1. Polymer Materials Fusion Research Center & Department of Polymer-Nano Science and Technology, Chonbuk National University, Jeonju 561-756, Korea
2. Department of Materials Science and Optoelectronic
Engineering, National Sun Yat-Sen University, Kaohsiung 804, Taiwan
3. Department of Polymer Science, The University of Akron, Akron, Ohio 44325-3909, United States