3D-Printed Superhydrophobic Copper Mesh for Oil/Water Separation and Microplastics Capture

Abstract

This study develops a robust superhydrophobic and superoleophilic copper mesh via a facile two-step process involving chemical etching and lauric acid modification. The resulting surface possesses a hierarchical micro/nanoscale roughness and an ultra-low-energy coating, yielding a water contact angle of 160° and exceptional oil affinity. This engineered wettability enables the mesh to achieve separation efficiencies exceeding 95% for various oil-water mixtures. Furthermore, the material demonstrates an excellent capability for removing polypropylene (PP) and high-density polyethylene (HDPE) microplastics, with efficiencies above 94% at moderate concentrations, via synergistic hydrophobic interactions. Remarkably, the integration of a trace oil phase (e.g., hexane) was found to further enhance microplastic capture by acting as a hydrophobic bridge. The mesh also exhibits outstanding chemical stability across a wide pH range (1–14) and maintains consistent performance over multiple operational cycles. With its multifunctional performance, straightforward fabrication, and proven stability, this copper mesh presents a highly promising and practical material for advanced applications in oily wastewater treatment and complex water remediation.