1. Department of Chemistry, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology, Teknikringen 30, Stockholm SE-100 44, Sweden
2. RISE Research Institutes of Sweden, Chemistry, Materials and Surfaces, Box 5607, Stockholm SE-114 86, Sweden
3. School of Chemistry, University of New South Wales, Sydney, New South Wales 2052, Australia
4. Laboratoire de Tribologie et Dynamique des Systèmes, École Centrale de Lyon, Ecully Cedex 69134, France