1. Department of Chemistry, Fribourg University, Chemin Du Musée 9, 1700 Fribourg, Switzerland
2. Swiss National Center for Competence in Research (NCCR) Bio-inspired Materials, University of Fribourg, Chemin des Verdiers 4, CH-1700 Fribourg, Switzerland
3. Department of Chemical, Paper, and Biomedical Engineering, Miami University, Oxford, Ohio 45056, USA