1. Department of Materials Science & Engineering, Seoul National University, San 56-1, Sillim 9-dong, Gwanak-gu, Seoul 151-744, Korea
2. Department of Bioinspired Science, Ewha Womans University, Daehyun-dong, Seodaemun-gu,
Seoul 120-750, Korea
3. Department
of Chemistry, Yonsei University, Sinchon-dong,
Seodaemun-gu, Seoul
120-749, Korea
4. Department
of Material and Life
Science, Graduate School of Engineering, Osaka University, ALCA, Japan Science and Technology Agency (JST), Suita, Osaka 565-0871,
Japan