One-step entrapment of a PS-PEGMA amphiphilic copolymer on the outer surface of a hollow fiber membrane via TIPS process using triple-orifice spinneret

A robust hydrophobic membrane modification method is required to avoid fouling that significantly affects membrane separation performance and energy consumption. In this study, we developed a one-step surface entrapment of an amphiphilic copolymer onto a poly(vinylidene fluoride) (PVDF) hollow fiber membrane (HFM) surface prepared via a thermally induced phase separation (TIPS) method. By extruding a poly(styrene)-b-poly (ethylene glycol) methacrylate (PS-PEGMA) solution at the outermost layer of a triple-orifice spinneret, entrapment of the amphiphilic copolymer onto the PVDF HFM was performed. The results showed that the preparation conditions significantly altered the membrane surface hydrophilicity without changing the bulk structure of the membrane. A longer air-gap distance, lower polymer concentration in the polymer solution, and higher PS-PEGMA concentration are favorable for better copolymer entrapment at the membrane surface. By comparing the water contact angle and BSA adhesion obtained using the proposed method and that achieved by the conventional coating process of the PS-PEGMA, it can be concluded that our one-step modification method is more robust and reliable.

Automated summary

A powerful hydrophobic membrane modification method was developed in this study, which involves surface entrapment of an amphiphilic copolymer onto a PVDF hollow fiber membrane prepared through a thermally induced phase separation method. The preparation conditions significantly affected the membrane surface hydrophilicity, with longer air-gap distance, lower polymer concentration, and higher PS-PEGMA concentration favoring better copolymer entrapment. The one-step modification method was found to be more robust and reliable compared to conventional coating processes.