基于精细结构对二元钠硅酸盐玻璃核磁共振波谱的研究

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

利用精细结构表征系列(Q_i^(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^(jklm)结构的化学位移不随玻璃成分的改变而波动,且Q_i^(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^(jklm)结构表征能更精确地描述硅酸盐的微结构信息.

A series of fine structure denotations(Qi^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 29 Si chemical shift of the fine structure with the same Qi is linearly related to the bridging oxygen bond angle.The chemical shifts of the experimental Q^jklm i structure does not fluctuate with the glass’composition,and the Gaussian peak of the Q^jklm i 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^jklm i structures coexisting in the glass,and the interaction between neighboring structures was characterized by NMR.However,the Qi^jklm structural characterization can describe the configuration of various silicate-oxygen tetrahedron more precisely.