Stability and cathodic electrophoretic deposition of polystyrene particles pre-coated with chitosan-alginate multilayer

The electrophoretic deposition of particles functionalized with self-assembled biocompatible polymers on stainless steel was investigated with the objective to develop new bioactive coatings which may be used in different applications such as opto-electronics, biosensors or medical applications. Alternate layers of chitosan and alginate were first adsorbed on monodispersed polystyrene colloidal particles using the layer-by-layer technique. The build-up of the polyelectrolyte films was followed by electrophoretic mobility measurements. The stability of the multilayered structure was then investigated after each adsorption step by following the change of particle zeta potential consecutive to the exposure of diluted suspensions at pH and salt conditions different from those used during the adsorption procedure. Therefore, the best experimental conditions (pH, number of layers, particle concentration) were determined in order to maintain a good stability of the preformed chitosan/alginate films after dilution for the electrophoretic deposition experiments. In these conditions, zeta potential of the core-shell particles was kept constant when exposed under an electric field which was a key factor for successful electrophoretic deposition of core-shell particles on steel surface with high coverage. Moreover the feature of final deposits was strongly correlated to the stability of the multilayer film. (C) 2016 Elsevier B.V. All rights reserved.