1. Gh. Asachi Technical University, Faculty of Industrial Chemistry, Department of Macromolecules, Bd. D. Mangeron, No. 71, 6600 Iasi, Romania
2. Gh. Asachi Technical University, Faculty of Industrial Chemistry, Department of Macromolecules, Bd. D. Mangeron, No. 71, 6600 Iasi, Romania,
3. Gh. Asachi Technical University, Faculty of Materials Science, Department of Physics, Bd. D. Mangeron, No. 71, 6600 Iasi, Romania