1. Institute of Polymers, Bulgarian Academy of Sciences, “Akad. G. Bonchev” St., Bl. 103-A, 1113 Sofia, Bulgaria
2. Institute of Molecular Biology, Bulgarian Academy of Sciences, “Akad. G. Bonchev” St., Bl. 21, 1113 Sofia, Bulgaria
3. Centre of Polymer and Carbon Materials, Polish Academy of Sciences, Marie Curie-Sklodowskiej 34, 41-819 Zabrze, Poland