Dual Biomimetic Synergistic Effects of Cactus Spines and Desert Beetle Shells for Water-In-Oil Emulsion Separation.

Drawing inspiration from the unique properties of cactus spines and desert beetle shells, we have designed a biomimetic stainless steel mesh specifically for efficient water-in-oil emulsion separation. The tapered arrays of cactus spines are prepared by a light-curing-templating method, and the hydrophobic regions are constructed by adhering hydrophobic silica nanoparticles to the surface of the mesh. This innovative design takes full advantage of the unique properties of these two natural plants, which can agglomerate tiny emulsified water to achieve an emulsion-breaking effect only under static conditions. At the same time, the stainless steel mesh with the conical arrays has a high water-in-oil emulsion separation efficiency (up to 99.6%), high permeance (2400 L·m -2 ·h -1 ·bar -1 ), and good cycling performance. The concept of dual biomimetic explored in this work may extend beyond oil-water separation to encompass various applications, such as fog collection, droplet manipulation, and more.