CIESC Journal ›› 2023, Vol. 74 ›› Issue (4): 1598-1606.DOI: 10.11949/0438-1157.20230091

• Separation engineering • Previous Articles     Next Articles

Triazine framework polymer membranes for methanol/n-hexane separation via organic solvent nanofiltration

Yangguang LYU(), Peipei ZUO, Zhengjin YANG(), Tongwen XU()   

  1. School of Chemistry and Materials Science, University of Science and Technology of China, Hefei 230026, Anhui, China
  • Received:2023-02-20 Revised:2023-03-20 Online:2023-06-02 Published:2023-04-05
  • Contact: Zhengjin YANG, Tongwen XU

三嗪框架聚合物膜用于有机纳滤甲醇/正己烷分离

吕阳光(), 左培培, 杨正金(), 徐铜文()   

  1. 中国科学技术大学化学与材料科学学院,安徽 合肥 230026
  • 通讯作者: 杨正金,徐铜文
  • 作者简介:吕阳光(1996—),男,硕士研究生,yglv@mail.ustc.edu.cn
  • 基金资助:
    国家自然科学基金项目(21922510)

Abstract:

Microporous polymer membranes resistant to various organic solvents have gradually attracted attention in the field of organic nanofiltration. Herein, we report a covalent triazine framework membrane (CTF-BP) synthesized by a super acid-catalyzed organo-sol-gel reaction of commercially available aromatic nitrile monomer. This membrane exhibits good mechanical strength and is dimensionally stable in organic solvents, such as methanol, n-hexane, etc. Size sieving by the robust micropores (<1.0 nm) confers the membrane with a cut-off molecular weight as low as 550. The hydrogen interaction between triazine rings and the hydroxyl groups facilitates the transport of methanol, the flux of which reaches up to 1.10 L/(m2·h·bar), a value much higher than that of the less viscous n-hexane [0.23 L/(m2·h·bar)]. To demonstrate the practical applicability, this membrane is utilized to separate n-hexane containing low concentration of methanol solution [5% (mass) methanol], and a maximum separation factor of 1485 and a methanol flux of 3.21 kg/(m2·h) are obtained. These results demonstrate the great potential of the CTF-BP membranes in the recovery of methanol from its mixture with n-hexane via organic solvent nanofiltration (OSN).

Key words: covalent triazine framework, polymer membrane, organic solvent resistant, nanofiltration, methanol/ n-hexane separation

摘要:

具备耐各种有机溶剂的微孔聚合物膜在有机纳滤领域逐渐受到重视。采用双氰基单体的超酸催化成环聚合反应,制备微孔框架聚合物薄膜(CTF-BP),该膜具备良好的力学性能,可耐受甲醇和正己烷等常见有机溶剂。CTF-BP膜内大量<1.0 nm的微孔通道使膜具备良好的筛分性能,其截留分子量为550。膜内含有的三嗪结构与羟基具有较强的亲和性,使甲醇的跨膜通量[1.10 L/(m2·h·bar)]显著高于黏度更低的正己烷通量[0.23 L/(m2·h·bar)]。采用纳滤操作将膜用于分离含低浓度甲醇的正己烷溶液[含5%(质量)甲醇的正己烷溶液],结果显示甲醇/正己烷分离因子最高可达到1485,渗透液的总流量超过3.21 kg/(m2·h)。证实CTF-BP膜有望实现高效甲醇/正己烷分离。

关键词: 三嗪框架, 聚合物膜, 耐有机溶剂, 纳滤, 甲醇/正己烷分离

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