Recent explorations in electrostatic multilayer thin film assembly

New developments in the area of electrostatic layer-by-layer assembly are r eviewed, with emphasis on work in the past two years. Advances in fundament al 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 exp erimental studies of adsorption of weak polyelectrolytes have been addresse d. The role of secondary interactions such as hydrogen bonding or dispersio n forces on these parameters is a more recent area of focus. Molecular scal e order has been achieved in layered films to produce noncentrosymmetric fi lms; further control of the ordering of molecular side groups in these syst ems could lead to new and interesting electrical and optical properties. Fi nally, it has been shown that polyelectrolyte multilayers may be templated onto a number of surfaces; these materials can be patterned onto surfaces t o make three dimensional microstructures, or grown on a sacrificial colloid al template to form encapsulant membranes. (C) 2000 Elsevier Science Ltd. A ll rights reserved.