1. Department of Chemistry, Addis Ababa University
2. Addis Ababa
3. Ethiopia
4. Institute for Materials Research (IMO-IMOMEC), Hasselt University
5. B-3590 Diepenbeek
6. Department of Chemistry, Ambo University
7. Ambo
8. X-LAB, Hasselt University, Universitaire Campus
9. Belgium
10. Physical Chemistry and Polymer Science (FYSC), Vrije Universiteit Brussel (VUB)
11. B-1050 Brussels
12. Department of Chemistry and Chemical Engineering, Chalmers University of Technology
13. SE-412 96 Götenborg
14. Sweden