Pasha Nikolaev

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We describe, in detail, a readily scalable purification process capable of handling single-wall carbon nanotube (SWNT) material in large batches. Characterization of the resulting material by SEM, TEM, XRD, Raman scattering, and TGA shows it to be highly pure. Resistivity measurements on freestanding mats of the purified tubes are also reported. We also(More)
(nominal inner diameter: 0.6 mm) needles into rotating 40 wt.-% PEI (branched; average molecular weight, M w ~ 25 000; water-free; Aldrich) solutions in methanol. The SWNT/PEI composite fibers were characterized by SEM (LEO 1590 VP microscope) and micro-Raman spectroscopy (Jobin± Yvon Horiba high-resolution LabRam micro-Raman spectrometer; helium±neon(More)
Field emission of electrons from individually mounted carbon nanotubes has been found to be dramatically enhanced when the nanotube tips are opened by laser evaporation or oxidative etching. Emission currents of 0.1 to 1 microampere were readily obtained at room temperature with bias voltages of less than 80 volts. The emitting structures are concluded to(More)
ZnS, an important wide-bandgap semiconductor, is a photo-luminescence material. [1] Due to its wide bandgap of 3.8 eV, doping of ZnS with elements such as Tb and Eu, [2] can produce a wide range of exciting optical properties. Quantum dots of core±shell structured CdSe/ZnS have been found to exhibit a lasing effect and can be used for fluoro-immunoas-says,(More)
Carbon nanotubes produced in arcs have been found to have the form of multiwalled fullerenes, at least over short lengths. Sintering of the tubes to each other is the predominant source of defects that limit the utility of these otherwise perfect fullerene structures. The use of a water-cooled copper cathode minimized such defects, permitting nanotubes(More)
We have measured temperature (T)-and power-dependent electron spin resonance in bulk single-wall carbon nanotubes to determine both the spin-lattice and the spin-spin relaxation times, T 1 and T 2. We observe that T −1 1 increases linearly with T from 4 K to 100 K, whereas T −1 2 decreases by over a factor of two when T is increased from 3 K to 300 K. We(More)
PURPOSE The NASA-NIST Workshop Series devoted to Single Wall Carbon Nanotubes is to focus the community's attention on the issues of nanotube quality and characterization. Leading experts convene to discuss forefront efforts in the areas of dispersion, purity, and characterization. The output of the second meeting was a Recommended Practice Guide, which(More)
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