| AVS 62nd International Symposium & Exhibition | |
| Nanometer-scale Science and Technology | Wednesday Sessions |
| Session NS-WeM |
| Session: | Nanodiamond for Optical and Biomedical Applications |
| Presenter: | Bryan Ringstrand, Los Alamos National Laboratory |
| Authors: | B. Ringstrand, Los Alamos National Laboratory R.C. Huber, Los Alamos National Laboratory D. Podlesak, Los Alamos National Laboratory D. Dattelbaum, Los Alamos National Laboratory R. Gustavsen, Los Alamos National Laboratory M. Firestone, Los Alamos National Laboratory |
| Correspondent: | Click to Email |
High explosive detonation is an exothermic process where CHNO molecules are transformed into, but not limited to, H2O, CO, CO2, N2, and solid carbon (i.e. soot). The type and quantity of carbon allotrope present depends on the explosive formulation and the temperature and pressure of the detonation. The carbon allotropes that form during a detonation include nanodiamond, graphite, and amorphous carbon; however, nanodiamonds are the most interesting. Due to their chemical inertness and biocompatibility, nanodiamonds have garnered interest in biomedical and electronic applications.1
The nature of a detonation event produces soot that is contaminated with metals, metal oxides, and other carbon phases (i.e. sp2 carbons). Removal of these species is essential to obtaining pristine nanodiamond. Metals and metal oxides are removed using mineral acid treatments; whereas, sp2 species are thermally oxidized above 400 oC.2 Although acid treatment and thermal oxidation generate pristine nanodiamond, these methods damage the characteristic markers that provide information about the processes and conditions that give rise to nanodiamond as a carbon allotrope.
Another benign approach could be surface functionalization of the soot followed by separation of functionalized and non-functionalized components. Carbon nanotubes have been known to de-aggregate and disperse in ionic liquids.3 A similar approach was demonstrated for pristine nanodiamond using an imidazolium based ionic liquid covalently bound to its surface. These functionalized nanodiamonds showed increased dispersibility in polar solvents and formed stable gels in other ionic liquids.4
Our efforts to adapt ionic liquids for the surface functionalization of nanocarbons produced by high explosive detonation will be discussed. Specifically, imidazolium based ionic liquids incorporating decyl chains through various coupling strategies will be reviewed. The functionalized nanocarbons could then be dispersed in solvents, allowing for individual component isolation and size fractionation. The isolated products were characterized using a range of techniques including SEM, TEM, powder X-ray diffraction, X-ray scattering, and XPS.
References:
1. Krueger, A.; Lang, D. Adv. Funct. Mater. 2012,22, 890.
2. Pichot, V.; Comet, M.; Fousoon, E.; Baras, C.; Senger, A.; Le Normand, F.; Spitzer, D. Diam. Relat. Mater. 2008,17, 13.
3. Fukushima, T.; Kosaka, A.; Ishimura, Y.; Yamamoto, T.; Takigawa, T.; Ishii, N.; Aida, T. Science 2003,300, 2072.
4. Park, C.; Young, A. Y.; Lee, M.; Lee, S. Chem. Commun. 2009, 5576.