The Interaction of Gelatin Molecule with Surface Active Ions

Abstract

Abstract The action of dodecyl amine hydrochloride and sodium dodecyl sulphate on gelatin was studied at various hydrogen ion concentrations of the mixed solution, once by determining the combined detergent ions to the precipitated gelatin and then measuring flow properties of mixed solutions. The determination of the combined deter-gent ions showed that the complex formation between detergent and gelatin should have taken place according to the mechanism proposed by Pankhurst and his co-workers. The non-Newtonian flow character of gelatin solution at pHs on both sides of the isoionic point, was greatly influenced by the addition of detergent cations or anions and the flow of the mixed solutions directly before the precipitate formation or after the precipitate dissolution became approximately Newtonian, which suggested that the gelatin molecule would have been brought into a more folded state by the successive combinations of detergent ions. The viscosity coefficient as well as yield value of the gelatin solution at the isoionic point were found to increase by the addition of detergent cations or anions. This suggested that the folded isoionic gelatin molecule would have been expanded by the combination with either one of the detergent ions.