Showing papers by "Rodney S. Ruoff published in 2000"
TL;DR: The tensile strengths of individual multiwalled carbon nanotubes (MWCNTs) were measured with a "nanostressing stage" located within a scanning electron microscope and a variety of structures were revealed, such as a nanotube ribbon, a wave pattern, and partial radial collapse.
Abstract: The tensile strengths of individual multiwalled carbon nanotubes (MWCNTs) were measured with a “nanostressing stage” located within a scanning electron microscope. The tensile-loading experiment was prepared and observed entirely within the microscope and was recorded on video. The MWCNTs broke in the outermost layer (“sword-in-sheath” failure), and the tensile strength of this layer ranged from 11 to 63 gigapascals for the set of 19 MWCNTs that were loaded. Analysis of the stress-strain curves for individual MWCNTs indicated that the Young's modulus E of the outermost layer varied from 270 to 950 gigapascals. Transmission electron microscopic examination of the broken nanotube fragments revealed a variety of structures, such as a nanotube ribbon, a wave pattern, and partial radial collapse.
5,011 citations
TL;DR: The mechanical response of 15 single wall carbon nanotube (SWCNT) ropes under tensile load was measured and strain data were obtained and they broke at strain values of 5.3% or lower.
Abstract: The mechanical response of 15 single wall carbon nanotube (SWCNT) ropes under tensile load was measured. For 8 of these ropes strain data were obtained and they broke at strain values of $5.3%$ or lower. The force-strain data are well fit by a model that assumes the load is carried by the SWCNTs on the perimeter of each rope. This model provides an average breaking strength of SWCNTs on the perimeter of each rope; the 15 values range from 13 to 52 GPa (mean 30 GPa). Based on the same model the 8 average Young's modulus values determined range from 320 to 1470 GPa (mean 1002 GPa).
2,594 citations
TL;DR: In this article, a systematic study has been performed in order to find an appropriate medium for solubilization/dispersion of pristine single-walled carbon nanotubes (SWCNTs).
Abstract: A systematic study has been performed in order to find an appropriate medium for solubilization/dispersion of pristine single-walled carbon nanotubes (SWCNTs). Five solvents, all featuring high electron pair donicity (β) and low hydrogen bond parameter (α) have demonstrated the ability to readily form stable dispersions. The best dispersions have been characterized by UV/visible-NIR spectra, ESR spectra, and atomic force microscopy (AFM).
666 citations
TL;DR: In this article, a mechanical loading stage operating inside a scanning electron microscopy (SEM) was used to realize the sliding between nested shells of multiwalled carbon nanotubes (MWCNTs).
Abstract: A mechanical-loading stage operating inside a scanning electron microscopy (SEM) was used to realize the sliding between nested shells of multiwalled carbon nanotubes (MWCNTs). A stick−slip motion and a smooth pullout motion were observed for the two separate MWCNTs studied. A model that includes the shear interaction, the “capillary” effect, and the edge effect, was used to explain the observed sliding between nested shells. The shear strength between shells was determined and the surface energy of the MWCNT shell estimated.
371 citations
TL;DR: In this paper, a root-growth mechanism is proposed for the catalyzed process of growing multiwalled BN nanotubes from nickel boride catalyst particles by chemical vapor deposition at 1000−1100 °C using borazine, B3N3H6, as the precursor.
Abstract: Multiwalled BN nanotubes are grown from nickel boride catalyst particles by chemical vapor deposition at 1000−1100 °C using borazine, B3N3H6, as the precursor. This precursor is generated in situ from molten salt that forms from mixtures of (NH4)2SO4, NaBH4, and Co3O4 at 300−400 °C. The BN nanotubes have concentric-tube structures, are free of internal closures, have crystalline walls, and exhibit lengths of up to ∼5 μm. The nanotubes often possess bulbous, flag-like, or club-like tip closures. A root-growth mechanism is proposed for the catalyzed process.
371 citations
Book•
01 Jan 2000
TL;DR: In this paper, Echegoyen et al. analyzed the properties of Fullerenes under high pressure and showed that Fullerene-based solvents exhibit properties similar to those of carbon-encapsulated metal nanoparticles.
