1. Institute of Chemistry Martin Luther University Halle‐Wittenberg Kurt‐Mothes‐Strasse 2 Halle/Saale D‐06120 Germany
2. Department of Materials Science and Engineering University of Sheffield Sheffield S1 3JD UK
3. State Key Laboratory for Mechanical Behavior of Materials Shaanxi International Research Center for Soft Materials Xi'an Jiaotong University Xi'an 710049 China