Antiweathering properties of a thermally treated wood surface by two-step treatment with titanium dioxide nanoparticle growth and polydimethylsiloxane coating

The weathering of thermally treated wood by light radiation and water is an important problem for the wood used in outdoor applications. In this study, a durable hydrophobic and UV-resistant layer was successfully formed on the surface of thermally treated wood at room temperature after in situ deposition of titanium dioxide (TiO2) nanoparticles and a polydimethysiloxane (PDMS) coating. The morphology of the rutile TiO2 nanoparticles formed on wood surface, varying from spherical (A-TiO2) to acicular (B-TiO2), was tunable by the reaction time between the precursors. Even though the deposited TiO2 was proved to make the wood surface UV resistant, it was nondurable due to the poor leaching resistance. The successive coating by PDMS significantly improved the leaching resistance of TiO2 nanoparticles due to the superior hydrophobicity of PDMS. Therefore, the degradation of wood components was reduced, and the removal of chromophoric products in the thermally treated wood was also hindered.