1. Department of Chemistry and Bioactive Material Sciences, Research Institute of Physics and Chemistry, Chonbuk National University, Jeonju 561-756, Korea
2. Jeonju Center, Korea Basic Science Institute, Jeonju 561-756, Republic of Korea
3. Textile Engineering, Chemistry and Science, North Carolina State University, 2401 Research Dr., Raleigh, NC 27695-8301, USA