Dynamic surface elasticity of mixed poly(diallyldimethylammonium chloride)/sodium dodecyl sulfate/NaCl solutions

The non-monotonic concentration and kinetic dependencies of the dynamic dilational surface elasticity of mixed poly(diallyldimethylammonium chloride)/sodium dodecyl sulfate(SDS)/NaCl solutions indicate the formation of micro-aggregates in the surface layer. The increase of the solution's ionic strength results in strong changes of the surface dilational rheological properties and thereby of the interfacial layer structure at lower SDS concentrations due to the large increase of the adsorption rate. Close to the charge match point of the components, however, the rheological properties are influenced by the presence of micro-aggregates embedded in the adsorption layer. In this case, effects of changing the sample history on the rheological behavior and heterogeneity of the interface were further investigated. (C) 2014 Elsevier B.V. All rights reserved.