1. Charles University in Prague, Faculty of Mathematics and Physics, Department of Condensed Matter Physics, 121 16 Prague 2, Czech Republic
2. Charles University in Prague, Faculty of Mathematics and Physics, Department of Macromolecular Physics, 180 00 Prague 8, Czech Republic
3. Faculty of Chemical Engineering, Institute of Chemical Technology Prague, 166 28 Prague 6, Czech Republic
4. Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic, 162 06 Prague 6, Czech Republic