Low Temperature Studies with Colloidal Silicic Acid

Abstract
1. 1. Silica sols prepared with mineral acids and with ion-exchange resins have been frozen at −15°, −25°, −35°, −45°, −55°, −65°, and −190°C. 2. 2. The effects of hydrogen-ion concentration, rate of thawing, temperature of aging the frozen systems, and presence of electrolytes were investigated. 3. 3. The following factors were found to increase the stability of the systems: (a) low temperature of freezing, (b) low temperature of aging, (c) rapid rate of thawing, and (d) presence of lithium chloride and calcium chloride.