On the Way to Functional Coatings: Polyelectrolyte Multilayers

E. GUZMAN; H. RITACCO; F. ORTEGA; R. G. RUBIO

Granada

Congreso; III Reunión Ibérica de coloides e Interfases (RICI); 2009

Universidad de Granada

Nanostructured materials are nowadays a fundamental field of research with implications in many important present and future applications. Self-assembled multilayers are among this type of materials. One of the most versatile and promising techniques for constructing functionalized thin layers is the layer-by-layer (LbL) method. In this method charged materials are used sequentially to build-up multilayers by self-assembly. Since the pioneering work of Decher et al., who used polyelectrolytes of opposite charges as building blocks in the multilayer assembly, the list of possible construction components has increased enormously: biopolymers, colloidal particles, carbon nanotubes and microgels. Furthermore, the method is not limited to materials with charged groups like strong polyelectrolytes, making it possible to build multilayers based on other types of interactions such as acid–base reactions of weak polyelectrolytes6 or hydrogen bonds. An advantage of the LbL method compared to other techniques, like the Langmuir-Blodgett,8 is that LbL multilayers can be built-up on substrates other than flat ones, e.g. colloidal particles or fluid interfaces. In this work, we have carried out a multi-technique study of the changes on layer thicknesses as a function of the number of layers constructed in different ionic strength conditions. The mechanism of multilayer growth, its water content, the mechanical properties and the kinetics of layer adsorption will be discussed.