Unexpected Superhydrophobicity on a Wide Range of Substrates via a One-step Immersion in Aqueous Solution without Hydrophobic Agent

Superhydrophobic surfaces were unexpectedly constructed by immersing a variety of substrates (aluminum sheet, melamine sponge, cotton fabric, and wood) into an aqueous solution containing tea polyphenols and metal ions (Fe2+, Ag+, Ce3+) and the potential applications in corrosion resistance for superhydrophobic aluminum, water absorption resistance for superhydrophobic wood, oil/water separation for superhydrophobic sponge and self-cleaning for superhydrophobic fabric were investigated. Superhydrophobic surfaces were unexpectedly constructed by immersing substrates into an aqueous solution containing tea polyphenols (TP) and metal ions. Metal ions were chelated with TP to generate rough surface structures and reduced to metal particles, which were active to anchor the carbon contamination from the atmosphere. Superhydrophobicity was unexpectedly achieved by the joint effect of surface roughness and surface carbon contamination.