Enhancing antibacterial performances of PVDF hollow fibers by embedding Ag-loaded zeolites on the membrane outer layer via co-extruding technique

Ag-loaded zeolites were synthesized and embedded into the outer layer of poly(vinylidene fluoride) (PVDF) dual-layer hollow fiber membrane (D) using a dry-jet wet-spinning co-extruding technique. The distribution of the Ag-loaded zeolites in the outer layer was confirmed by field emission scanning electron microscopy (FE-SEM) and energy-dispersive X-ray spectroscopy (EDX). It was found that the D contained only 54% of the amount of Ag-loaded zeolites that were distributed throughout the cross section of PVDF single-layer hollow fiber membrane (S), as calculated by thermogravimetric analysis (TGA). However, D showed excellent antibacterial efficiency and resistance to bacterial adhesion because of the higher concentration of Ag+ in the outer layer of the membrane. The surface morphologies, pure water flux, mean pore size, pore size distribution, and thermal stability of both PVDF membranes were also investigated.