Date of Award
Bachelor of Science
Von Weimarn has shown that the degree of supersaturation at the time of formation, and the viscosity of the medium account, qualitatively at least, for the resulting character of the precipitate from a solution, whether it be crystalline of amorphous. When fairly concentrated solutions form precipitates they are usually colloidal in nature and may even be gelatinous, or a jelly may be formed. When a precipitate, thus formed, retains an appreciable quantity of the liquid in which it was dissolved in the form of a semi-rigid mass, it is termed a “gelatinous precipitate”, and if all the liquid is initially retained a jelly or gel is produced. In the latter case Von Weimarn’s ratio, P/L = U, is very high or the percentage supersaturation at the beginning of the precipitation is very large. Where P = the instantaneous concentration, L = the solubility of coarse crystals, U = the percentage supersaturation at the beginning of precipitation.
Gimber, David John, "The effect of polyvalent electrolytes on the viscosity of silicic acid gel mixtures" (1946). Honors Theses. 1905.