1. Institute for Coatings and Surface Chemistry; University of Applied Sciences Niederrhein; 47798 Krefeld Germany
2. Department of Physical Chemistry and Physical Chemistry and Didactics of Chemistry; Saarland University; 66123 Saarbrücken Germany
3. Institut de Science des Matériaux de Mulhouse IS2M; UMR CNRS 7361; UHA; 15, rue Jean Starcky, 68057 Mulhouse Cedex France