Layer-by-Layer Films Constructed by the Assembly of Strong Polyelectrolytes and their Hydrophobically-Modified Derivatives

摘要

The layer-by-layer self-assembly of polyelectrolytes is a powerful and robust strategy in material science and biotechnology to construct surfaces with specific properties, starting from readily available polyelectrolytes The construction of multilayers has been analyzed in great detail, leading to a set of general guidelines which allow one to design functional films of great complexity The properties of the multilayers are partially determined by the conformation of the polyanion and polycation in the solution used in the buildup procedure. The aim of the work described here was to assess the effect of the polyelectrolyte conformation, from a compact globule to an extended chain, on multilayer growth and properties. Thus, we set about to monitor the construction of multilayers formed by the strong polycation poly(diallyl dimethylammonium chloride) (PDADMAC) and either the strong polyanion, poly(sodium 2-acrylamido-2-methylpropanesulfate) (PAMPS) or its hydrophobically-modified derivatives (HM-PAMPS). The latter polyanions are known to form single chain micelles or "unimers" of varying compactness, depending on the level of substitution, the nature of the hydrophobic group, and the solution ionic strength We present here a study by quartz crystal microbalance with dissipation (QCM-D), surface plasmon resonance (SPR), and atomic force microscopy (AFM) of multilayers of PDADMAC and HM-PAMPS (Fig. 1).