Intestinal villi-inspired micro-nano structured antifouling ceramic membranes with enhanced interfacial flow scouring for efficient oil-water separation.

Membrane fouling remains a major challenge limiting the long-term operation of membrane processes for oily wastewater treatment. Inspired by the fluid-regulating function of intestinal villi, a biomimetic ZnO/attapulgite (ATP) ceramic membrane with hierarchical villus-like micro-nanostructures was fabricated via in situ growth of ZnO nanoparticles on ATP. Strong interfacial bonding between ZnO and ATP ensured structural stability and endowed the membrane with superhydrophilic/underwater superoleophobic wettability. The membrane achieved a high permeance of 917.85 L·m-2·h-1·bar-1 and complete emulsion rejection during oil-water separation. After simple hydraulic cleaning, a flux recovery ratio of 82% was maintained, demonstrating excellent antifouling performance and operational stability. CFD simulations revealed that the hierarchical architecture enhanced hydraulic scouring through microvortex-induced interfacial shear, mitigating foulant deposition. MD simulations further showed that ZnO modification strengthened interfacial hydration, promoting the formation of a stable hydration layer and reducing oil adhesion. Together with the surface negative charge and antibacterial activity of ZnO, these effects synergistically enhanced membrane antifouling performance. This work elucidates the antifouling mechanism governed by interfacial fluid dynamics and provides a new strategy for designing high-performance membranes for complex oily wastewater treatment.