1. Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, Singapore 117585
2. Institute of Materials Research and Engineering (IMRE), A*STAR (Agency for Science, Technology and Research), Innovis, 2 Fusionopolis Way, Singapore 138634
3. Department of Chemistry and Biochemistry, Northern Illinois University, DeKalb, Illinois 60115, United States
4. X-ray Science Division, Argonne National Laboratory, Lemont, Illinois 60439, United States