Abstract: Electrochemistry of Fullerenes (L Echegoyen, et al) Solubility of the Fullerenes (M Korobov & A Smith) Organic Chemistry of Fullerenes (S Wilson, et al) Structural Inorganic Chemistry of Fullerenes and Fullerene--Like Compounds (A Balch) Photophysical Properties of Pristine Fullerenes, Functionalized Fullerenes, and Fullerene--Containing Donor--Bridge Acceptor Systems (D Guldi & P Kamat) Calculations of Higher Fullerenes and Quasi--Fullerenes (Z Slanina, et al) Polymer Derivatives of Fullerenes (L Chiang & L Wang) Endohedral Metallofullerenes: Production, Separation, and Structural Properties (H Shinohara) Endohedral Metallofullerenes: Theory, Electrochemistry, and Chemical Reactions (S Nagase, et al) Biological Aspects of Fullerenes (S Wilson) Carboxyfullerenes as Neuroprotective Antioxidants (L Dugan, et al) Fullerenes and Fullerene Ions in the Gas Phase (D Bohme, et al) Fullerene--Surface Interactions (A Hamza) Structures of Fullerene--Based Solids ( K Prassides & S Margadonna) Fullerenes Under High Pressure (B Sundqvist) Superconductivity in Fullerenes (V Buntar) Boron Nitride--Containing Nanotubes (N Chopra & A Zettl) Synthesis and Characterization of Materials Incorporated within Carbon Nanotubes (J Sloan & M Green) Synthesis, Structure, and Properties of Carbon Encapsulated Metal Nanoparticles (M McHenry & S Subramoney) Molecular and Solid C 36 (J Grossman, et al) Index
301 citations
TL;DR: Tapping-mode atomic force microscopy was used to study the radial deformability of a multiwalled carbon nanotube (MWCNT) and demonstrate its remarkable reversible radial deformable and reveal internal discontinuities along its length.
Abstract: Tapping-mode atomic force microscopy was used to study the radial deformability of a multiwalled carbon nanotube (MWCNT). By imaging the MWCNT under different tapping forces, we were able to demonstrate its remarkable reversible radial deformability (up to $\ensuremath{\sim}40%$) and reveal internal discontinuities along its length. The values of the effective elastic modulus of several sections of the MWCNT in the radial direction were estimated with the Hertz model.
199 citations
TL;DR: In this article, the use of a bilayer resist to facilitate the metal lifto-ff step in imprinter fabrication is presented. But the technique has a resolution of better than 10 nm and exhibits more uniform patterns and fewer missing features than similar metal nanoparticle arrays fabricated with single layer resist.
Abstract: Nanoimprint lithography has been shown to be a viable means of patterning polymer films in the sub-100 nm range. In this work, we demonstrate the use of a bilayer resist to facilitate the metal liftoff step in imprinter fabrication. The bilayer resist technology exhibits more uniform patterns and fewer missing features than similar metal nanoparticle arrays fabricated with single layer resist. The bilayer resist relies upon the differential solubility between poly(methyl methacrylate) and poly(methyl methacrylate methacrylic acid copolymer). Evidence is presented that shows the technique has a resolution of better than 10 nm.
45 citations
TL;DR: In this paper, a root-growth mechanism is proposed for the catalyzed process of growing multiwalled BN nanotubes from nickel boride catalyst particles by chemical vapor deposition at 1000−1100 °C using borazine, B3N3H6, as the precursor.
Abstract: Multiwalled BN nanotubes are grown from nickel boride catalyst particles by chemical vapor deposition at 1000−1100 °C using borazine, B3N3H6, as the precursor. This precursor is generated in situ from molten salt that forms from mixtures of (NH4)2SO4, NaBH4, and Co3O4 at 300−400 °C. The BN nanotubes have concentric-tube structures, are free of internal closures, have crystalline walls, and exhibit lengths of up to ∼5 μm. The nanotubes often possess bulbous, flag-like, or club-like tip closures. A root-growth mechanism is proposed for the catalyzed process.
1 citations