Abstract:

It is a very effective strategy to prepare mixed matrix membranes (MMM) by incorporating hydrophobic nanoparticle into the polymer matrix to improve the pervaporation separation performance in the process of recovering ethanol from aqueous solution. In this study, polydimethylsiloxane (PDMS) based MMM filled with ZIF-67 particles was prepared on ceramic tubes, but there were some associated problems such as severe reunion, poor compatibility, etc. In order to improve the diffusion process, ZIF-67-derived nanoporous carbon (C-ZIF-67) was prepared to replace ZIF-67 in conventional MMM.ZIF-67 and carbonized particles were studied by various characterization, and the morphology and properties of MMMs were tested. Compared with ZIF-67/PDMS MMM and pure PDMS membrane, C-ZIF-67/PDMS MMM exhibited better enhanced separation performance: the best performance with a total flux of 1.04kg/(m²·h) and a separation factor of 9.2 at 60℃ for 5% ethanol solution. In summary, the relevant experimental results had preliminarily indicated that C-ZIF-67/PDMS MMM had potential application value in the separation of dilute ethanol aqueous solution.

Key words: ZIF-67-derived nanoporous carbon, polydimethysiloxane, membranes, tubular ceramic support, pervaporation

摘要：

在聚合物基体中加入疏水性纳米多孔填料制备混合基质膜（MMM），是提高低浓度乙醇水溶液渗透汽化分离性能十分有效的策略。本文为适应工业化应用要求，在管式陶瓷载体上制备了ZIF-67颗粒填充的聚二甲基硅氧烷（PDMS）基MMM，但存在ZIF-67颗粒在基质膜中出现一定程度的团聚导致分散性不好、ZIF-67与基质膜之间的界面相溶性不理想等不足。进而进一步制备了ZIF-67衍生纳米多孔碳（C-ZIF-67），以取代传统MMM中的ZIF-67。通过各种表征研究了ZIF-67及其碳化颗粒的化学结构，并对所得MMMs的形态和性质进行了测试。由于碳成分固有的强疏水性质、相对较好的分散性以及与PDMS更好的相溶性，C-ZIF-67/PDMS MMM表现出比ZIF-67/PDMS MMM和纯PDMS膜更优异的分离性能。在60℃下质量分数5%的乙醇水溶液中，C-ZIF-67/PDMS-15% MMM的性能最佳，通量为1.04kg/(m²·h)，相应的分离因子为9.2。综合来看，相关实验结果已初步表明C-ZIF-67/PDMS MMM在低浓度乙醇水溶液分离中具有潜在的应用价值。

关键词: ZIF-67衍生的纳米多孔碳, 聚二甲基硅氧烷, 膜, 管式陶瓷载体, 渗透蒸发