论文部分内容阅读
用程序升温热重法分析了SiO2及SiO2-PEG干凝胶的热物理化学行为，结果表明：采用不同的环境气氛对SiO2-PEG干凝胶进行热处理，聚乙二醇（PEG）表现出不同的热稳定性，并由此影响干凝胶的织构性质；通过对氮气气氛中得到的DTG曲线进行处理，得到不同温度段的表现活化能，说明SiO2干凝胶脱羟反应表现出动力学控制，而SiO2-PEG干凝胶随着温度的升高则表现出动力学控制逐步向表面羟基的扩散控制转变．
The thermophysical and chemical behaviors of SiO2 and SiO2-PEG xerogels were analyzed by temperature-programmed thermogravimetric analysis. The results showed that the PEG-PEG showed different morphologies when the SiO2-PEG xerogels were heat-treated with different ambient atmospheres Thermal stability of the xerogel, and thus affect the texture properties of the xerogel; by processing the DTG curve obtained in a nitrogen atmosphere to obtain the activation energy at different temperature ranges, indicating that the kinetics of the dehydration reaction of xylene xerogel shows kinetics , While the SiO2-PEG xerogel shows the kinetic control to gradually shift to the surface hydroxyl diffusion control with the increase of temperature.