1. a Department of Physics , University of Connecticut , Storrs , CT , 06269
2. b Department of Chemical, Materials & Biomolecular Engineering , University of Connecticut , Storrs , CT , 06269
3. c Institute of Materials Science , University of Connecticut , Storrs , CT , 06269
4. d Department of Chemistry and the Polymer Program , University of Connecticut , Storrs , CT , 06269 E-mail: