Abstract: The physical and mechanical properties of bamboo or wood could be significantly changed by the impregnation of SiO₂ gel. The weight percentage gain (WPG) is the key indicator reflecting the quantity of SiO₂ gel impregnated into the materials, which directly determines the performances of the resultant products. In this paper, bamboo, bamboo charcoal, wood and charcoal were immersed in SiO₂ sol with constant or gradient concentrations respectively. The effect of microstructure, carbonization or not, sol concentration and impregnation methods on WPG was systematically investigated. The results show that the gel loading performance of bamboo charcoal was better than bamboo, but both were far worse than that of wood and charcoal. For wood and wood charcoal, the gel loading performance was relevant to the concentration of the sol. Compared to the impregnation route of constant concentration, the gradient concentration could effectively increase the WPG of SiO₂ gel in the four materials.

Key words: bambo, bamboo charcoal, wood, wood charcoal, SiO₂ sol, loading performance