CONDUCTANCE STUDIES ON SODIUM SILICATES.

Abstract

Sodium silicate solutions with silicon dioxide: sodium monoxide mole ratios of 3. 41 : 1 and 3. 98 : 1 were dried to form gels. Some conductance studies were carried out on the sodium silicate as it dried, and when the dried material was heated up to 160C. The results suggest that conduction is mainly due to sodium ions both in the solution and in the gel; to this extent the mechanism of conduction is similar to that in sodium silicate glasses. The gel has a much higher conductance than a glass of similar Na//2O : SiO//2 ratio, and this is probably because the gel contains hydroxyl ions and hydrated silicate ions, whereas the glass does not; moreover, the gel has a much less tightly packed structure than does the glass.