Effects of exposure time on variations in the structure and hydrophobicity of polyvinylidene fluoride membranes prepared via vapor-induced phase separation

► Exposure time is favorable for a Porous skin and particle morphology in VIPS. ► Porous skin and particle morphology are beneficial to the hydrophobic surface. ► The micro-nano bionic spheres contribute to the high CA on the PVDF surfaces. ► Low surface energy also contributes to the high CA on the PVDF surfaces.