Affiliation: | 1. School of Chemistry &2. Physics, University of KwaZulu-Natal, Scottsville, South Africa;3. Department of Physics, Faculty of Science and Technology, Omdurman Islamic University, Omdurman, Sudan;4. Department of Physics, Addis Ababa University, Addis Ababa, Ethiopia;5. School of Chemistry, Shoolini University, Solan, India;6. College of Materials Science and Engineering, Shenzhen Key Laboratory of Polymer Science and Technology, Nanshan District, Shenzhen University, Shenzhen, People's Republic of China |