1. School of Chemistry and Physics; University of KwaZulu-Natal, Westville Campus; Private Bag X54001 Durban 4000 South Africa
2. Department of Applied Chemistry; University of Johannesburg; P.O. Box 17011, Doornfontein Johannesburg 2028 South Africa
3. School of Electrical, Electronic and Computer Engineering; University of KwaZulu-Natal; King George V Avenue Durban 4014 South Africa