboratory of Separation Membranes and Membrane Processes,Tiangong University,Tianjin 300387,China;School of Chemical Engineering and Technology,Tiangong University,Tianjin 300387,China;School of Environme-ntal Science and Engineering,Tiangong University,Tianjin 300387,China;School of Material Science and Engineering,Tiangong University,Tianjin 300387,China)

机构地区：[1]天津工业大学省部共建分离膜与膜过程国家重点实验室,天津300387 [2]天津工业大学化学工程与技术学院,天津300387 [3]天津工业大学环境科学与工程学院,天津300387 [4]天津工业大学材料科学与工程学院,天津300387

出　　处：《天津工业大学学报》2024年第4期1-6,共6页Journal of Tiangong University

基　　金：国家自然科学基金资助项目(21776217,21978214)。

摘　　要：为了提高自具微孔聚合物(PIMs)膜对CO_(2)的分离效果,对PIM-1膜进行功能化改性。首先,将PIM-1膜通过水解、置换等作用引入Zn2+离子,再将改性后的PIM-1膜浸泡在2-甲基咪唑的甲醇溶液中,于室温下在膜表面生长类沸石咪唑酯框架-8(ZIF-8)选择层,经过硅橡胶填补后得到无缺陷ZIF-8改性PIM-1膜(pZIF-8@PIM-1),并对其性能和结构进行测试和表征。结果表明:在离子改性后的PIM-1膜表面成功生长了厚度约0.8μm的ZIF-8选择层,晶体尺寸大小均匀,粒径直径在200 nm左右;与PIM-1纯膜相比,由于多价金属离子交联及ZIF-8选择层的存在,pZIF-8@PIM-1的CO_(2)扩散系数明显下降,CO_(2)/N_(2)扩散选择性有所上升,由0.89提升到1.01;ZIF-8中含氮有机杂环与CO_(2)之间的Lewis酸碱作用及2-甲基咪唑环上静电势对CO_(2)的亲和作用,使得pZIF-8@PIM-1的CO_(2)溶解度系数上升,且CO_(2)/N_(2)溶解选择性也得到提升,由18.56提升到20.31;改性后的PIM-1膜CO_(2)/N_(2)扩散选择性及CO_(2)/N_(2)溶解度选择性的双重提升共同促进了CO_(2)/N_(2)分离系数的提升,由原膜的16.57增加到20.43,具有良好的CO_(2)分离性能。In order to improve the CO_(2) separation of intrinsic microporosity(PIMs)membrane of polymers,the PIM-1 membr-ane was functionally modified.First,the PIM-1 membrane was introduced Zn2+was introduced into the PIM-1 membrane by alkaline hydrolysis and replacement,and then the modified PIM-1 membrane was immersed in a methanol solution of 2-methylimidazole to grow zeolitic imidazolate framework-8(ZIF-8)selective layer on the membrane surface at room temperature.The defect-free ZIF-8 modified PIM-1 membrane(pZIF-8@PIM-1)was obtained after silicone rubber filling.The performance and structure were tested and characterized.The results showed that the ZIF-8 selective layer with a thickness of about 0.8μm was successfully grown on the surface of the ion-modified PIM-1 membrane,and the crystal size was uniform with a particle size of about 200 nm.Compared with the PIM-1 membrane,the CO_(2) diffusion coefficient of pZIF-8@PIM-1 decreased significantly and the CO_(2)/N_(2) diffusivity selectivity increased from 0.89 to 1.01 due to the cross-linking of multivalent metal ions and the presence of ZIF-8 selective layer.The Lewis acid-base interaction between the nitrogen-containing organic heterocyclic ring of ZIF-8 and CO_(2) and the affinity of the electrostatic potential on the 2-methylimidazole ring for CO_(2) led to the increase of the CO_(2) solubility coefficient of pZIF-8@PIM-1 and the improvement of the CO_(2)/N_(2) solubility selectivity from 18.56 to 20.31.The dual improvement of CO_(2)/N_(2) diffusivity selectivity and CO_(2)/N_(2) solubility selectivity of the modified PIM-1 membrane jointly promoted the improvement of CO_(2)/N_(2) selectivity from 16.57 to 20.43,with good CO_(2) separation performance.

关 键 词：气体分离膜 自具微孔聚合物 类沸石咪唑酯框架-8(ZIF-8) CO_(2)分离 

分 类 号：TQ028.1[化学工程]