1. Empa, Swiss Federal Laboratories for Materials Science and Technology, 8600 Dübendorf, Switzerland
2. Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
3. Organic and Carbon Nanomaterials Unit, Okinawa Institute of Science and Technology Graduate University 1919-1 Tancha, Onna-son, Kunigami-gun, Okinawa 904-0495, Japan
4. Department of Chemistry and Biochemistry, University of Bern, 3012 Bern, Switzerland