Laser Patterning for Improved Hydrophobicity of PVDF Microfiltration Membranes

The widespread use of chemical additives in conventional oil-water separation processes poses significant risks to aquatic ecosystems and contributes to secondary pollution, underscoring the urgent need for sustainable and efficient separation technologies. Polyvinylidene fluoride (PVDF) is a promising membrane material owing to its robust chemical stability and mechanical durability; however, its intrinsic hydrophilicity limits separation performance. Here, we present a laser etching strategy that constructs micro-scale surface roughness on hydrophobic porous PVDF membranes without the use of any chemical additives. This method can successfully endow PVDF films with superhydrophobic performance, with the water contact angle increasing from 86.88° to 156.24°. The treated membranes achieve a permeation flux of 864.89 L h-1 m-2 alongside an oil-water separation efficiency of 98.44%. Moreover, the laser patterning technique allows for customizable surface architectures, enabling selective filtration of target particles. This work establishes a scalable, additive-free route to high-performance PVDF membranes, offering a promising platform for environmentally compatible wastewater treatment and resource recovery.