Use of hard sphere ionic model for glass: A method of analysing void space for comparing glass systems

摘要

The assumption that glass is composed of spherical ions of fixed radius (hence, volume) allows calculation of its void space. By referring to the molecular formula of the glass, the void space volume can be normalised with respect to unit oxide(-II) of the glass yielding, what is defined here as, the "normalised molecular void", Vv. Using available density data, calculations were made for binary silicate glasses in order to establish the quantitative relationship between Vv and the metal oxide content of the glass (metal oxides were Li_2O, Na_2O, K_2O, Cs_2O, BeO, CaO, SrO and Al_2O_3). These relationships were then used to investigate the extent to which the void space in ternary glasses (and hence molar volumes) could be predicted when sets of parent binary glasses were combined, not only in equal proportions but also in ratios ranging from 5:1 to 1:5.