Weathering Performance of Wood Coated with a Combination of Alkoxysilanes and Rutile TiO2 Heirarchical Nanostructures

Abstract

The weathering performance of wood coated with a combination of rutile TiO2 hierarchical nanostructures and a sol-gel deposit of alkoxysilanes was determined by exposing three sets of specimens to UV light and water spray. The first set consisted of specimens coated with a mixture of methyltrimethoxysilane (MTMOS) and hexadecyltrimethoxysilane (HDTMOS). The second set consisted of specimens coated with nanostructural TiO2 followed by a mixture of MTMOS and HDTMOS. The third set consisted of uncoated control specimens. The wood coated with TiO2 followed by a mixture of MTDMOS and HDTMOS exhibited significantly less surface color change and weight loss as a result of UV lightinduced degradation and erosion from water spray in comparison with the other groups. However, the coated surfaces were gradually transformed from hydrophobic to hydrophilic. Despite this apparent weakness, the MTMOS/HDTMOS/TiO2 coating, with superior photostabilization properties and resistance to surface erosion, may be useful for improving the weathering performance of wood coated with semi-transparent wood stains.

Enhancing Weathering Resistance of Wood—A Review

“…Zheng et al [ 110 ] reported that the wood samples coated with nanostructural TiO 2 followed by a mixture of methyltrimethoxysilane and hexadecyltrimethoxysilane exhibited improved resistance to discolouration and weight loss during accelerated weathering. However, after 960 h of exposure to UV radiation and water spray, the specimens showed a drastic decrease in surface water contact angle which can be explained by the effect of the photoactivity of TiO 2 [ 111 ].…”

Hybrid sol-gel materials for realization of radiation protective coatings—a review with emphasis on UV protective materials

“…3 Scanning electron micrographs of textile fabrics made from cotton and polyester fibers. Shown are untreated fabrics and fabrics with silica sol coating and hybrid coatings from silica and an inorganic IR absorber from doped tin oxide A prominent example is the use of modified sol-gel coatings to protect wood from sun light and weathering [31][32][33]. For this application, silica sols can be modified with color pigments of various iron oxides.…”

Application of Nanotechnology in Wood-Based Products Industry: A Review

“…The mixture of benzotriazoles, HALS and both TiO 2 and ZnO nanoparticles was confirmed as one of the most effective treatments for colour stabilisation of wood due to UV and VIS spectrums. It was reported that wood specimens coated with rutile TiO 2 and a mixture of methyltrimethoxysilane and hexadecyltrimethoxysilane showed superior weathering performance and improved resistance to surface colour change and weight loss [ 176 ]. The TiO 2 coating also was found to apparently enhance the colour stability of wood during UV light irradiation without water spray.…”