Formation of highly hydrophobic wood surfaces using silica nanoparticles modified with long-chain alkylsilane

The so-called lotus effect has inspired the production of highly hydrophobic wood surfaces based on a two-step process consisting of growing nanofilms on the wood substrate (Chinese fir) with silica sol followed by hydrophobization with hydrolyzed hexadecyltrimethoxy-silane (HDTMS). The microstructure and chemical composition of the nanofilm coating were examined by field emission scanning electron microscopy, energy dispersive X-ray and Fourier transform infrared spectroscopy. The hydrophobicity of the treated wood was evaluated by water contact angle measurements. The results show that spherical nanoparticles were deposited uniformly on the wood surface, and the long-chain hydrophobic HDMTS was covalently linked to the surface of silica particles. The elevated hydrophobicity of wood was manifested by the water CA of about 141 degrees on the longitudinal surface and 150 degrees on the transverse surface.