1. College of Chemistry Key Laboratory of Green Chemistry and Technology of Ministry of Education and State Key Laboratory of Polymer Materials Engineering Sichuan University Chengdu 610065 P. R. China
2. School of Chemical Engineering and State Key Laboratory of Polymer Materials Engineering Sichuan University Chengdu 610065 P. R. China
3. State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Center of Smart Materials and Devices Wuhan University of Technology Wuhan 430070 China
4. Division of Physics and Applied Physics School of Physical and Mathematical Sciences Nanyang Technological University 21 Nanyang Link Singapore 637371 Singapore
5. National Synchrotron Light Source II Brookhaven National Lab Suffolk Upton NY 11973 USA