1. Department of Chemistry, Rice University, Houston, Texas 77005, United States
2. Shared Equipment Authority, Rice University, Houston, Texas 77005, United States
3. Smalley-Curl Institute, Rice University, Houston, Texas 77005, United States
4. Department of Materials Science and NanoEngineering, Rice University, Houston, Texas 77005, United States
5. NanoCarbon Center and the Welch Institute for Advanced Materials, Rice University, Houston, Texas 77005, United States