1. Physical Sciences and Engineering Division; King Abdullah University of Science and Technology (KAUST); Thuwal 23955-6900 Saudi Arabia
2. Interdisciplinary Nanoscience Center (iNANO) and Department of Chemistry; Aarhus University; Gustav Wieds Vej 14 DK-8000 Aarhus C Denmark
3. Max Planck Institute for Polymer Research; Ackermannweg 10 D-55128 Mainz Germany
4. Stanford Synchrotron Radiation Laboratory (SSRL); Menlo Park CA 94025 USA