Na2O-B2O3-SiO2系统溶胶-凝胶-玻璃转变过程反应机理

Reaction Mechanism on the Conversion of Na_2O-B_2O_3-SiO_2 Sol-Gel into Glasses

采用高温热饱和方法制备干胶时,水解和聚合反应继续进行,聚合反应使链状分子向枝状分子转变,Na2O-B2O3-SiO2系统干胶在100℃干燥后,Q2,Q3,Q43种类型的基团同时存在。当在600℃烧成的Na2O-B2O3-SiO2系统干胶时Q4基团占主要了,这时硅胶网络由较低聚合度变成较高聚合度的硅氧网络了。但在600℃烧成的Na2O-B2O3-SiO2系统玻璃对称性差,该峰对称性差的原因可以这样理解,即基团中Si原子有1个或2个被硼原子取代而导致的结果,即形成了Si-O-B键,在600℃得到加强,这一现象已经被红外吸收光谱的结果得到证实。

The hydrolysis and polymerization reaction process from the sol to gel and to glass during the period of Na2O-B2O3-SiO2 was still carried out. The chain molecule can be changed into branch molecule. The Q2, Q3, Q4 groups can exist at the same time after drying at 100 ℃. The Q4 groups can exist mostly after drying at 600℃. The polymerization degree of silicon-oxygen become high, but the symmetry is not good because SiOB bond was formed, and the results correspond to IR results .