1. Centre of Polymer Systems, Tomas Bata University in Zlín, Trida Tomase Bati 5678; Zlín 760 01 Czech Republic
2. Department of Chemistry, Faculty of Science; Ain Shams University, Abbassia; Cairo 11566 Egypt
3. Polymer Institute, Slovak Academy of Sciences, Dúbravská cesta 9; Bratislava Slovakia 845 41
4. Department of Polymers; National Center for Radiation Research and Technology, Atomic Energy Authority, Nasr City; Cairo 11371 Egypt
5. Faculty of Mathematics and Physics; Charles University Prague, V Holesovickach 2; Prague 8 18000 Czech Republic