“Nano-fishnet” shaped PCL/PU-based composite membrane as superhydrophobic oil-water separator

Abstract

Nowadays, there is a growing interest in the development of eco-friendly oil-water separation membranes with selective wettability. However, the poor mechanical property often limits their applications. Herein an environmentally friendly polycaprolactone/polyurethane-based composite membrane (PCL/PU4@PDA@SA) was prepared by coaxial electrospinning. The PCL/PU4@PDA@SA was ingeniously designed with PCL distributed in fibers and PU produced in the nodule of “nano-fishnet”. The PCL fibers bonded by PU had good mechanical properties and excellent stability. The “nano-fishnet” combining SA with low surface energy endowed the superhydrophobicity of PCL/PU4@PDA@SA surface. Due to its multi-stage pore structure, the PCL/PU4@PDA@SA demonstrated superior efficiency in oil-water separation. Even after 10 cycles, the separation efficiency was still higher than 99.54%. Additionally, the PCL/PU4@PDA@SA membrane had good self-cleaning performance, friction durability, and chemical stability. This research highlighted a way to design a sustainable separator with controllable composition distribution and morphology.