1. Department of Organic and Inorganic Chemistry Federal University of Ceara 60440‐900 Fortaleza Brazil
2. LFS – Laboratory of Surface Phenomena University of São Paulo Av. Prof. Mello Moraes 2231 05508‐970 São Paulo Brazil
3. Department of Engineering for Innovation University of Salento 73100 Lecce Italy
4. Instituto Tecnológico Vale 35400‐000 Ouro Preto Brazil