Development and Topochemistry of Wood-Inorganic Composites

研究了一种利用烷氧基硅烷的溶胶-凝胶过程，利用结合水在木材细胞壁内形成硅胶，制备木材-无机复合材料的方法。发现这种硅胶选择性地在细胞壁内形成，并且发现对于具有较高结合水水分含量的样品，形成的凝胶的量较高。对不同硅胶含量的复合材料进行了评价，结果表明，硅胶含量越高，复合材料的尺寸稳定性和阻燃效果越好。将超声波辐射用于上述方法中，以促进烷氧基硅烷的水解，发现其处理有效地增加了硅胶在木材细胞壁中的吸收，作为对比，本文还制备了孔腔内填充硅胶的木材-无机复合材料，研究了无机材料的局部化学效应对木材尺寸稳定性和阻燃性能的增强作用。结果清楚地表明，与在细胞腔中形成的硅胶相比，在细胞壁内形成的硅胶不仅对于尺寸稳定性而且对于阻燃效果更有效。

A method was developed for preparing wood-inorganic composites with retaining a porous structure characteristic of wood, and it involves the sol-gel process of alcoxysilanes to form silica gel within wood cell walls by the use of bound water. This silica gel was found to be selectively formed within the cell walls and the amount of the gel formed was found to be higher for the specimens with the higher moisture content of bound water. Evaluation of the prepared composites with different amounts of silica gel formed indicated that the composites with the higher amount of the gel retained revealed the better dimensional stability and fire-retarding effect.The ultrasonic radiation was applied to the above method to promote the hydrolysis of the alkoxysilane and its treatment was found to be effective to increase the uptake of the silica gel within the wood cell walls, which has resulted in the improvement of the dimensional stability as well as fire-retarding effect.Just for comparison, wood-inorganic composites filled with silica gel within the cell lumens were also prepared, and topochemical effects of the inorganic materials was studied on property enhancement in dimensional stability and fire-retarding effect. The result clearly indicated that silica gel formed within the cell walls was more effective not only for dimensional stability but also for fire-retarding effect, compared with silica gel formed within the cell lumens.