Much has been learnt in the past 3 decades about Langmuir  Monolayers due to the introduction of new techniques, namely optical microscopy and surface X-Ray diffraction, later FTIR spectroscopy. This led to the notion of a richness of phases as well as to peculiar domain structures due to long-range electrostatic forces arising at interfaces. Extending these studies to more complex films of biological molecules this could contribute much to the understanding of processes at membrane surfaces. However, it also demonstrated that films built up from these monolayers have a complex domain structure and in case of �perfect� organization do not dissolve functional molecules. Functional organized films therefore require alternatives to the Langmuir-Blodgett technique, and one of the most promising is �Layer-by-Layer-Assembly�. With this technique one adsorbs alternatingly molecules, ions or particles of opposite charge , and this leads to multilayers of defined thickness and roughness with precision of nm.The structure is well characterized by X-Ray-,Neutron and light reflectivity, the permeation by optical spectroscopy. Due to the high modularity and versatility of the process multifunctional films can be build up, promising many applications in Bio- and materials sciences. As the technique relies on adsorption also curved and porous solids can be coated, and one thus obtains functional colloids. Selecting sacrificial cores one further obtains micro- and nanocapsules with well-defined walls. Controlling the intermolecular interactions inside these walls one can control their permeability and mechanical properties. This has been achieved via changes of pH, temperature, salt, electrochemical potential or chemical reactions as well as via external light, microwaves or acoustic fields, as will be demonstrated by optical and force spectroscopic studies. The processes are at least qualitatively understood and quantitatively controlled, so that they now invite many different applications. Examples on this to be presented vary from light triggered intracellular release of a signal peptide to follow an immune reaction to release of anticorrosion agents to fabricate a self-repairing coating.

From Langmuir monolayers to layer-by-layer assembly

248th National Meeting (2014)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.