高等学校化学学报

高等学校化学学报

• 研究论文 • 上一篇    下一篇

二次界面聚合法制备高锂镁分离性能电纳滤膜

刘慧莉1,2，汪  婧1,2，陈加帅1,2，宋治昊1,2，蒋雨萌1,2，郭志远1,2，张盼盼1,2，纪志永1,2   

  1. 1. 河北工业大学化工学院/海水资源高效利用化工技术教育部工程研究中心，天津  300401；
    2. 河北省现代海洋化工技术协同创新中心，天津  300401
  • 收稿日期:2023-11-22 修回日期:2024-03-25 网络首发:2024-04-12 发布日期:2024-04-12
  • 通讯作者: 汪婧 E-mail:wangjing1989@hebut.edu.cn
  • 基金资助:
    国家自然科学基金（批准号：22108057）和河北省重点研发计划项目基金（批准号：21373101D）资助.

Preparation of Electro-nanofiltration Membranes with High Li+/Mg2+ Separation Performance via Sequential Interfacial Polymerization

LIU Huili1,2, WANG Jing1,2, CHEN Jiashuai1,2, SONG Zhihao1,2, JIANG Yumeng1,2,GUO Zhiyuan1,2, ZHANG Panpan1,2, JI Zhiyong1,2   

  1. 1. Engineering Research Center of Seawater Utilization Technology of Ministry of Education, School of Chemical Engineering and Technology, Hebei University of Technology, Tianjin 300401, China;
    2. Hebei Collaborative Innovation Center of Modern Marine Chemical Technology, Tianjin 300401, China
  • Received:2023-11-22 Revised:2024-03-25 Online First:2024-04-12 Published:2024-04-12
  • Contact: Jing WANG E-mail:wangjing1989@hebut.edu.cn
  • Supported by:
    Supported by the National Natural Science Foundation of China(No.22108057) and Hebei Province Key R&D Program Project Fund, China
    (No.22108057).

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摘要： 调控界面聚合水相单体并利用二次界面聚合(SIP)构建荷正电表面，以制备高选择性电纳滤膜(ENFMs)用于选择性电渗析过程分离锂镁。采用不同水相单体与均苯三甲酰氯进行单次界面聚合(IP)，实现了对分离膜孔径及荷电性能的调控，且以哌嗪为水相单体时膜的Li+/Mg2+分离性能最优(4.75)。随后，利用SIP过程在其表面聚合不同浓度的荷正电水相单体聚乙烯亚胺(PEI，M.W. =70 kDa)，将膜面由荷负电转为荷正电。随着PEI浓度的增加，膜表面正电荷密度显著增加，PEI浓度为2 wt%时，最优膜的Li+通量为3.26×10-8 mol·cm-2·s-1，选择性高达15.9，打破了传统的“Trade-off”效应，为后续盐湖卤水中Li+/Mg2+分离的研究和应用奠定了基础。

关键词: 界面聚合, 电纳滤膜, 选择性电渗析, Li+/Mg2+分离

Abstract: Highly selective electro-nanofiltration membranes (ENFMs) were prepared by regulating the aqueous-phase monomers of interfacial polymerization (IP) and constructing the positively charged surface by sequential interfacial polymerization (SIP) for the separation of lithium and magnesium by selective electrodialysis processes. The IP reaction was carried out using different aqueous-phase monomers with trimesoyl chloride to achieve the regulation of the pore size and charging property of the separation membranes. The optimum Li+/Mg2+ separation performance (4.75) of the membrane was achieved when piperazine was used as the aqueous-phase monomer. Subsequently, the SIP reaction was utilized to introduce positively charged aqueous-phase monomer polyethyleneimine (PEI, M.W. =70 kDa) of different concentrations on the optimal IP membrane surface, which converted the charge of the membrane surface from negative to positive. With the increase of PEI concentration, the positive charge density on the membrane surface increased significantly; the optimal SIP membrane achieved outstanding selectivity for Li+/Mg2+ (15.9) and high Li+ flux (3.26 × 10-8 mol·cm-2·s-1), which breaks the traditional “Trade-off” effect and lays the foundation for the subsequent research and application of Li+/Mg2+ separation salt-lake brines.

Key words: Interfacial polymerization, Electro-nanofiltration membrane, Selective electrodialysis, Li+/Mg2+ separation

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