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本文研究了热处理(200—1100℃)对自制的一种硅胶的表面结构的影响;测定了BET比表面(低温氮气吸附法)、孔体积、乙醇的吸附-脱附等温线,计算了孔径分布,求得了最可几Kelvin半径。结果表明,杂质的存在明显地降低硅胶的热稳定性。在发生熔结以前,孔径分布基本不变,当发生熔结时,孔半径显著减小。红外光谱的测定表明,随着热处理温度的升高,硅胶表面缔合羟基(～3500cm~(-1))迅速减少,在～800°时已去除殆尽,而自由羟基(～3720cm~(-1))减少缓慢,在1100℃时才迅速消失。X-射线衍射图表明,发生熔结后的硅胶显示有β-鳞石英的衍射峰,说明出现了有序晶相。对上述实验结果,文中作了初步的解释。
The effects of heat treatment (200-1100 ℃) on the surface structure of a self-made silica gel were investigated. The BET specific surface area (low temperature nitrogen adsorption method), pore volume and ethanol adsorption-desorption isotherms were calculated. The pore size distribution , Get the most Kelvin radius. The results show that the presence of impurities significantly reduces the thermal stability of the silica gel. Before the sintering occurred, the pore size distribution remained essentially unchanged, and the pore radius decreased significantly when fusion occurred. The results of FTIR showed that the hydroxyl groups (~ 3500cm -1) on the surface of silica gel decreased rapidly with the increase of heat treatment temperature, and the hydroxyl groups (~ 3720cm ~ (- 1)) slowed down and disappeared rapidly at 1100 ° C. The X-ray diffraction pattern shows that the fused silica gel shows a diffraction peak of β -quartz indicating the presence of an ordered crystalline phase. The above experimental results, the article made a preliminary explanation.