1. Department of Chemical Engineering, University of Pretoria, 0002 Pretoria, South Africa
2. Leibniz-Institut für Polymerforschung Dresden e.V., Institute of Polymer Materials; Processing Technology, D-01069 Dresden, Germany
3. Department of Chemistry, University of Pretoria, 0002 Pretoria, South Africa
4. Institute of Physical Chemistry, Universität Stuttgart, Stuttgart D-70569, Germany