Electrically Induced Underwater Superaerophilicity/Superaerophobicity Switching on Polypyrrole-Coated Mesh Films for Selective Bubble Permeation

Graphical A mesh film was prepared by coating polypyrrole (PPy) film on Ti mesh , which is underwater superaerophilic when PPy is doped with perfluorooctanesulfonate ions (PFOS − ), and becomes underwater superaerophobic as the PFOS − are removed. The transition of the wettability can be triggered by the electro-stimuli, and adjustable bubble permeation in water is also demonstrated based on the film. Recently, materials with controllable superwettability have attracted much attention. However, almost all studies focused on controlling wetting of water and oil; research on underwater gas bubble wetting control is still rare. Herein, we report a mesh film prepared by coating polypyrrole (PPy) film on Ti mesh. Briefly, the film mesh is underwater superaerophilic when PPy is doped with perfluorooctanesulfonate ions (PFOS − ), and becomes underwater superaerophobic as the PFOS − are removed. The transition of the wettability can be triggered by electrical stimuli, which is attributed to the cooperative effect between the rough structure and chemical components variation. The controllable wettability allows adjustable bubble permeation. It can be envisioned that the film will provide potential applications in the future, such as underwater bubble capture/release and microfluidic devices.