1. Department of Physical Chemistry, University of Chemistry and Technology Prague, Technická 5, CZ-166 28 Prague 6, Czech Republic
2. Institute of Macromolecular Chemistry, Czech Academy of Sciences, Heyrovského nám. 2, CZ-162 06 Prague 6, Czech Republic
3. Institute of Physics, Czech Academy of Sciences, Na Slovance 2, CZ-182 21 Prague 8, Czech Republic