1. Nanotechnology and Water Sustainability (NanoWS) Research Unit, College of ScienceEngineering and Technology (CSET), University of South Africa, Corner of Christiaan De Wet and Pioneer Avenue, Florida Roodepoort 1709 South Africa
2. Institute for Nanotechnology and InnovationDepartment of Chemistry, Rhodes University PO Box 94 Grahamstown, 6140 South Africa