木材、竹材及其炭化物负载SiO_2凝胶的比较

A Comparative in SiO_2 Gel Loading Performance of Wood, Bamboo and Their Carbonized Products

采用单一浓度溶胶浸渍和梯度浓度溶胶浸渍2种方法将SiO2溶胶注入竹材、木材、竹炭和木炭4种材料内部,探讨材料微观结构、炭化前后、溶胶浓度以及浸渍方法对材料凝胶负载率的影响。结果表明:竹材的SiO2凝胶负载率低于竹炭,二者的凝胶负载率显著小于木材和木炭;木材和木炭凝胶负载性能差异与所浸渍溶胶的浓度有关;相比于使用单一浓度浸渍,浓度梯度法浸渍可有效提高材料的负载率。

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.