Antifouling and antibacterial PES ultrafiltration membranes fabricated using an unmodified 3D printer-assisted casting platform

In this study, the fabrication of ultrafiltration membranes is reported through the innovative use of a commercial, unmodified 3D printer, which was utilized not as a printing tool but as a precisely controlled motion and temperature platform. This approach offers a novel, cost-effective, and reproducible alternative to conventional production methods, enabling improved control over fabrication parameters and enhanced reproducibility compared to conventional manual casting methods. Fabrication parameters were systematically optimized, initially by varying the casting temperature (30, 60, and 90 °C) at a fixed speed, and subsequently by modulating the casting speed (32.5, 65, 97.5, and 130 mm s−1) at the predetermined optimal temperature. To impart antifouling and antibacterial functionality, a custom-synthesized N-halamine-based polymer was incorporated into the optimized casting solution to create N-halamine-modified membranes. The resulting membranes exhibited thicknesses ranging from 103 to 152 µm, with pure water flux values between 60 and 239 L m−2 h−1 and bovine serum albumin rejection rates consistently exceeding 90%. Notably, the N-halamine-modified membrane demonstrated a flux recovery ratio of approximately 109% after chemical washing, significantly surpassing the ~ 73% flux recovery ratio of its unmodified counterpart. Furthermore, the antibacterial assays demonstrated that the chlorinated, modified membrane effectively inactivated both Staphylococcus aureus and Escherichia coli within 15 min (> 5-log reduction), whereas the control membranes showed no significant antibacterial activity. In addition, porosity and pore size analyses confirmed that the membrane structure was preserved after modification and chemical cleaning, while long-term stability tests indicated stable immobilization of the N-halamine polymer within the membrane matrix. These findings establish a 3D printer-assisted casting approach as a feasible strategy for membrane fabrication and highlight N-halamine incorporation for creating membranes with enhanced and regenerable antifouling and antibacterial performance.