1. CSIR (Council for Scientific and Industrial Research); Materials Science and Manufacturing; Polymers and Composites Competence Area, Gomery Avenue, P.O. Box 1124 Port Elizabeth 6000 South Africa
2. University of the Free State (Qwa-Qwa Campus); Department of Chemistry; Private Bag X13 Phuthaditjhaba 9866 South Africa
3. Nelson Mandela Metropolitan University (NMMU); Department of Chemistry, University Way; P.O. Box 1600 Port Elizabeth 6000 South Africa