The variation of the viscosity of gelatin sols with temperature

Abstract

AbstractThe variation of the viscosity with temperature has been studied on sols of an isoelectric ossein gelatin, and representation of this variation has been found possible by means of an equation of the type ν = AeK/T.The term A has been shown to be a function of the percentage (weight) concentration of gelatin in the sol.A working hypothesis has been made that the hydration of the gelatin particles, during soaking, persists on dispersion; the decrease in viscosity with rising temperature is represented as due, in the main, to a progressive loss of the absorbed water back to the free dispersion medium, thereby decreasing the ratio of weight of dispersed phase to weight of dispersion medium.Expression of the viscosity as a function of this ratio had yielded an equation representing the variation of the viscosity with concentration of gelatin.The reversibility of the viscosity‐temperature variation has been explained as being due to the rupture and subsequent re‐formation of hydrogen bonds set up between the water molecules and the lyophilic peptide groups in the gelatin particles.