1. Department of Chemical Engineering and Department of Mechanical Engineering, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands, Institute of Polymer Technology and Materials Engineering (IPTME), Loughborough University, Loughborough, LE11 3TU, United Kingdom, DUBBLE CRG/ESRF, Netherlands Organization for Scientific Research (NWO), c/o ESRF BP 220, F-38043, Grenoble Cedex, France, Dutch Polymer Institute (DPI), PO Box 902, 5600 AX Eindhoven, The Netherlands