钠硼硅酸盐玻璃分相过程的NMR研究

Process of Phase Separation in Sodium Borosilicate Glass as Studied by NMR

利用29Si、11B、23NaMASNMR，研究了一定组成的Na2O－B2O3－SiO2玻璃在不同温度下其微结构随分相处理时间的变化．结果表明，随分相过程的进行，[SiO4]结构单元的非桥氧之间逐渐脱氧，聚集程度逐渐提高，富硅相中的[BO3]结构与氧结合转变为[BO4]结构并进入富钠硼相，两相成分差逐渐增大，分相是扩散传质的结果．在较高的分相温度下，玻璃结构调整较快，因而更早地接近分相的平衡态．

29Si, 11 B, 23Na MAS NMR were employed to study the structure change of the Na2O-B2O3SiO2 glass in the process of thermal treatment of phase separation. The results show that oxygenatoms are deleted among the [SiO4] structure units and the aggregation degree of Si increases inthe process of phase separation. In the meantime, the structure of boron atoms in silicon-richphase is transformed gradually from [BO3] to [BO4] and [BO4] units enter into sodium-boronrich phase. The difference between the Compositions of the two phases gradually increases. Thephase separation is the result of diffusion and mass transfer. Moreover, the glass has a morerapid structure adjustment rate at a higher temperature of thermal treatment, thus can get to theequilibrium state faster.