1. Werkstoffe
der Elektrotechnik and CENIDE, University Duisburg-Essen, Bismarckstraße
81, 47057 Duisburg, Germany
2. Center for Nanoparticle
Research, Institute for Basic Science (IBS), Seoul 08826, Republic of Korea
3. School
of Chemical and Biological Engineering and Institute of Chemical Processes, Seoul National University, Seoul 08826, Republic of Korea