Improved UV resistance of wood with nano-hybrid coatings

Wood and wood-based composites are widely used as construction, furnishing and decorating materials for ecological and aesthetic reasons. However, wood surfaces are easily damaged when exposed outdoors to UV radiation.Wood products with improved UV resistance properties can be achieved by using coating systems based on the sol-gel technique.By optimizing the composition of the sol-gel, the properties of the thin coatings can be directed to the desired direction.The objective of this study was to investigate the effect of sol-gel hybrid coatings on the UV-resistance of wood.The sol-gel coatings used were based on alkoxysilanes.Scots pine sapwood (Pinus sylvestris) samples were treated with two different sol-gel coatings and with a coating containing inorganic pigments.Treatments of pine wood with these thin coatings did not change the natural appearance of the substrate (gloss and color quite equal to that of untreated wood).The samples were exposed to UV light and the efficacy of the treatments was evaluated by means of surface characteristic measurements (e.g., gloss, contact angle, color measurements) before and after the exposure.The results obtained show that the hybrid nanocomposite sol-gel treatments restrain color changes of wood surfaces