The study of physico-mechanical properties of SiO 2 impregnated wood under dry and saturated conditions

Abstract This research has demonstrated that SiO2 impregnation under high vacuum pressure of -90 kPa can significantly 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 non-treated and -90 kPa treated spruce wood samples under dry, saturated and submerged states to analyze the synergistic effect of high vacuum SiO2 impregnation pressure on wood’s properties. The results showed that high vacuum impregnation pressure had a significant 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 significant increase in the Storage modulus through uniform dispersion of the SiO2 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 significantly 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 significant enhancements over non-treated samples. This research demonstrated that high vacuum SiO2 impregnation is an effective wood processing techniques. Multiple materials and applications could benefit 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 SiO2 impregnation and water absorption on the viscoelastic behaviour of wood.