1. Materials
Science and Engineering Program, University of California San Diego, 9500 Gilman Drive, La Jolla, California 92037, United States
2. Department
of Chemistry and Biochemistry, University of California San Diego, 9500 Gilman Drive, La Jolla, California 92037, United States
3. College
of Polymer Science and Engineering, State Key Laboratory of Polymer
Materials Engineering, Sichuan University, Chengdu 610065, China
4. Department
of Nanoengineering, University of California San Diego, 9500 Gilman
Drive, La Jolla, California 92037, United States
5. Electron
Microscopy Core Facility, University of California San Diego, 9500 Gilman Drive, La Jolla, California 92037, United States