1. Institute of Macromolecular Compounds; 31, Bolshoi pr. Saint-Petersburg 199004 Russia
2. Department of Physics; St. Petersburg State University, Ulyanovskaya Str. 1; Petrodvorets, St Petersburg 198504 Russia
3. Theory of Polymers and Soft Matter, Department of Applied Physics; Technische Universiteit Eindhoven; 5600 MB Eindhoven The Netherlands