1. Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL 60637, USA.
2. Sciences of Extreme Materials Division, Polymers Branch, US DEVCOM Army Research Laboratory, Aberdeen Proving Ground, MD 21005, USA.
3. Materials Science and Engineering Division, National Institutes of Standards and Technology (NIST), Gaithersburg, MD 20899, USA.
4. NASA Glenn Research Center, Cleveland, OH 44135, USA.
5. Center for Molecular Engineering, Argonne National Laboratory, Lemont, IL 60439, USA.
6. Department of Chemistry, University of Chicago, Chicago, IL 60637, USA.