1. Department of Chemistry, Faculty of Science, Al-Azhar University, Cairo, Egypt;
2. Egyptian British Co. for Chemicals, Giza, Egypt;
3. Polymeric Materials Research Department, Advanced Technology & New Materials Research Institute (ATNMRI), City of Scientific Research and Technological Applications (SRTA-City), Alexandria, Egypt;
4. Nanotechnology Research Center (NTRC), The British University in Egypt (BUE), Cairo, Egypt