Dynamic surface elasticity of polyelectrolyte solutions

Oscillating bubble and drop methods were applied to aqueous solutions of poly(dimethyldiallylammonium chloride) and copolymers of sodium 2acrylamido-2-methyl-1-propansulfonate with acryl amide and N-isopropylacrylamide at various concentrations and ionic strengths. The dynamic surface elasticity was measured as a function of the surface age and non-monotonic kinetic dependencies were observed for some systems. Although solutions of different polyelectrolytes displayed various types of the surface viscoelastic behavior, they all differed strongly from the surface dilational viscoelasticity of non-ionic polymer solutions. At the same time some distinctions with the surface dilational viscoelasticity of sodium poly(styrenesulfonate) solutions were discovered too. They are a consequence of the specific structure of the PSS adsorption films as it had been assumed earlier.