1. Institute of Polymer Materials, Friedrich-Alexander University Erlangen-Nürnberg, Martensstrasse 7, D-91058 Erlangen, Germany
2. School of Semiconductor and Chemical Engineering, Chonbuk National University, Baekjero 567, Deokjin-gu, Jeonju, Jeonbuk, 561-756, Republic of Korea
3. Department of Polymer Engineering, Amirkabir University of Technology, 424 Hafez Avenue, P.O. Box 15875-4413, Tehran, Iran