1. Department of Colloid Chemistry, Department of Physical Chemistry, Department of Organic Chemistry, and Nanostructured Materials Research Group of the Hungarian Academy of Sciences, University of Szeged, H-6720 Szeged, Hungary, Department of Atomic Physics, Budapest University of Technology and Economics, H-1521 Budapest, Hungary, and Institute of Materials Science, NCSR “DEMOKRITOS”, GR-15310 Athens, Greece