Antigravity Autonomous Superwettable Pumps for Spontaneous Separation of Oil–Water Emulsions

Abstract Oil–water separation based on superwettable materials offers a promising way for the treatment of oil–water mixtures and emulsions. Nevertheless, such separation techniques often require complex devices and external energy input. Therefore, it remains a great challenge to separate oil–water mixtures and emulsions through an energy‐efficient, economical, and sustainable way. Here, a novel approach demonstrating the successful separation of oil–water emulsions using antigravity‐driven autonomous superwettable pumps is presented. By transitioning from traditional gravity‐driven to antigravity‐driven separation, the study showcases the unprecedented success in purifying oil/water from emulsions by capillary/siphon‐driven superwettable autonomous pumps. These pumps, composed of self‐organized interconnected channels formed by the packing of superhydrophobic and superhydrophilic sand particles, exhibit outstanding separation flux, efficiency, and recyclability. The findings of this study not only open up a new avenue for oil–water emulsion separation but also hold promise for profound impacts in the field.