【摘要】 研究了氢气氛中熔制石英玻璃的脱羟机理 ,将这种连熔石英玻璃在空气中 70 0～ 90 0℃温度范围内热处理 ;用红外光谱仪测定羟基在2 .73 μm波长处的光谱透光率 ,并计算石英玻璃热处理前、后的羟基含量 .结果表明 :石英玻璃的脱羟是二级对峙反应 ,正方向是放热反应 ,活化能为 15 3kJ·mol- 1 ,逆反应活化能为 3 0 6kJ·mol- 1 ;反应由氢在石英玻璃中的扩散控制 ,在 70 0～ 90 0℃范围内升高温度将有利于降低石英玻璃的羟基含量 .同时测定了脱羟前后石英玻璃结构中氧缺位在 2 40nm处的紫外吸收峰的变化 .表明氧缺位与脱羟过程无本质联系 .更多还原

【Abstract】 The kinetic mechanism of dehydroxylation of quartz glass melted under hydrogen atmosphere was studied by heat_treatment in the temperature range of 700—900 ℃. The infrared spectra were tested and the concentrations of hydroxyl were calculated. The results show that the process of dehydroxylation belong to a second order opposite reaction, the positive direction is an exothermic reaction with an activation energy of 153 kJ·mol -1 , and the activation energy of negative direction is 306 kJ·mol -1 ; the process of dehydroxylation is controlled by the diffusion of hydrogen, the concentration of hydroxyl in the glass decreases with increasing the temperature in the range of 700—900 ℃. The UV absorption at 240 nm manifested the oxygen vacancy annihilation has no intrinsic dependence with the dehydroxylation.更多还原