1. Department of Polymer Technology, Chalmers University of Technology, SE-412 96 Göteborg, Sweden; Department of Applied Physics, Chalmers University of Technology, SE-412 96 Göteborg, Sweden; Imego Institute, Aschebergsg. 46, SE-411 33 Göteborg, Sweden; and Department of Chemistry & Materials Technology, SP Swedish National Testing and Research Institute, 50115 Borås, Sweden