1. Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, Virginia 24061, United States
2. Virginia Tech Institute of Critical Technology and Applied Science (ICTAS) Sustainable Nanotechnology Center (VTSuN), Blacksburg, Virginia 24061, United States
3. Center for the Environmental Implications of Nanotechnology (CEINT), Duke University, Durham, North Carolina 27708, United States
4. Department of Electrical and Computer Engineering, Virginia Tech, Blacksburg, Virginia 24060, United States