Robust superhydrophobic wood obtained by spraying silicone nanoparticles

Abstract

Silica nanoparticles, usually synthesized via Stöber reactions in the presence of a suitable amount of an ammonia catalyst, are frequently used in the fabrication of self-cleaning surfaces. However, to achieve superhydrophobicity, the nanosilica-modified surfaces need to be further functionalized with low-surface-energy materials. Here, we report the preparation of polymethylsiloxane nanoparticles in a facile way, i.e., the hydrolysis of trichloromethylsilane in toluene under ambient conditions in the absence of a catalyst. The resulting gel-like solution can be applied to substrate surfaces by the convenient method of spraying. Wood slides were used as substrates, and the spray-coated wood without any further surface elaboration became extremely superhydrophobic. Notably, it was observed that the superhydrophobicity of the coated wood is mechanically stable against repeated finger rubbing because of the macroscale and microscale roughness of the wood surfaces that serve as a barrier against mechanical damage.