A facile surface modification of a PVDF membrane via CaCO3 mineralization for efficient oil/water emulsion separation

Abstract

In order to solve urgent environmental problems caused by oil spills, it is meaningful and necessary to develop novel materials or techniques for efficient oil/water separation. Here, a new polyvinylidene fluoride (PVDF)-based composite membrane was successfully fabricated via a layer-by-layer self-assembly process, where the active sites were provided by pDA for the CaCO₃ growth. Importantly, the CaCO₃ structure could be regulated by the concentration of the precursor solution, showing the high flexibility of preparation. The as-prepared PVDF@pDA@CaCO₃ membrane possessed superhydrophilic/underwater superoleophobic property and superior anti-fouling ability. In addition, the optimal PVDF@pDA@CaCO₃-2 membrane showed a high permeation flux only under gravity, and the separation efficiency was as high as 99%. With the merits of low-cost and great separation performance, the as-prepared PVDF@pDA@CaCO₃ membrane exhibited great potential in practical industrial applications for highly efficient oil/water emulsion separation.