The study of physico-mechanical properties of SiO2-impregnated wood under dry and saturated conditions

Abstract

This research has demonstrated that SiO 2 impregnation under high vacuum pressure of -90 kPa can signi cantly reduce porosity by almost 10%, and improve mechanical and viscoelastic properties of spruce wood under dry and saturated states. Characterization methods, such as Impact test, DMA, SEM, EDS, Porosity and SAXS tests were conducted on nontreated and -90 kPa treated spruce wood samples under dry, saturated and submerged states to analyze the synergistic effect of high vacuum SiO 2 impregnation pressure on wood's properties. The results showed that high vacuum impregnation pressure had a signi cant positive reinforcing effect on wood's properties. It increased the impact resistance of wood under dry and saturated conditions. Additionally, the high vacuum impregnation technique was able to overcome the water-induced softening effect and caused a signi cant increase in the Storage modulus through uniform dispersion of the SiO 2 particles in the wood's vascular structure. Consequently, the impregnation reinforced the wood, and ameliorated its capacity to absorb energy. High vacuum impregnation was also able to counteract the plasticizing effect of the water molecules and signi cantly increased the Loss modulus by increasing the internal friction and cohesion of the wood components with the addition of the nanoparticles to the vascular system, which increased the wood's capacity to transform and dissipate energy. Quantitatively and qualitatively, impregnation under a vacuum pressure of -90 kPa exhibited an effective obstruction of the vascular structure of spruce wood. In all conditions, high vacuum impregnated samples showed signi cant enhancements over non-treated samples. This research demonstrated that high vacuum SiO 2 impregnation is an effective wood processing techniques. Multiple materials and applications could bene t from this research wherein high strain-rate deformations is expected to occur or when simultaneous elastic behaviour of wood and its damping energy is needed. This study could also pave the way for research on the synergistic effect of SiO 2 impregnation and water absorption on the viscoelastic behaviour of wood.