Kovtun G. Adsorption and rheological characteristics of humic acids salts solutions at the liquid-gas interface

This thesis presents the results of a systematic study of the surface properties of solutions of sodium salts of humic acids at the liquid-gas interface by tensiometry and surface dilatational rheology. It is shown that salts of humic acids are characterized by a nondiffusion adsorption mechanism, the equilibrium surface tension and limiting elasticity are in good agreement with the bilayer adsorption model of polyelectrolytes of protein nature. The regularities of the influence of electrolytes (HCl and NaCl), nonelectrolytes (lower alcohols and acetone), cetyltrimethylammonium bromide additives on the adsorption and surface rheological properties of sodium humates are established, possible mechanisms for the formation of mixed adsorption layers are suggested. Analysis of the properties of individual solutions and mixtures is held from the same positions in the framework of unified theoretical models. The possibility of sodium humate to stabilize foams and emulsions is substantiated.