1. a Maurice Morton Institute of Polymer Science The University of Akron , Akron , OH , 44325-3909 , USA
2. b Kossuth Lajos University, Department of Physical Chemistry , P.O. Box 7, H-4010 , Debrecen , Hungary
3. c Central Research Institute for Chemistry of the Hungarian Academy of Sciences , P.O. Box 17, H-1525 , Budapest , Hungary