基于精细结构对二元钠硅酸盐玻璃核磁共振波谱的研究

利用精细结构表征系列(Q_i^{\mathit{jklm}})对二元钠硅酸盐玻璃的核磁共振波谱进行解析, 并结合量子化学模拟了多种精细结构. 研究结果表明, 精细结构的 ²⁹Si化学位移与桥氧键角呈线性相关; 实验所得Q_i^{\mathit{jklm}}结构的化学位移不随玻璃成分的改变而波动, 且Q_i^{\mathit{jklm}}结构的高斯峰更窄, 说明精细结构表征是二元钠硅酸盐玻璃基本特征结构的表达, 导致初级微结构的 ²⁹Si化学位移变化的本质是精细结构含量的变化. 核磁共振波谱表征的是近邻结构的空间信息, 采用Q_i^{\mathit{jklm}}结构表征能更精确地描述硅酸盐的微结构信息.

NMR Spectroscopic Study on Binary Sodium Silicate Glass Based on the Fine Structure†

A series of fine structure denotations(Q_i^{\mathit{jklm}}) was applied to analysis NMR spectra of binary sodium silicate glasse, and a variety of clusters was simulated by quantum chemistry ab initio. The results shows that the ²⁹Si chemical shift of the fine structure with the same Q_i is linearly related to the bridging oxygen bond angle. The chemical shifts of the experimental Q_i^{\mathit{jklm}} structure does not fluctuate with the glass’ composition, and the Gaussian peak of the Q_i^{\mathit{jklm}} structure is narrower. It is indicated that the fine structure characterization is a representation of the basic characteristic structure of the binary sodium silicate glass. It is found that there is a certain gap between theoretical values and experimental values. The results shows that there are multiple configurations of Q_i^{\mathit{jklm}} structures coexisting in the glass, and the interaction between neighboring structures was characterized by NMR. However, the Q_i^{\mathit{jklm}} structural characterization can describe the configuration of various silicate-oxygen tetrahedron more precisely.