化工学报 ›› 2022, Vol. 73 ›› Issue (9): 3904-3914.DOI: 10.11949/0438-1157.20220627

• 分离工程 • 上一篇    下一篇

碳纳米管/环糊精金属有机骨架协同强化混合基质膜的CO2分离

裴仁花1(), 王永洪1,2, 张新儒1,2(), 李晋平1,2   

  1. 1.太原理工大学化学工程与技术学院,山西 太原 030024
    2.气体能源高效清洁利用山西省重点实验室,山西 太原 030024
  • 收稿日期:2022-05-05 修回日期:2022-06-27 出版日期:2022-09-05 发布日期:2022-10-09
  • 通讯作者: 张新儒
  • 作者简介:裴仁花(1998—),女,硕士研究生,peirenhua2@163.com
  • 基金资助:
    国家自然科学基金面上项目(22078216);山西省自然科学基金面上项目(20210302123196);山西省回国留学人员科研资助项目(2021-056)

Synergistic of carbon nanotube/cyclodextrin metal organic framework for enhancing CO2 separation of mixed matrix membranes

Renhua PEI1(), Yonghong WANG1,2, Xinru ZHANG1,2(), Jinping LI1,2   

  1. 1.College of Chemical Engineering and Technology, Taiyuan University of Technology, Taiyuan 030024, Shanxi, China
    2.Shanxi Key Laboratory of Gas Energy Efficient and Clean Utilization, Taiyuan 030024, Shanxi, China
  • Received:2022-05-05 Revised:2022-06-27 Online:2022-09-05 Published:2022-10-09
  • Contact: Xinru ZHANG

摘要:

为了实现混合基质膜中CO2的高效分离,设计了羧基化多壁碳纳米管(CNT)和氨基化β-环糊精金属有机骨架(β-CD MOF)双填料(CM),并将其引入磺化聚醚醚酮(SPEEK)基质中,在膜内同时构建CO2扩散通道和亲和位点,增强了混合基质膜的分离性能。采用FTIR和BET表征了CM的化学结构和孔结构,借助膜的SEM、FTIR和力学性能表征了填料-聚合物界面相互作用。研究了CM的合成比例、含量、压力、温度和混合气等因素对混合基质膜分离性能的影响。结果表明:CM与SPEEK之间具有良好的相容性并为气体分子提供了快速的传递通道。在改性CNT与MOF的质量比为5∶5、添加量为7%(质量)以及0.1 MPa和25℃的条件下,混合基质膜的分离性能最优,CO2渗透性为844 Barrer,CO2/N2选择性为84,与纯SPEEK膜相比,分别提升了178%和163%,超过2019年上限。羧基化CNT的直孔通道缩短了CO2的扩散路径,同时改性β-CD MOF表面的氨基载体提升了CO2的溶解性,两者协同提高了混合基质膜的分离性能。此外,负载双填料的膜比单独负载相同含量的羧基化CNT或氨基化MOF的膜具有更好的分离性能。在360 h的测试过程中,混合基质膜保持较好的分离稳定性。

关键词: 混合基质膜, 磺化聚醚醚酮, β-环糊精金属有机骨架, 碳纳米管, CO2/N2分离

Abstract:

To achieve the CO2 efficient separation in mixed matrix membranes (MMMs), a dual-filler (CM) of carboxyl modified multi-walled carbon nanotubes (CNT) and amino modified β-cyclodextrin metal organic framework (β-CD MOF) was designed and introduced to sulfonated poly(ether ether ketone) (SPEEK) to construct both CO2 diffusion channels and affinity sites within the membranes, which enhanced the separation performance of MMMs. The chemical and pore structures of the dual-filler were characterized by FTIR and BET, and the filler-polymer interfacial interactions were verified by SEM, FTIR and mechanical properties of the membranes. The effects of the proportion, content, pressure, temperature and mixed gas on the separation performance of MMMs were investigated. The results showed that CM was compatible with SPEEK and provided fast transport channels for gas molecules. The SPEEK/CM-7 MMMs with mass ratio of 5∶5 displayed the optimal separation performance with a CO2 permeability of 844 Barrer and a CO2/N2 selectivity of 84 at 0.1 MPa and 25℃, which were 178% and 163% higher than those of the pristine SPEEK membrane, respectively, surpassing the 2019 upper bound. The straight pore channels of functional CNT shortened the CO2 diffusion path, while the amino carriers on the surface of modified MOF enhanced the CO2 dissolution, which synergistically improved the separation performance of MMMs. Moreover, the membranes loaded with dual-filler had preferable separation performance than those loaded with the same amount of carboxyl modified CNT or amino modified MOF alone. During 360 h testing, the SPEEK/CM-7 MMMs remained good stability.

Key words: mixed matrix membrane, sulfonated poly(ether ether ketone), β-cyclodextrin metal organic framework, carbon nanotube, CO2/N2 separation

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