Fabrication of porous β−cyclodextrin polymer mixed matrix membranes for benzotriazole removal from aqueous solution

Preparation of powdered materials into membrane is one of the effective means to address the susceptibility of nanopowder adsorbent materials to loss. In this study, we first explored the potential of porous β−cyclodetrin polymer (P−CDP) powders in the removal of benzotraizole (BTA), and found that P−CDP powders have high efficiency in removing BTA, and the mechanism of BTA removal on P−CDP powders was investigated, in which the ionic C−F bonding of P−CDP powders and N−H bonding of BTA chemical combination and create a new covalent N−F bonding. Furthermore, the π-π interactions and hydrogen bonds also played an important role on BTA molecules. In order to solve the problems that powdered materials are not easy to recycle and easy to cause secondary pollution of water bodies, a innovative adsorptive mixed matrix membranes were prepared via integration P−CDP powders into polyacrylonitrile (PAN) membranes. The P−CDP/PAN mixed matrix membranes were fabricated by a simple phase inversion strategy. The physicochemical properties of the obtained membranes were characterized and the different loading rates of P−CDP powders were compared. Experimental results showed that the optimal P−CDP/PAN membranes had the fastest saturation time for BTA adsorption (10 min) and the highest BTA adsorption capacity of 337 mg·g⁻¹. Meanwhile, the P−CDP/PAN membranes exhibited the hydrophilic nature with a high water permeance of 83 L·m⁻²·h⁻¹·bar⁻¹. In addition, the optimal P−CDP/PAN membranes displayed promising application in dynamic system for removing BTA. Moreover, the P−CDP/PAN membranes demonstrated outstanding regeneration efficiency and reusability over multiple cycles, coupled with simplified post-treatment procedures for phase separation compared to conventional powdered adsorbents. This study provides a novel strategy in fabricating adsorptive membranes for emerging organic contaminants removal.