1. Department of Polymer Science and Engineering; University of Massachusetts Amherst; 120 Governors Drive Amherst MA 01003 USA
2. School of Chemistry and Chemical Engineering; Shanghai Jiao Tong University; 800 Dongchuan Road Shanghai 200240 P. R. China
3. Department of Mechanical and Industrial Engineering; University of Massachusetts Amherst; 160 Governors Drive Amherst MA 01003 USA