[1] Beijing Univ Chem Technol, Coll Mat Sci & Engn, Beijing Adv Innovat Ctr Soft Matter Sci & Engn, Beijing 100029, Peoples R China
[2] Univ Massachusetts, Dept Polymer Sci & Engn, Amherst, MA 01003 USA
[3] Lawrence Berkeley Natl Lab, Div Mat Sci, 1 Cyclotron Rd, Berkeley, CA 94720 USA