Surface tension and density of molten glasses in the system La2O3Na2Si2O5

Abstract

Surface tension, density, and volatility of sodium disilicate, modified by additions of 1%, 5%, 10%, mole La₂O₃, have been evaluated at temperatures varying from 900 to 1500°C, under highly reducing conditions. These results and related data (such as activation energy of evaporation reaction; thermal expansivity; temperature coefficient of surface tension; nonideal behaviour; surface adsorption) have made possible interpretation of the role played by lanthanum in modifying the properties of the base glass.