Stabilization of Silver Iodide Sol Particles by Acetate and N-Succinyl of Chitosan

Abstract

This article studies the regularities of stabilization of colloidal particles of silver iodide (AgI) sols by polymeric stabilizers: chitosan acetate (ACTZ) and the sodium salt of chitosan N-succinyl (SCTZ). The relevance of the study is due to the fact that the creation of stable polymer-colloidal dispersions (PCDs) based on water-soluble derivatives of chitosan and inorganic colloidal particles with antiseptic properties is one of the ways of creating hybrid gel-like and film materials for biomedical purposes. It is proved that in the presence of chitosan acetate polycation with a concentration of 0.1 wt % the adsorption of similarly charged macroions on the particles of the dispersed phase leads to an increase in the stability of the AgI sol with positively charged colloidal particles by measuring the electrokinetic potential. The AgI sol with positively charged particles is recharged and the electrokinetic potential of the AgI sol with negatively charged particles increases with a simultaneous increase in the aggregative stability of the sols in the presence of a polyanion (SCTZ sodium salt). Using potentiometric titration, it is shown that the increase in the aggregative stability of silver iodide sols at higher concentrations of ACTZ and SCTZ is associated more with the increase in the viscosity of the solution as the polymer concentration increases (structural-mechanical barrier according to Rebinder) rather than the adsorption of macromolecules on the sol surface. The optical spectroscopy and viscometry data indicate that the mixing of silver iodide sols with solutions of polymers of ACTZ and SCTZ is accompanied by the formation of stable PCDs, whose components which interact with each other, and do not represent mechanical mixtures of a polymer solution and a colloidal solution.