A Rubberlike Stretchable Fibrous Membrane with Anti-Wettability and Gas Breathability

The fabrication of a stable, anti-wetting surface is a very challenging issue in surface chemistry. In general, superhydrophobicity highly depends on the surface structure. Moreover, mechanical deformation of the surface structure can produce dramatic changes in the surface wetting state, and in some cases, may even result in a complete loss of the surface's unique wettability. However, the study of stable surfaces under mechanical deformation conditions has been limited to flexible surfaces or small strain. Here, a mechanically stable superhydrophobic membrane is presented, which possesses high stretchability and gas breathability. The membrane, which consists of an elastic polyurethane fibrous matrix coated with polyaniline hairy nanostructures and polytetrafluoroethylene, exhibites excellent superhydrophobic properties under >= 300% strain. The breathability and wettability of the membrane is examined by examining various static and dynamic wetting parameters. The robust membrane maintaines its anti-wettability (water contact angle similar to 160 degrees, hysteresis similar to 10 degrees) for 1000 stretching cycles. It is also determined that the stretchable and superhydrophobic surface suppresses the fragmentation and rebound of impact droplets, compared with rigid superhydrophobic surfaces. Finally, underwater gas sensing is demonstrated as a novel application.