Dimensional stabilization of wood by using microporous silica-aerogel

The expected result of the research was the improvement of the dimensional stability through bulk hydrophobization, as a result of impregnation with microporous SiO2 aerogel. Two different wood species, beech (Fagus sylvatica) and scots pine (Pinus sylvestris) were investigated. Silica aerogel was prepared in situ in the wood tissue via a sol-gel process. The impregnation with silica aerogel was successful, as shrinking and swelling properties decreased by 25-40%, depending on wood species, beside a low weight percent gain (6.9-9.4%). Water uptake and equilibrium moisture content decreased significantly as a result of the treatments (30-60%). Beside some changes in the permeability, high hydrophobization effect was observed as one of the main reasons for the improved dimensional stabilization of the treatment. The treatment resulted in an obvious colour change as well. FT-IR measurements proved a chemical bonding of the silica aerogel to the cellulose structure of wood, that indicates a long-lasting effect of the treatment.