Preparation of superhydrophobic coatings with alkyltrichlorosilanes for Pinus kesiya wood

Abstract To explore the typical alkyltrichlorosilane and optimal volume ratio of the alkyltrichlorosilane-toluene solutions for preparing superhydrophobic Pinus kesiya wood, four alkyltrichlorosilanes: methyltrichlorosilane (MTCS), butyltrichlorosilane (BTCS), dodecyltrichlorosilane (DTCS), and octadecyltrichlorosilane (OTCS) were each used to modify the wood samples at different volume ratios of alkyltrichlorosilane-toluene solutions. The Pinus kesiya wood specimens were immersed in the solutions to fabricate superhydrophobic coatings on the wood surface. The wettability of the modified wood surfaces was characterized by water contact angle and water uptake values. The chemical composition of the wood samples was analyzed using X-ray photoelectron spectroscopy (XPS) and attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR), and the surface morphology of the modified wood samples was observed using scanning electron microscopy (SEM). The result showed that all types of alkyltrichlorosilane-modified wood changed from hydrophilic to hydrophobic. The wood specimens had the highest water contact angle of 151.8 ± 0.4° and lowest water uptake of 18 ± 0.6 wt.% when 0.25 vol.% MTCS and 0.25 vol.% OTCS solutions were applied, respectively.