Viscosity of Dilute Gelatin Solutions

Abstract

THE dilute-solution viscosity method, which has been so successfully used for high polymers, has rarely been employed in studies of protein solutions, even where there is reason to expect a markedly anisodimensional molecular shape¹. The following results have been obtained on the dilute-solution viscosity of gelatin, as part of a programme of work on the molecular weight and molecular weight distribution. The reduced viscosity (1/c·log_e(ηr)) of very dilute ash-free² solutions of gelatin (gelatin concentration 0.20 per cent and less) have been measured as a function of pH (range pH 0.50–12.5) and concentration of added electrolyte (range zero to 1.00 M sodium chloride) at 35.0° C. in standard U-tube visco-meters. The results for an alkali-treated calfskin gelatin of good quality, isoelectric point pH 5.08, are given in the accompanying graph.