Superwettability‐based separation: From oil/water separation to polymer/water separation and bubble/water separation

Abstract

Abstract The separation of oil/water mixtures, polymer/water mixtures, or bubble/water mixtures has broad applications. In this paper, we aim at extending the well‐developed wettability‐based oil/water separation strategy to separate the mixtures of liquid polymers and water and separate bubbles from water. The micro/nanostructures are simply produced on a stainless steel mesh by femtosecond laser treatment to endow the mesh with superhydrophilicity in the air and superoleophobicity, superpolymphobicity, and superaerophobicity in water. The underwater superoleophobicity, superpolymphobicity, and superaerophobicity enable the structured mesh to have the ability of oil/water separation, polymer/water separation, and bubble/water separation. Water can pass through the mesh due to the superhydrophilicity of the laser‐structured mesh. Whereas, the oils, the liquid polymers, and the bubbles in water are intercepted by the structured mesh because such a water‐wetted mesh has strong repellence to oils (underwater superoleophobicity), liquid polymers (underwater superpolymphobicity), and bubbles (underwater superaerophobicity). As a result, the oil, the liquid polymer, and the bubble are successfully separated from water by using the as‐prepared superwetting mesh. We believe that the diversified wettability‐based separation processes will have wide potential applications in environmental protection, energy utilization, industrial manufacture, agricultural production, and so on.

Keywords

• bubble/water separation
• oil/water separation
• polymer/water separation
• underwater superaerophobicity
• underwater superpolymphobicity