Multiwalled carbon nanotubes and dispersed nanodiamond novel hybrids: Microscopic structure evolution, physical properties, and radiation resilience
- Department of Chemistry and Biophysics Program, University of Pennsylvania, 3301 Spruce Street, Philadelphia, Pennsylvania 19104 (United States)
- Department of Physics, Missouri University Research Reactor, University of Missouri-Columbia, Missouri 65211 (United States)
We report the structure and physical properties of novel hybrids of multiwalled carbon nanotubes (MWCNTs) and ultradispersed diamond (UDD) forming nanocomposite ensemble that were subjected to 50, 100, and 10{sup 3} kGy gamma ray doses and characterized using various analytical tools to investigate hierarchical defects evolution. This work is prompted by recent work on single-walled CNTs and UDD ensemble [Gupta et al., J. Appl. Phys. 107, 104308 (2010)] where radiation-induced microscopic defects seem to be stabilized by UDD. The present experiments show similar effects where these hybrids display only a minimal structural modification under the maximum dose. Quantitative analyses of multiwavelength Raman spectra revealed lattice defects induced by irradiation assessed through the variation in prominent D, G, and 2D bands. A minimal change in the position of D, G, and 2D bands and a marginal increase in intensity of the defect-induced double resonant Raman scattered D and 2D bands are some of the implications suggesting the radiation coupling. The in-plane correlation length (L{sub a}) was also determined following Tunistra-Koenig relation from the ratio of D to G band (I{sub D}/I{sub G}) besides microscopic stress. However, we also suggest the following taking into account of intrinsic defects of the constituents: (a) charge transfer arising at the interface due to the difference in electronegativity of MWCNT C sp{sup 2} and UDD core (C sp{sup 3}) leading to phonon and electron energy renormalization; (b) misorientation of C sp{sup 2} at the interface of MWCNT and UDD shell (C sp{sup 2}) resulting in structural disorder; (c) softening or violation of the q{approx}0 selection rule leading to D band broadening and a minimal change in G band intensity; and (d) normalized intensity of D and G bands with 2D band help to distinguish defect-induced double resonance phenomena. The MWCNT when combined with nanodiamond showed a slight decrease in their conductance further affected by irradiation pointing at relatively good interfacial contact. Furthermore, owing to high thermal and electrical conductivity properties, they can facilitate potentially efficient heat-transfer applications and some results deduced using Nielsen's model is provided.
- OSTI ID:
- 21538033
- Journal Information:
- Journal of Applied Physics, Vol. 109, Issue 1; Other Information: DOI: 10.1063/1.3524187; (c) 2011 American Institute of Physics; ISSN 0021-8979
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
CARBON
CHARGE EXCHANGE
COMPOSITE MATERIALS
CORRELATIONS
COUPLING
CRYSTAL DEFECTS
DIAMONDS
ELECTRIC CONDUCTIVITY
ELECTRONEGATIVITY
GAMMA RADIATION
HEAT TRANSFER
IRRADIATION
NANOTUBES
PHONONS
RAMAN SPECTRA
RENORMALIZATION
RESONANCE
SELECTION RULES
SURFACES
THERMAL CONDUCTIVITY
CRYSTAL STRUCTURE
ELECTRICAL PROPERTIES
ELECTROMAGNETIC RADIATION
ELEMENTS
ENERGY TRANSFER
IONIZING RADIATIONS
MATERIALS
MINERALS
NANOSTRUCTURES
NONMETALS
PHYSICAL PROPERTIES
QUASI PARTICLES
RADIATIONS
SPECTRA
THERMODYNAMIC PROPERTIES