Polyelectrolyte overcharging

The initial step of any multilayer formation model is the surface overcharge as a result of one polyelectrolyte layer adsorption. Only in this case the adsorption of the second oppositely charged polyion/surfactant ion layer is possible [9], In our work the negatively charged surface... 

The comparison of results of the SDS adsorption on the CSDAPM and PDADMAC preadsorbed layers shows that in the second case the adsorption of anionic surfactant also leads to the overcharge of the surface and increases with the increasing of surfactant concentration. Whereas the time of SDS adsorption on different polyelectrolytes is various. For example, when SDS 10 4M adsorbs on... 

The second hydrophilic slab extends up to 8 nm and contains a much lower segment density (0.1 to 1 per lipid). It is not observed for low-molecu-lar-weight PSS (Mw 4300 Da) and is hardly observed for low salt. Its thickness decreases on film compression toward 2 nm. Qualitatively this thickness decrease can be understood in terms of residual electrostatic interactions between the surface and the polyelectrolyte tails—on compression surface overcharging is reduced and hence the lowered repulsion (from head+PSS in the first slab) enables condensation of the remaining segments in the adjacent slab. 

Holappa S, Kantonen L, Andersson T, Winnik F, Tenhu H (2005) Overcharging of polyelectrolyte complexes by the guest polyelectrolyte studied by fluorescence spectroscopy. Langmuir 21 11431-11438. doi 10.1021 fla051866r... 

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