Glass Formation and Chemical Durability of Chromium Oxide-Containing Phosphate Glasses

Abstract

Phosphate glasses containing a large amount of chromium oxide were prepared and their chemical durability was examined. Among various phosphate glasses, metaphosphate glass was chosen as the base glass composition because of its chemical stability. The maximum amount of chromium oxide included in the glass was found to be 23mol%.
The chemical durability of these chromium oxide-containing phosphate glasses was excellent. Particularly, the alkali resistance of phosphate glass was imporved by the addition of chromium ions. Both the weight loss and dissolution of chromium ions for the best glass were almost zero in 1N sodium hydroxide aqueous solution after immersing it for 12 hours at 70°C. The fact that these metaphosphate glasses excelled other phosphate glasses in water, acid or alkali resistance was explained based on the difference in glass structure.