Electrospun Differential Wetting Membranes for Efficient Oil-Water Separation

Separation of low viscous oil from water has attracted immense attention in recent times due to the ever-increasing amount of oily industrial wastewater discharge and frequent oil spill accidents. Hence, there is a persistent demand for the fabrication of robust oil-water separation membranes. Herein, robust oil-water separation membranes are successfully fabricated by direct electrospinning of poly(vinylidene fluoride-co-hexafluoropropylene) and fluorinated polyhedral oligomeric silsesquioxane composite mixture. These hybrid membranes exhibit differential wetting (highly hydrophobic/superoleophilic) behavior for water and oil. The contact angle made by water and low viscous oil (hexane) with the membrane are measured to be 145 and 0 degrees respectively. The nanofiber membranes efficiently separate low viscous oil from water in a single-step with separation efficiency of nearly 100%. Furthermore, the results demonstrate that the membranes are robust and durable exhibiting differential wettability even after several oil-water separation cycles. The results reveal the potential of their use for real-time industrial wastewater treatment applications.