Study on the structure change and devitrification of high silica glass particles with B₂O₃ modification by Raman, IR and MAS NMR spectroscopies

The devitrification behavior of glass depends on its network structure. High silica glass particles were prepared using a sol-gel method. The network structure modification was achieved by heat treatment at 1050 °C for 1 h after coating with 3 wt%∼ 5 wt% B₂O₃. The relationship between structure change and devitrification behavior of high silica glass particles with B₂O₃ modification was investigated by Raman, IR, ¹¹B MAS NMR,²⁹Si MAS NMR, and X-ray powder diffraction. The results demonstrated that the network structure units of high silica glass were comprised of BO (bridging oxygen), NBO (non-bridging oxygen, Q₂ and Q₃), [BO₄], and [BO₃]. It was found that Q₂, Q₃ and [BO₃] could be converted into Q₄ and [BO₄] under the effect of B₂O₃modification. As the network structure of high silica glass was repaired by B₂O₃ modification, the devitrification behavior of high silica glass was prevented.