1. Materials Science Department, Institute of Graduate Studies and Research (IGSR), Alexandria University, 163 Horrya Avenue, Shatby, P.O. Box 832, Alexandria 21526, Egypt
2. The Egyptian Ethylene and Derivatives Company (Ethydco), Alexandria 21544, Egypt
3. School of Chemistry and Chemical Engineering, Queen’s University Belfast, Belfast BT9 5AG, Northern Ireland, UK