Shanghai Institute of Optics and Mechanics has made progress in studying the structure and properties of aluminum phosphate glass

Recently, Hu Lili, a research team of the High Power Laser Unit Technology Laboratory of the Chinese Academy of Sciences Shanghai Institute of Optics and Fine Mechanics, used a method combining experiment, molecular dynamics simulation and quantitative structure property relationship analysis (QSPR) to study aluminum phosphate glass, and the related research results were published in the Journal of the American Ceramic Society.

At present, aluminum phosphate glass is widely used in many fields, including biomedical materials, optical components, sealing materials, and nuclear waste solidification. There have been many studies on the short range structure of aluminum phosphate glass through experimental techniques, but the relationship between its properties and the medium range structure is still unclear. Molecular dynamics simulation has become an effective tool for research, playing an increasingly important role in revealing the structural origins of glass properties.

In this study, researchers combined experimental and molecular dynamics simulation methods to study the effect of Al2O3 on the short and medium range structures of aluminum phosphate glass, and established its structural property model using QSPR method. The accuracy of the simulation was verified through experimental results such as Raman and synchrotron radiation.

The simulation results indicate that the P-O-P bonds present in the glass network are gradually replaced by P-O-Al bonds as the Al2O3 content changes, playing an important role in the performance changes of the glass. Meanwhile, the long chains in aluminum phosphate glass are prone to form circular structures and are concentrated in the 4 to 20 membered rings. In addition, the QSPR model was established using three different structural descriptors and successfully correlated experimental data with simulation results, demonstrating good model predictability. This method provides new ideas for predicting glass properties and designing glass components.

Figure 1 establishes a quantitative structure performance relationship model using the (a) coordination number (CN), (b) Qn, and (c) ring size of aluminum phosphate glass as structural inputs. The columns from left to right show the relationship between the structural descriptor Fnet and experimental density, hardness, glass transition temperature, and thermal expansion coefficient, respectively.

Source: Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences