1. Polymer Department; National Institute of Research and Development in Chemistry and Petrochemistry; 202 Splaiul Independentei Bucharest 060021 Romania
2. Advanced Polymers Materials Group, Politehnica University of Bucharest; 1-7 Polizu Street Bucharest 011061 Romania
3. C. D. Nenitescu Organic Chemistry Center of Romanian Academy; 202 B Splaiul Independentei Bucharest 060023 Romania
4. Physics Department, Faculty of Applied Sciences; Politehnica University of Bucharest; 313 Splaiul Independentei Bucharest 060042 Romania