1. Physicochemical characterization, and relaxometry studies of micro-graphite oxide, graphene nanoplatelets, and nanoribbons
- Author
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Balaji Sitharaman, Shruti Kanakia, Leonard Deepak Francis, Bhavna S. Paratala, and Barry D. Jacobson
- Subjects
Chemical Phenomena ,Magnetic Properties ,Intercalation (chemistry) ,Nanoparticle ,Contrast Media ,lcsh:Medicine ,02 engineering and technology ,Microscopy, Atomic Force ,Spectrum Analysis, Raman ,01 natural sciences ,Nanomaterials ,law.invention ,Diagnostic Radiology ,chemistry.chemical_compound ,law ,Materials Chemistry ,Nanotechnology ,lcsh:Science ,Microstructure ,Mathematical Computing ,Multidisciplinary ,Chemistry ,Oxides ,021001 nanoscience & nanotechnology ,Magnetic Resonance Imaging ,Medicine ,Materials Characterization ,Graphite ,Material by Structure ,0210 nano-technology ,Radiology ,Graphene nanoribbons ,Research Article ,Intermetallics ,Materials Science ,Material Properties ,Graphite oxide ,Carbon nanotube ,010402 general chemistry ,Magnetic Materials ,Material by Attribute ,Microscopy, Electron, Transmission ,Graphene oxide paper ,Graphene ,Nanotubes, Carbon ,lcsh:R ,0104 chemical sciences ,Chemical engineering ,Bionanotechnology ,Microscopy, Electron, Scanning ,Nanoparticles ,lcsh:Q ,Mathematics - Abstract
The chemistry of high-performance magnetic resonance imaging contrast agents remains an active area of research. In this work, we demonstrate that the potassium permanganate-based oxidative chemical procedures used to synthesize graphite oxide or graphene nanoparticles leads to the confinement (intercalation) of trace amounts of Mn(2+) ions between the graphene sheets, and that these manganese intercalated graphitic and graphene structures show disparate structural, chemical and magnetic properties, and high relaxivity (up to 2 order) and distinctly different nuclear magnetic resonance dispersion profiles compared to paramagnetic chelate compounds. The results taken together with other published reports on confinement of paramagnetic metal ions within single-walled carbon nanotubes (a rolled up graphene sheet) show that confinement (encapsulation or intercalation) of paramagnetic metal ions within graphene sheets, and not the size, shape or architecture of the graphitic carbon particles is the key determinant for increasing relaxivity, and thus, identifies nano confinement of paramagnetic ions as novel general strategy to develop paramagnetic metal-ion graphitic-carbon complexes as high relaxivity MRI contrast agents.
- Published
- 2012