Thermal Performance of Silica-Coated Wood Particles

Wood is one of the most widely used sustainable lignocellulosic materials, with numerous applications in consumer goods and the construction sector. Despite its positive properties, such as a high strength-to-weight ratio, thermal insulation, and low density, wood’s natural thermal degradation can limit its potential applications. In composite applications like wood–plastic composites, the particle morphology and surface topography must be preserved to support intimate polymer–wood contact and mechanical interlocking. This study investigated the efficacy of a thin silica coating for thermal protection, which was applied via an in situ sol–gel method using the precursor tetraethoxysilane (TEOS). The wood particles and treatments were characterized using particle size analysis, physisorption, FTIR, SEM, XRD, and TGA analyses. After treatment, the specific and microporous surface area of wood particles increased by 118% and 97%, respectively, an effect of the porosity of silica itself. FTIR spectra of the silica-treated wood displayed peaks corresponding to Si stretching, and SEM micrographs confirmed a successful silica coating formation. TGA showed that the silica coating increased the temperatures needed to degrade the underlying hemicellulose and cellulose by 16 °C for all treatment levels. This particle-scale coating provided a promising method for producing thermally protected, functionalizable wood fillers for composites that maintain the filler geometry and potential mechanical interlocking, offering an attractive upcycling pathway for wood residues.