1. School of Materials Science and Engineering and Tianjin Key Laboratory of Molecular Optoelectronic Science
2. Tianjin University
3. Tianjin 300072
4. P. R. China
5. State Key Laboratory of Polymer Physics and Chemistry
6. Changchun Institute of Applied Chemistry
7. Chinese Academy of Sciences
8. Changchun
9. Joint School of National University of Singapore and Tianjin University