SURFACE TENSION AND ASSOCIATION IN AQUEOUS SOLUTION SURFACTANTS IN THE PRESENCE OF POLYACRYLAMIDE

The surface tension of aqueous solutions of cationic (dodecylammonium and dodecylpyridinium chlorides) and anionic (sodium dodecylsulfate) surfactants was measured in the presence of polyacrylamide in the solution.  A synergistic effect of reducing the surface tension of mixed solutions of cationic surfactants, in the region of sufficiently high concentrations of mixed solutions of sodium dodecyl sulfate, with polyacrylamide in the range of molar ratios of the mixture components - n (Surfactants : PAA) = 1: 1; 1: 0.25 was established. The values ​​of the maximum adsorption, the values ​​of the area per molecule or associate of surfactants in the adsorption layer, as well as the standard Gibbs free energy of adsorption of surfactant - PAA associates are calculated. In accordance with Rosen's model, the composition of mixed adsorption layers at the solution-air interface is calculated, as well as the parameter of intermolecular interaction in adsorption layers between molecules, cationic and anionic ions surfactants and PAA. The values ​​of the critical micelle concentration (CMC) of individual surfactants in aqueous solutions exceed the CMC of the studied surfactants in the presence of PAA, which promotes micelle formation.