1. Department of Materials Engineering Federal Center of Technological Education of Minas Gerais (CEFET‐MG) Av. Amazonas 5253, Nova Suiça Belo Horizonte MG Brazil
2. Technology Center in Nanomaterials and Graphene Federal University of Minas Gerais (CTNano/UFMG) R. Professor José Vieira de Mendonça 520, Engenho Nogueira Belo Horizonte MG Brazil