1. Discipline of Chemical Engineering, University of KwaZulu-Natal, 238 Mazisi Kunene Road, Glenwood, Durban 4041, South Africa
2. Institute of Chemical Technology, Universität Leipzig, Linnéstr. 3, 04103 Leipzig, Germany
3. Department of Chemical Engineering, University of Pretoria, Lynnwood Road, Hatfield, Pretoria 0028, South Africa
4. Department of Chemical Sciences (Formerly Applied Chemistry), University of Johannesburg, Doornfontein Campus, P.O. Box 17011, Doornfontein 2028, South Africa
5. Centre for Nanomaterials Science Research, University of Johannesburg, Johannesburg 2000, South Africa