Covalent organic framework functionalized smart membranes with under-liquid dual superlyophobicity for efficient separation of oil/water emulsions

Yaqi Zhang; Shiwei Tian; Qiankun Sha; Jinjie Lv; Na Han; Xingxiang Zhang

doi:10.1016/j.scitotenv.2023.166895

Covalent organic framework functionalized smart membranes with under-liquid dual superlyophobicity for efficient separation of oil/water emulsions

Sci Total Environ. 2023 Dec 15:904:166895. doi: 10.1016/j.scitotenv.2023.166895. Epub 2023 Sep 6.

Authors

Yaqi Zhang¹, Shiwei Tian¹, Qiankun Sha², Jinjie Lv¹, Na Han³, Xingxiang Zhang⁴

Affiliations

¹ State Key Laboratory of Separation Membranes and Membrane Processes, Tianjin 300387, China; Tianjin Municipal Key Laboratory of Advanced Fiber and Energy Storage Technology, School of Materials Science and Engineering, Tiangong University, Tianjin 300387, China.
² National Innovation Center of Advanced Dyeing & Finishing Technology, Tai'an, Shandong 271000, China.
³ State Key Laboratory of Separation Membranes and Membrane Processes, Tianjin 300387, China; Tianjin Municipal Key Laboratory of Advanced Fiber and Energy Storage Technology, School of Materials Science and Engineering, Tiangong University, Tianjin 300387, China. Electronic address: hanna@tiangong.edu.cn.
⁴ State Key Laboratory of Separation Membranes and Membrane Processes, Tianjin 300387, China; Tianjin Municipal Key Laboratory of Advanced Fiber and Energy Storage Technology, School of Materials Science and Engineering, Tiangong University, Tianjin 300387, China. Electronic address: zhangtjpu@hotmail.com.

PMID: 37683856
DOI: 10.1016/j.scitotenv.2023.166895

Abstract

The smart membrane with under-liquid dual superlyophobicity, which can achieve on-demand separation of oil/water emulsions only by simple liquid pre-wetting, is of essential value for the treatment of complicated real oil/water systems. Here, we first fabricated a stable suspension of imine-linked covalent organic framework nanospheres (TPB-DMTP-COF), and subsequently fabricated COF functionalized smart membranes with under-liquid dual superlyophobicity by immersing polyacrylonitrile-based (PAN-based) membranes into TPB-DMTP-COF nanosphere suspension. Accordingly, effective switchable separation of both oil-in-water and water-in-oil emulsions by TPB-DMTP-COF/PAN membranes can be achieved by employing pre-wetting processes (both the oil contact angle under water and the water contact angle under oil are over 150°). Specifically, the separation flux and the separation efficiency are higher than 1200 L/m²‧h and 98.0 %, and 2100 L/m²‧h and 97.4 % for the surfactant-stabilized oil-in-water and water-in-oil emulsions, respectively. Furthermore, the ultralow adhesions in liquid contributed to the outstanding reusability and antifouling resistance of the prepared TPB-DMTP-COF/PAN membranes. This work provides a feasible approach for fabricating a smart membrane with under-liquid dual superlyophobicity for oily wastewater treatment.

Keywords: Covalent organic framework; Oil/water separation; Smart membrane; Under-liquid dual superlyophobicity.