PHOTOINDUCED SWITCHING IN SELF-ASSEMBLED MULTILAYERS OF AZOBENZENE-CONTAINING IONENE POLYCATIONS AND ANIONIC POLYELECTROLYTES

Ultrathin molecular assemblies of new ionene polysoaps bearing azobenz ene units in the main chain and anionic polyelectrolytes have been pre pared upon electrostatic layer-by-layer adsorption on charged substrat es. Ionenes could be adsorbed in the trans- and cia-rich state of thei r azobenzene units. Use of cis-rich polymer was found to be advantageo us because up to three times more material could be adsorbed per dippi ng cycle as from the solution of the trans polymer. Alternate irradiat ion with UV (<370 nm) and visible (>450 nm) Light allowed to switch be tween the traits isomer and the cia-rich photostationary state. Photoc onversion of ionenes in multilayers is lower than in solution, but hig her than for multilayers of azobenzene bolaamphiphiles reported recent ly.