Improved Hydrophobicity of Vapor Coated Chlorosilane Self Assembled Monolayers using Evaporative Drying of Solvent and Annealing

A novel method to modify the surface morphology of the vapor coated chlorosilane-based self assembled monolayer (SAM) on glass substrates was proposed. This so-called "interrupted-growth" process involves a combination of evaporative drying of solvent and annealing processes. Atomic force microscope measurements revealed the conglomerates of SAM molecular chains with possible multilayer rearrangements. Contact angle increment as high as 30deg was observed while hysteresis remains unaltered. The possible mechanism of conglomerates formation was proposed. The method has been successfully applied to further improve the superhydrophobicity of polydimethylsiloxane (PDMS) nanopillar-based surface.