SiO2-Na2O-B2O3 density: A comparison of experiments, simulations, and theory

This paper is devoted to a comparison of experimental, simulation, and theoretical results on the density of SiO2-B2O3-Na2O glasses. It is found that theoretical and simulation densities do compare favorably with experimental values yet simulations give a better estimate of the density of the samples. Furthermore, the structural make-up (i.e. types of borate and silicate units) of the ternary glasses and the volume of the elementary units have also been investigated with simulations and compared to theory. These results are found to compare favorably when R < R-d1 (R = [Na2O]/[B2O3], K = [SiO2]/[B2O3] and R-d1 = 0.5 + 0.25K) yet variations do exists when R > R-d1. These variations include more Na+ ions attaching to the borate network in simulations than theorized. (C) 2013 Elsevier B.V. All rights reserved.