Three-Dimensionally Printed Bioinspired Superhydrophobic Packings for Oil-in-Water Emulsion Separation

The separation of oil-water emulsions has attracted considerable attention in recent years. The main challenge is to find new cost-effective ways to develop a separation technology that has the potential for scaling up treatment. In this study, benefitting from the idea in traditional chemical engineering processes, we report on three-dimensionally printed superhydrophobic poly(lactic acid) (PLA) packings for oil-in-water emulsion separation. Superhydrophobicity was achieved through a bioinspired modification process including selective solvent etching and nanoparticle decoration. The obtained superhydrophobic PLA packing has an air-water contact angle of 150° and a water adhesion force of 22 μN. A maximum separation efficiency of 95% was achieved while retaining a relatively high flux of 7.5 kL m^-2 h^-1 by tailoring the internal geometry. Our approach demonstrates a promising method to fabricate packings with user-defined and functional features. The relatively low-cost and efficient fabrication process is beneficial in industrial applications.