Excellent performance of novel superhydrophobic composite hollow membrane in the vacuum membrane distillation

Abstract

To improve general polypropylene better performances of vacuum membrane distillation (VMD), we proposed a feasible strategy to obtain the high-performance superhydrophobic composite hollow membrane in this work. Herein, we prepared superhydrophobic porous hollow composite membrane via the filter coating method and phase inversion. We mainly used polydimethylsilane and polyvinylidene fluoride to construct thin composite layer on the substrate through the suction coating. And then, substrate was dipped into bath with silicas to produce superhydrophobic membrane with water contact angle (WCA) over 160°. The property of silica, distribution of elements, wetting, morphology, thermal stability and chemical stability of membranes were characterized by TEM, XPS, FTIR, WCA, SEM, AFM, DSC, wetting resistance and corrosion test, respectively. In the 120 h VMD with different complex feeds, the flux of the modified membrane finally was over 12. 2 kg/(m2 h), and the rejection rate was over 99.99% with good organic pollutants resistance. Modified superhydrophobic membrane improved the low wetting resistance, flux, rejection and antifouling of polypropylene membrane in 120 h VMD to treat organic pollutant brines. These results illustrated that the treated membrane was available in practice desalination of imitate seawater.