The basis of this work and the progress on an outline understanding is described elsewhere on the website. Although the model described there gives a successful overview of the interfacial behaviour of these mixture, there remain many details that are not understood and which are essential for devising a sound basis for the incorporation of these mixtures into formulations.
The roles of size and type of polymer, surfactant head group, added electrolyte, atc. have been partially evaluated. However, there is one important feature that is not understood and that is the role of the hydrophobic interaction in the assembly of the layered surface complex. That this is important is shown by the effects of pH on the interaction of the two weak polyelectrolytes, PEI (poly(ethylene imine)) and PAA (poly(acrylic acid)). The interaction of these two polymers with ooppositely charged surfactants is not reduced when the pH is adjusted to make them neutral as much as one might expect. We continue to explore this with some oligomeric amines. This work is supported as part of the EPSRC project on Surfactant Multilayers.