Superhydrophobicity of polyvinylidene fluoride induced by integrating liquid-exfoliated hexagonal boron nitride nanosheets

The superhydrophobicity of polyvinylidene fluoride (PVDF) membranes can be achieved by adding a small amount of hexagonal boron nitride nanosheets (h-BNNSs) during the preparation process. The h-BNNSs can be fabricated by two steps of facile ultrasonication of commercial h-BN powders in water and subsequent centrifugation process. The introduction of a small amount of h-BNNSs into PVDF will result in structure and morphology changes of final PVDF membranes. The changes of the structure and morphology can significantly reduce the surface wettability of PVDF membranes, even generating superhydrophobicity. However, the superoleophilicity of PVDF membranes is well kept, which is not influenced by the introduction of h-BNNSs. The excellent superhydrophobicity and superoleophilicity make these porous h-BNNS/PVDF composites to be promising candidates for separating oil and water as membranes in practical oil-polluted waste water treatment.