1. “I.G.Murgulescu” Institute of Physical Chemistry, Romanian Academy, Splaiul Independentei 202, 77208 Bucharest, Romania
2. Institute of Materials, Tampere University of Technology, P.O. Box 541, FIN-33101 Tampere, Finland
3. Department of Chemistry, University of Jyvaskyla, P.O. Box 35, SF-40351 Jyvaskyla, Finland