1. Beijing National Laboratory for Molecular Sciences (BNLMS); Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education; Key Laboratory of Polymer Chemistry and Physics of Ministry of Education; Center of Soft Matter Science and Engineering; College of Chemistry and Molecular Engineering; Peking University; Beijing 100871 China
2. Department of Mechanical Engineering; State Key Laboratory of Tribology; Tsinghua University; Beijing 100084 China
3. Department of Chemical Engineering; Stanford University; Stanford CA 94305 USA