Multifunctional Superwetting Sea-Urchin-Mimetic Nanosheet-Based Interface for Remote Oil-Water Separation

Abstract

Rapid and large-scale oil spill remediation remains an urgent environmental and technological challenge. Here, we present a transformative, multifunctional bio-inspired platform for on-site, remotely actuated, and contactless oil-water separation that integrates an advanced membrane with electronics deployment. Here, we present a sea-urchin-mimetic, fluorine/silane-free composite that enables remote, on-site oil-water separation through molecular-level modulation of surface energy and hierarchical roughness through micro/nano structures. The architecture integrates oleic acid-functionalized barium carbonate (FBC) with reduced graphene oxide (rGO) nanosheets, where FBC introduces polar-nonpolar asymmetry and spine-like protrusions, while rGO contributes ultra-low surface energy and electron-delocalized reinforcement. This dual design stabilizes a metastable Cassie-Baxter state by coupling air entrapment with pi-pi-driven energy minimization at the solid-liquid interface, resulting in extreme water repellency (WCA > 150 degrees) and instantaneous oil affinity (OCA approximate to 0 degrees). The coating exhibits exceptional corrosion inhibition (>90%) in simulated seawater, self-cleaning against complex biofluids and beverages, and high-capacity oil uptake (15-65 g/g) with >97% efficiency and recyclability after repeated use. Integrated into a dolphin-inspired, Wi-Fi-controlled mini-bot system, this material enables remotely controlled, contactless oil recovery, establishing a new paradigm in adaptive, non-messy, hazard-free oil-spill remediation in contaminated zones.