TiO 2 Nanorod Entrapped Coaxially Dry Jet Wet Spun PVDF Hollow Fiber Membranes for E. coli Contaminated–Water Purification Applications

ABSTRACT Although titanium dioxide (TiO 2 ) nanoparticles (NPs) are biocompatible and have antibacterial properties, they can leak from polymer‐based nanocomposite membranes into filtered water because of their small size and isotropic shape. To address this, this study explores the use of anisotropic TiO 2 nanomaterials, including high‐aspect‐ratio nanowires (NWs) and low‐aspect‐ratio nanorods (NRs), synthesized through scalable alkaline hydrothermal reaction and rapid ultrasonic fragmentation. These nanomaterials were entrapped on the effective filtration surface of polyvinylidene fluoride (PVDF) hollow fiber membranes (HFMs) during an industrial coaxial dry jet wet spinning process to limit leakage. The performance of the membranes in removing E. coli was evaluated using optical density (OD), MTT assays, and colony‐forming unit (CFU) counts in a crossflow filtration setup with a UVA light source. The HFM entrapped with TiO 2 NRs demonstrated a pure water flux (PWF) of 68.7 L m −2 h −1 , an 84.9% rejection of bovine serum albumin (BSA), and a 97.3% removal of live E. coli bacteria. Notably, TiO 2 nanomaterial leakage was only 1.9 ppm, well below the 120 ppm toxicity threshold.