Enhanced performance of superhydrophobic polypropylene membrane with modified antifouling surface for high salinity water treatment

In this work, the superhydrophobic polypropylene (PP) composite membranes with modified surface were successfully fabricated by loading the SiO2 nanoparticles and attaching low surface energy 1H,1H,2H,2H-perfluorodecyltriethoxysilane. The impact of deposited nanoparticle size on the surface roughness, heterogeneous nucleation barrier and critical nucleus size versus the loaded nanoparticle size (d(nuclear)(*)/d) was simulated by the model combining the surface roughness and superhydrophobility with the critical nucleation energy. The optimized loaded nanoparticles size maintained the proper roughness and d(nuclear)(*)/d to ensure the desired performance of antifouling. The improved superhydrophobic surface enhanced the anti-wetting ability of the membrane for vacuum membrane distillation (VMD) purpose. The resulting modified membrane possessed good anti wetting ability and stable anti-fouling performance during long-term continuous and batch operation of VMD treating high salinity water system. The fouling rate of the fabricated membrane was decreased to 20% of the one of the original membrane under 15 wt% high salinity feed condition.