1. Department of Chemistry, Center for Optical Materials Science and Engineering Technology (COMSET), and Environmental Toxicology Program, Hunter Laboratories, Clemson University, Clemson, South Carolina 29634, United States
2. Electron Microscope Facility, Clemson University, Anderson, South Carolina 29625, United States
3. Department of Chemistry, Biosystems Research Complex (BRC), Clemson University, Clemson, South Carolina 29634, United States