Advanced wood products with nanoengineered surfaces

Wood and wood products are widely used as construction, furnishing and decorative materials for ecological reasons and also by reason of the appealing appearance of wooden surfaces. However, wood and wood products also have some disadvantages. For example, dimensional changes in response to altering atmospheric conditions, susceptibility to biological attack and changes in appearance due to weathering restrict the end-use of wood. Recently, it has been observed that one of the most promising methods to improve and provide new properties for wood materials is to modify wood surfaces with multifunctional alkoxysilanes by sol-gel technology. The advantage of the sol-gel process is that it allows deposition of inorganic-organic polymeric networks on various substrates as a result of controlled hydrolysis and polycondensation of alkoxysilanes. The properties of sol-gel coatings, such as abrasion resistance, barrier properties, moisture behavior as well as adhesion to different substrates, are controlled by the surface properties of the coatings and the sol-gel process variables. In this work, the moisture behavior of pine (Pinus sylvestris) sapwood and heat-treated spruce (Picea abies) was studied. The results indicated that water uptake especially of pine wood was diminished by the hydrophobic sol-gel-coating.