1. School of Materials and Engineering, Southwest Petroleum University, Chengdu, Sichuan 610500, China
2. State Key Lab of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu, Sichuan 610050, China
3. Polymer Program, Institute of Materials Science and Department of Chemical & Biomolecular Engineering, University of Connecticut, Storrs, Connecticut 06269, United States