Dimensional stabilization of wood by microporous silica aerogel using in-situ polymerization

Abstract

AbstractIn this paper, a method for dimensional stabilization of wood through bulk hydrophobization was investigated using a sol–gel process resulting in in-situ formation of microporous SiO2 aerogel. Two different wood species, beech (Fagus sylvatica) and Scots pine (Pinus sylvestris) were investigated. The incorporation of microporous silica aerogel inside the cell wall and lumen was verified by scanning electron microscopy, energy dispersive spectrometry and Fourier-transform infrared spectroscopy. A leaching test using paper as model material proved the bonding of the aerogel to the cellulose component of the cell wall, which indicates a long-lasting effect of the treatment. The modification of wood with silica aerogel significantly improved its hygroscopicity and dimensional stability, decreased the equilibrium moisture content and water uptake beside a low weight percent gain. Permeability was reduced as a result of the silica aerogel deposition in the macro- and micropores of the modified wood. The treatment resulted in an obvious colour change as well.