1. Carbon Composite Materials Research Center, Institute of Advanced Composite Materials, Korea Institute of Science and Technology, Chudong-ro 92, Bondong-eup,
Wanju-gun, Jeollabuk-do 565-905, Republic of Korea
2. School of Materials Science and Engineering, Gwangju Institute of Science and Technology (GIST), 261 Cheomdan-gwagiro, Buk-Gu, Gwangju 500-712, Republic of Korea
3. Department of Chemical Science and Engineering, Tokyo Institute of Technology, 2-12-1-E4-5,
Ookayama, Meguro-ku, Tokyo 152-8552, Japan