1. Department of Applied Chemistry, Faculty of Science and Engineering, Waseda University, Ohkubo‐3, Shinjuku‐ku, Tokyo 169‐8555 (Japan), Fax: (+81) 3‐5286‐3199
2. Materials and Chemical Engineering, Faculty of Textile Science and Technology, Shinshu University, Tokida‐3, Ueda, Nagano 386‐8567 (Japan)
3. Kagami Memorial Research Institute for Materials Science and Technology, Waseda University, Nishiwaseda‐2, Shinjuku‐ku, Tokyo 169‐0051 (Japan)
4. World Premier International (WPI) Research Center for Materials, Nanoarchitectonics (MANA), National Institute for Materials Science (NIMS), Namiki‐1, Tsukuba, Ibaraki 305‐0044 (Japan)