1. Department of Physics and Nanoscience Center, University of Jyvaskyla, P.O. Box 35, FI-40014 Jyvaskyla, Finland
2. Department of Chemistry and Nanoscience Center, University of Jyvaskyla, P.O. Box 35, FI-40014 Jyvaskyla, Finland
3. Imatra Research Centre, Stora Enso Oyj, Tainionkoskentie 115, 55800 Imatra, Finland
4. Laboratory of Packaging Technology, Lappeenranta University of Technology, P.O. Box 20, 53851 Lappeenranta, Finland
5. ITMO University, Kronverkskii ave. 49, 197101 Saint Petersburg, Russia