Deposition of polyelectrolyte multilayer films made from poly(diallyldimethyl ammonium chloride) and poly(4-styrene sulfonate): Influence of the NaCl concentration for films obtained by alternated spraying and alternated dipping

The deposition of polyelectrolyte multilayer films consists of the sequential adsorption of polycationic and polyanionic species at solid–liquid interfaces. The adsorption process can be performed either by alternated dipping of the substrate to be coated in the polyelectrolyte containing solutions, by alternated spin coating of these solutions or by alternated spraying of them. Different coating technologies can lead to different properties of the obtained coatings even for the same combination of polycations and polyanions. The aim of this article is to show that by playing on the concentration of the supporting electrolyte, NaCl, the films obtained by alternated spraying and alternated dipping grow differently and display different properties, in terms of refractive index, surface morphology, wettability for water and surface composition.