Fouling-resistant and adhesion-resistant surface modification of dual layer PVDF hollow fiber membrane by dopamine and quaternary polyethyleneimine

• An effective process was developed to modify dual layer PVDF hollow fiber membranes.
• The modified membrane exhibited outstanding hydrophilicity and water flux.
• The modified membrane exhibited excellent bacterial killing and antiadhesion property.
• The newly-developed and universal modification was simple and easy to be done.

Poly(vinylidene fluoride) (PVDF) dual layer hollow fiber membrane was modified by coating dopamine and grafting polyethyleneimine, then the hydrophilic and antibacterial PVDF membrane was obtained through quaternization reactions. The attenuated total reflectant Fourier transform infrared spectra (ATR-FTIR) and X-ray photoelectron spectroscopy (XPS) were applied to confirm the successful modification. The water contact angle measurement suggested that the membrane hydrophilicity was significantly improved. Morphological changes of membranes were characterized by field emission scanning electron microscope (FE-SEM). The pure water flux before and after BSA contamination was measured and the flux recovery rate for the modified membrane was as high as 94%. The antibacterial tests showed that the hydrophilic and antibacterial PVDF membrane owned excellent anti-bacterial efficiency and resistance to bacterial adhesion. The average pore size, mechanical property and zeta potential were also investigated. All the results demonstrated this facile method can enhance the hydrophilicity and antibacterial ability of PVDF dual layer hollow fiber membrane, and would have application in water treatment.