Robust covalent organic frameworks membranes for ultrafast dye/salt separation in harsh environments

• Published in: Desalination Vol. 568; p. 117025
• Main Authors: Dai, Jia-Yue, Fang, Yin-Xin, Xu, Zhen-Liang, Pandaya, Dibakar, Liang, Jing, Yan, Hong-Fei, Tang, Yong-Jian
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.12.2023
• Subjects: Covalent organic frameworks; Hydrazone-linked; Interfacial catalytic polymerization; Nanofiltration; β-Ketoenamine; Covalent organic frameworks; β-Ketoenamine; Hydrazone-linked; Nanofiltration; Interfacial catalytic polymerization
• ISSN: 0011-9164; 1873-4464
• DOI: 10.1016/j.desal.2023.117025

Although covalent organic frameworks (COFs) membranes have promising applications in water treatment due to their ordered structure and adjustable pore size, most of them are imine-linked ones, which severely limits their application in harsh environments. Herein, we offer a stable novel COFs membrane which is composed of hydrazone bonds and β-ketoenamine structures. Such β-ketoenamine based COFs composite membrane was fabricated via interfacial catalytic polymerization on a nylon substrate, which was generated at the water (P-Toluenesulfonic acid)/n-hexane (2,5-dimethoxyterephthalhydrazide, 1,3,5-triformylphoroglucinol) interface. The resultant COFs membrane demonstrates excellent chemical stability in strong acidic (2 mol/L)/alkaline (9 mol/L)/organic solvents (dioxane, acetone, methanol, and ethanol) media. The optimized COFs membrane achieved 109.73 L m−2 h−1 bar−1 permeance in Congo Red aqueous solution and 99.56 % CR rejection. This study exploits a novel approach to produce robust COFs membranes under extreme conditions. [Display omitted] •TpDMTH COFs membranes were fabricated via interfacial catalytic polymerization.•The combination of hydrazone bonds and β-ketoenamine structures makes membranes show stable chemical structure.•Such COFs membranes maintained excellent separation performance in 9 M NaOH solution.•Such COFs membranes showed excellent dye/salt separation performance.