Ultrathin multilayers made by alternate deposition of ionenes and polyvinylsulfate: from unstable to stable growth

We report on the influence of ionic strength of polyelectrolyte solutions on the growth of multilayers made of polyvinylsulfate and a series of aromatic ionenes of decreasing charge density. Stable multilayers growth was only possible for polyelectrolytes of sufficiently high charge density, confirming the existence of a critical charge density for the formation of multilayers. We also show that, for systems near the critical charge density, the addition of salt to the solution may result in a transition from unstable to stable multilayer growth. (C) 1998 Elsevier Science S.A. All rights reserved