Recent explorations in electrostatic multilayer thin film assembly

New developments in the area of electrostatic layer-by-layer assembly are reviewed, with emphasis on work in the past two years. Advances in fundamental understanding of polyelectrolyte adsorption is addressed, including the use of new probes and experimental techniques which examine final structure, film interpenetration, and control of thickness. Both theoretical and experimental studies of adsorption of weak polyelectrolytes have been addressed. The role of secondary interactions such as hydrogen bonding or dispersion forces on these parameters is a more recent area of focus. Molecular scale order has been achieved in layered films to produce noncentrosymmetric films; further control of the ordering of molecular side groups in these systems could lead to new and interesting electrical and optical properties. Finally, it has been shown that polyelectrolyte multilayers may be templated onto a number of surfaces; these materials can be patterned onto surfaces to make three dimensional microstructures, or grown on a sacrificial colloidal template to form encapsulant membranes.