物理化学学报 >> 2015, Vol. 31 >> Issue (10): 1963-1970.doi: 10.3866/PKU.WHXB201508282

催化和表面科学 上一篇    下一篇

多孔材料表面修饰聚酰亚胺非对称混合基质膜对CO2/N2和CO2/CH4的气体分离

龚金华,王臣辉,卞子君,阳立,胡军*(),刘洪来   

  • 收稿日期:2015-06-12 发布日期:2015-10-10
  • 通讯作者: 胡军 E-mail:junhu@ecust.edu.cn
  • 基金资助:
    国家重点基础研究发展规划项目(973)(2013CB733501);国家自然科学基金项目(91334203, 21376074)

Asymmetric Polyimide Mixed Matrix Membranes with Porous Materials-Modified Surfaces for CO2/N2 and CO2/CH4 Separations

Jin-Hua. GONG,Chen-Hui. WANG,Zi-Jun. BIAN,Li. YANG,Jun. HU*(),Hong-Lai. LIU   

  • Received:2015-06-12 Published:2015-10-10
  • Contact: Jun. HU E-mail:junhu@ecust.edu.cn
  • Supported by:
    the National Key Basic Research Program of China (973)(2013CB733501);National Natural Science Foundationof China(91334203, 21376074)

摘要:

兼具高通量和高选择性的气体分离膜是研究膜分离材料的目标.采用相转化法制备了聚酰亚胺非对称膜,并将其作为基底膜材料,分别在其表面修饰掺有金属有机框架材料Cu3(BTC)2 (1, 3, 5-均苯三甲酸合铜),沸石咪唑酯骨架材料ZIF-8以及镁铝水滑石MgAl-LDHs的聚酰胺酸溶液,经热亚胺化后制成非对称混合基质膜.研究了该系列非对称混合基质膜的结构特性和对CO2、CH4和N2气体分离性能;考察了ZIF-8的掺杂量对非对称混合基质膜透气性能的影响.结果表明非对称聚酰亚胺膜的表面修饰可有效地改变膜的表面性质,掺杂ZIF-8的非对称混合基质膜气体的透气性能和选择性都增加,且掺杂量为5% (w)时CO2/N2和CO2/CH4的理想选择性分别高达24和83,为合成高效的CO2分离膜提供了借鉴.

关键词: 混合基质膜, 气体分离, 表面修饰, 聚酰亚胺, ZIF-8

Abstract:

Membranes with both good permeation and selectivity are highly desired for gas separations. We synthesized a polyimide (PI) asymmetric membrane using the phase-inversion method, and then modified the surface with a mixture of porous fillers and poly(amic acid) (PAA). The porous fillers included the metal organic framework (MOF) of Cu3(BTC)2 (copper benzene-1, 3, 5-tricarboxylate), the zeolite imidazole framework (ZIF) of ZIF-8, and the porous hydrotalcite of MgAl-LDH. A series of asymmetric mixed-matrix membranes (MMMs) were obtained after surface coating and thermal amidation. The MMM structure, CO2, CH4, and N2 permeance, and the ideal gas selectivity were investigated. With the surface modification, the morphology of the surface separation layers of the asymmetric PI/ZIF-8, PI/LDH, and PI/Cu3(BTC)2 MMMs significantly changed, and the gas separation performance changed accordingly. The PI/ZIF-8 asymmetric MMM with 5% (w) ZIF-8 doping exhibited both enhanced ideal gas selectivity and permeance; the CO2/N2 and CO2/CH4 selectivity were as high as 24 and 83, respectively. Thus, this surface modification provides improved MMM gas separation performance.

Key words: Mixed matrix membrane, Gas separation, Surface modification, Polyimide, ZIF-8

MSC2000: 

  • O646