1. Institute of Physics, University of Silesia in Katowice, SMCEBI, 75 Pułku Piechoty 1A, Chorzow 41-500, Poland
2. Faculty of Physics, A. Mickiewicz University, ul. Uniwersytetu Poznańskiego 2, 61-614 Poznań, Poland
3. Leibniz Institute of Polymer Research Dresden, Hohe Strasse 6, D-01069 Dresden, Germany