1. Paulo Scarpa Polymer Laboratory (LaPPS), Chemistry Department, Federal University of Parana; POB 19081 81531-990, Curitiba, Paraná Brazil
2. Institute of Physics; Physics Department, São Paulo University; POB 369 13084-971, São Carlos, São Paulo Brazil
3. Physics Department; Federal University of São Carlos; São Carlos, São Paulo, POB 676, 13565-905 Brazil
4. Physic Academic Department; State University of Londrina; Londrina, Paraná, 86057-970 Brazil