1. Department of Mechanical and Materials Engineering and Nebraska Center for Materials and Nanoscience University of Nebraska‐Lincoln Lincoln NE 68588 USA
2. Department of Chemistry University of Nebraska‐Lincoln Lincoln NE 68588 USA
3. State Key Laboratory for Mechanical Behavior of Materials Xi'an Jiaotong University Xi'an 710049 China
4. Department of Materials Science and Engineering College of Engineering Key Laboratory of Polymer Chemistry and Physics of Ministry of Education Peking University Beijing 100871 China