Polyelectrolytes bearing azobenzenes for the functionalization of multilayers

Thin polymeric films are assembled by the alternating adsorption of opposit ely charged polyelectrolytes. The polyions are functionalized by azobenzene s, typically carrying donor-acceptor substituents. The azobenzene chromopho res are exploited as versatile analytical tools, to study the assembling pr ocess, and to control the film quality. A high concentration of ionic group s does not seem to be advantageous per se for good film growth, but rather the matching of the charge densities of the polyelectrolyte pair used seems to be important. Also, the influence of the strongly interacting, form-ani sotropic character of the azobenzenes on the internal film structure was in vestigated. Although even high concentrations of azobenzenes and of other m esogens do not induce particular ordering, a few polymer pairs allowed the construction of real multilayer films, exhibiting e.g. Bragg peaks.