Na environment, conductivity, and water leaching of sodium alkaline earth silicate glass

(Na2O)35.7(MO)7.2(SiO2)57.1 and (Na2O)33.7(MO)13.3(SiO2)53.4 glass materials that feature alkaline earth metals (M = Mg, Ca, Sr, Ba) were evaluated as Na+ conducting materials. Following glass synthesis from the melt under air at 1350 °C, Na environments, conductivity, and water leaching were investigated. 23Na NMR spectrometry indicated Na–O distances decreased in the order M = Mg > Ca > Sr > Ba. The conductivities and activation energies of conduction respectively decreased and increased slightly in the order M = Mg, Ca, Sr, and Ba. Regardless of M, the conductivities and activation energies of conduction of (Na2O)33.7(MO)13.3(SiO2)53.4 were lower and higher, respectively, than those of (Na2O)35.7(MO)7.2(SiO2)57.1. Na leaching into water decreased in the order Ca < Mg < Sr < Ba. For each M, (Na2O)33.7(MO)13.3(SiO2)53.4 was more resistant to leaching than (Na2O)35.7(MO)7.2(SiO2)57.1.