1. Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
2. Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
3. Exxon Mobil Research and Engineering Company, Clinton, New Jersey 08809, United States
4. Exxon Mobil Chemical Company, Baytown, Texas 77520, United States