1. Department of Chemistry, Bioscience and Environmental Engineering, Faculty of Science and Technology, University of Stavanger, Stavanger N-4036, Norway
2. Laboratoire Softmat, Université de Toulouse, CNRS UMR 5623, Université Toulouse III─Paul Sabatier, Toulouse F-31062, France
3. Division of Material Science, Graduate School of Science and Technology, Nara Institute of Science and Technology, 8916-5 Takayama-cho, Ikoma 630-0192, Nara, Japan