2003 Vol. 3, No. 12 1701–1705 | Kenneth K. S. Lau, José Bico, Kenneth B. K. Teo, Manish Chhowalla, Gehan A. J. Amarantunga, William I. Milne, Gareth H. McKinley, and Karen K. Gleason
The study demonstrates the creation of a stable, superhydrophobic surface using vertically aligned carbon nanotube forests coated with a thin, conformal poly(tetrafluoroethylene) (PTFE) layer. This approach combines the nanoscale roughness of the nanotubes with the low surface energy of PTFE to achieve superhydrophobicity down to the microscopic level, where even micrometer-sized water droplets can be suspended on the surface. The superhydrophobic effect is confirmed through vapor condensation experiments in an environmental scanning electron microscope (ESEM). The PTFE coating is applied using hot filament chemical vapor deposition (HFCVD), which ensures a uniform and thin layer that preserves the nanotube forest structure. The resulting surface exhibits high contact angles (up to 170° advancing and 160° receding) and stable superhydrophobic behavior, even after repeated cycles of condensation and evaporation. The study also explores the dynamic behavior of water droplets on the coated nanotube forest, showing that the droplets bounce off the surface without wetting it. The findings highlight the potential of this method for applications such as microfluidic devices, antisolvents, antifouling surfaces, and nonbinding biopassive surfaces.The study demonstrates the creation of a stable, superhydrophobic surface using vertically aligned carbon nanotube forests coated with a thin, conformal poly(tetrafluoroethylene) (PTFE) layer. This approach combines the nanoscale roughness of the nanotubes with the low surface energy of PTFE to achieve superhydrophobicity down to the microscopic level, where even micrometer-sized water droplets can be suspended on the surface. The superhydrophobic effect is confirmed through vapor condensation experiments in an environmental scanning electron microscope (ESEM). The PTFE coating is applied using hot filament chemical vapor deposition (HFCVD), which ensures a uniform and thin layer that preserves the nanotube forest structure. The resulting surface exhibits high contact angles (up to 170° advancing and 160° receding) and stable superhydrophobic behavior, even after repeated cycles of condensation and evaporation. The study also explores the dynamic behavior of water droplets on the coated nanotube forest, showing that the droplets bounce off the surface without wetting it. The findings highlight the potential of this method for applications such as microfluidic devices, antisolvents, antifouling surfaces, and nonbinding biopassive surfaces.