Study of the structural evolution in phosphate glasses using Molecular Dynamics simulations

Abstract

This thesis presents the study of the structural changes in ternary zinc magnesium glasses. Compositional effects on the structural properties of the ternary zinc magnesium phosphate glasses were studied for the development of the glasses with the improved chemical durability. The basic methodology for the study is molecular dynamics simulations. The short range structures in glasses were examined using the pair distribution function, angular distribution function and coordination number analysis. Also the glass transition temperature was measured for different compositions. The short range structure of the simulated glasses was observed and the results were validated with the results obtained from simulations and the experimentally measured data. It was found that the backbone structure of the phosphate is not affected by the change in composition. As the zinc oxide was replaced by the magnesium oxide the chemical durability of the glass was increased. The results for the glass transition temperature show an increase in transition temperature with the replacement of MgO by ZnO. It indicates the formation of more chemically impervious bonds with increase in magnesium oxide content. The glass with the enhanced chemical durability will be more impervious to the aqueous attack.