Abstract:The immersion deposition method is used to deposit nano-SiO2 on the surface of the membrane with the aid of the adhesion of PVDF in the immersion liquid. The self-assembly reaction between the silanol on the surface of SiO2 and the silanol hydrolyzed by octadecyltrimethoxysilane (OTMS) was used to prepare a superhydrophobic distillation membrane. The effects of PVDF content and SiO2 in the immersion liquid on the properties of the modified membrane were studied. When the content of PVDF is 0.3 wt% and SiO2 is 0.5 wt%, the performance of the membrane is the best. The SEM results show that the surface of the membrane is composed of PVDF microcrystals and nano-SiO2 to form a porous continuous rough structure with a contact angle of 156.5°. After 180 min of ultrasonic treatment and 48 h of strong alkali immersion, the surface of the membrane still has superhydrophobic properties. In the DCMD test of NaCl and SDS mixed solution, NaCl and HA mixed solution, the modified membrane has stable flux and rejection. Under the influence of pollutants SDS and HA, the flux and retention of the original membrane decreased, and the modified membrane had good anti-wetting and anti-fouling performance.