Effect of coagulation bath and amphiphobic modification on the structure and membrane distillation properties of polyvinylidene fluoride membrane

<p indent="0mm">Membrane distillation (MD) technology has a wide prospect in the field of high salt wastewater treatment. How to obtain high performance MD membranes is the focus of research. In this paper, PVDF pristine membranes were prepared by nonsolvent-thermally induced phase separation (NTIPS). The effects of different coagulation baths (namely, ethanol,glycerol and their mixtures) on the structure and MD properties of PVDF pristine membranes were investigated. The water flux and salt rejection of MD, anti-wetting, and anti-fouling properties of the amphiphobic membrane modified by 1<italic>H</italic>,1<italic>H</italic>,2<italic>H</italic>,2<italic>H</italic>-perfluorodecyltriethoxysilane were further investigated. The results show that the structure of the pristine membrane can be changed from finger-like to spongy-like pores structure by tuning the coagulation conditions. The PVDF amphiphobic membrane has excellent anti-wetting and anti-fouling properties when treated with simulated feed containing salt, surfactant, oil or humic acid. This study provides a feasible route not only for controlling the pore structure of PVDF membrane via the NTIPS process, but also a viable method for amphiphobic modification method of PVDF membrane.