Nanotexturation-induced extreme wettability of an elemental tellurium coating

Abstract

A combination of microscale and nanoscale texturation has been achieved in hierarchically structured Te coatings deposited onto a variety of substrata via self-catalyzed vapor transport. The coating thickness and roughness of the deposited Te surfaces are tunable via control over the reaction temperature and diffusion flux. The intricately structured surfaces exhibit sub-40 ms flash spreading of water to eventual macroscopic contact angles of 0° without any need for surface cleaning. The wettability characteristics of the surface are ascribed to the role of the hierarchical roughness in stabilizing the droplet/surface interactions in the Wenzel regime. The surfaces retain their hydrophilic properties over several months and are especially notable as a conductive addition to materials exhibiting unusual superwetting behaviour.