1. Department of Chemistry; Federal University of São Carlos; Rod. Washington Luís km 235 13560-970 São Carlos, SP Brazil
2. Carbon Sci-Tech Labs; School of Electrical and Computer Engineering; University of Campinas; Av. Albert Einstein 400 13083-852 Campinas-SP Brazil
3. National Institute for Space Research; Av. dos Astronautas 1758 12227-010 São José dos Campos, SP Brazil