Metal coordinated PAN hollow fiber membranes with triaxial cross-linked structure and its self-cleaning performance

To explore a kind of triaxial cross-linked hollow fiber membrane (HFM) with self-cleaning performance, polyacrylonitrile based HFM which was prepared by wet processing was chemically modified into amidoximated PAN hollow fiber membranes. Then the active groups were coordinated with metal ions (Fe³⁺) randomly to achieve metal coordinated amidoximation PAN hollow fiber membranes with triaxial cross-linked structure. Preparation process, structural composition, surface morphology, hydrophilic and hydrophobic properties, membrane flux and retention, self-cleaning performance of the hollow fiber membranes were studied. Results show that the amidoximation rate of the membranes increases with the rise of time, temperature and hydroxylamine hydrochloride concentration during the modification process, and the modification levels would affect the crystallinity of the hollow fiber membranes so as to enhance the adsorption of small molecules into the fiber material. Although the Fe ions on the membranes would impact their crystal structure, hydrophilic property and membrane flux, but the triaxial cross-linked structure would promote the retention performance for bovine serum albumin to 88%. Besides, Fenton catalytic system coupled by Fe(III) and H₂O₂ endows FePAN-HFM with antifouling and self-cleaning properties and the flux recovery rate reaches to 84.6% significantly.