1. Istituto per lo Studio delle Macromolecole (CNR), Via E. Bassini 15, I-20133 Milano, Italy
2. Istituto di Chimica e Tecnologia dei Polimeri, Sez. Catania (CNR), Dipartimento di Chimica, Università di Catania, Viale A. Doria 6, I-95125 Catania, Italy
3. RIKEN (The Institute of Physical and Chemical Research), Hirosawa 2-1, Wako, Saitama, 351-0198, Japan
4. Kanagawa Academy of Science and Technology, KSP East 309, Sakado 3-2-1, Takatsu-ku, Kawasaki, Kanagawa 213-0012, Japan, and RIKEN (The Institute of Physical and Chemical, Research), Hirosawa 2-1, Wako, Saitama 351-0198, Japan