Robust superhydrophobic PVDF membrane constructed by template-assisted strategy via thermally induced phase separation for rapid water-in-oil emulsions separation

The bottlenecks of low separation efficiency and unsatisfactory structural stability restrain the advancement of superhydrophobic membranes in water-in-oil emulsions separation. In this work, a facile template-assisted strategy was proposed to construct the robust membranes by casting the polyvinylidene fluoride (PVDF) solution onto the hot stainless plate with the silicon dioxide (SiO 2 ) suspension sprayed as the template in advance. The underlying merits of SiO 2 incorporated for the construction of hierarchical structure characteristics and meanwhile served as the reaction sites for the follow-up fluorinated modification were demonstrated, in terms of developing highly-permeable membrane with super hydrophobicity. Correspondingly, the best performing membrane of M−300F shows the fluxes of 2351 ± 225 L·m −2 ·h −1 and 2752 ± 210 L·m −2 ·h −1 in the separation of simulated water-in-toluene and water-in-hexane emulsions, and meanwhile exhibits the water rejection of 98.9 ± 0.6 % and 99.1 ± 0.3 % respectively. Results reported in this work might demonstrate a new insight in constructing superhydrophobic membranes for practical water-in-oil emulsions separation.