1. Department of Chemistry Faculty of Science National University of Singapore 3 Science Drive 3 Singapore 117543 Singapore
2. Max Planck Institute for Polymer Research Ackermannweg 10 55128 Mainz Germany
3. School of Science and Technology Nottingham Trent University Clifton Lane Nottingham NG11 8NS UK
4. Joint School of National University of Singapore and Tianjin University International Campus of Tianjin University Binhai New City, Fuzhou 350207 China