[1] Univ Fed Sao Carlos, Dept Chem, BR-13565905 Sao Carlos, SP, Brazil
[2] Brazilian Agr Res Corp Embrapa, Natl Nanotechnol Lab Agr, 15 Novembro St 1452, Sao Carlos, SP, Brazil
[3] Max Planck Inst Colloids & Interfaces, Dept Colloid Chem, Muhlenberg 1, D-14476 Potsdam, Germany
[4] Univ Fed Minas Gerais, Dept Chem, BR-35400000 Belo Horizonte, MG, Brazil
[5] Univ Fed Minas Gerais, Dept Phys, BR-31270901 Belo Horizonte, MG, Brazil