1. Department of Mechanical Engineering, Imperial College London, London SW7 2AZ, U.K.
2. Department of Materials, Imperial College London, London SW7 2AZ, U.K.
3. Department of Materials, ETH Zürich, Zürich 8092, Switzerland
4. Department of Mechanical Engineering, University of California, Merced, Merced, California 95343, United States
5. Afton Chemical Corporation, Richmond, Virginia 23219, United States