Preparation and Performance of Surface Modified PTFE Hollow Fiber Membranes by Self-Polymerization of Dopamine

Surface modification of polytetrafluoroethylene(PTFE) hollow fiber membranes was performed via self-polymerization of dopamine. Properties such as surface morphology, chemical composition and hydrophilicity of the PTFE membranes before and after modification were characterized by scanning electron microscope(SEM), X-ray photoelectronic spectroscopy(XPS), Fourier transform infrared spectroscopy(FT-IR) and contact angle(CA), and the effect of modification conditions on pure water flux was investigated. Moreover, the antifouling property of the unmodified and modified membranes was also studied by using bovine serum albumin(BSA) as a model pollutant. The results indicate that dopamine can be successfully introduced onto PTFE membrane surface and the fluorine content on membrane surface decreases by 2.14% and the oxygen content increases by 3.06% after hydrophilic modification for 12 h. The hydrophilicity of PTFE is significantly improved with water contact angle decreased from 110° to 80° after modification. The water flux of the modified membrane is 1.5 times of the original ones after 8 h modification. The membrane pores are not affected after modification and the modified membranes exhibit better antifouling performance. The flux recovery rate is over 90% after water cleaning.