Effect of increasing Fe2O3 content on the chemical durability and infrared spectra of (25 − x) Na2O−x Fe2O3–25PbO–50SiO2 glasses

The effect of replacing Fe2O3 for Na2O on the chemical durability of sodium lead silicate glasses of the compositions, (25 − x) Na2O-x Fe2O3–25PbO–50SiO2, where x = 0, 5, 10 and 15 (mol%) has been studied. FTIR, density and thermal expansion coefficient have also been measured. Replacing Fe2O3 for Na2O increases the chemical durability of the glasses. An increase in the packing of the structure is observed with increasing the Fe2O3 content as revealed by the increase in density, transition and softening temperatures and decrease of thermal expansion coefficient. These results are attributed to decreasing of the non-bridging oxygens in the glass structure as confirmed by FTIR spectra and by the decrease or vanishing of the infrared absorption peaks due to H–O–H group or water molecules vibrations.

► We examined replacement of Na2O by Fe2O3 in sodium borate glass. ► A packing of the glass structure is proposed. ► The compaction relies on changes in physical and spectroscopic properties. ► We report an improvement in the chemical durability of the glasses. ► The glasses are good candidate for waste immobilization.