Electrostatic self-assembled nanoarchitectures between polycations of integral type and azo dyes

The electrostatic self-assembling was successfully used to build-up new polycation/azo dye multilayers starting from a polycation of integral type containing 95 mol.% of N,N-dimethyl-2-hydroxypropyleneammonium chloride units in the main chain (PCA5) and two multicharged azo dyes: Direct Blue 1 (DB1) and Direct Red 80 (DR80). The build-up and the stability of the PCA5/azo dyes layered thin films, in dependence on the adsorption conditions and the dye structure, were followed by UV–Vis spectroscopy, the variation of the ζ potential in dependence on pH and by spectroscopic ellipsometry. The multilayer build-up in the presence of the neutral salts was correlated with the counterion influence on the macroion conformation. The surface charge and the pH corresponding to the isoelectric point were depending on the polycation adsorption conditions.