Journal ArticleDOI
Band gap fluorescence from individual single-walled carbon nanotubes.
Michael J. O'Connell,Sergei M. Bachilo,Chad B. Huffman,Valerie C. Moore,Michael S. Strano,Erik H. Haroz,Kristy L. Rialon,Peter J. Boul,William H. Noon,Carter Kittrell,Jianpeng Ma,Jianpeng Ma,Robert H. Hauge,R. Bruce Weisman,Richard E. Smalley +14 more
TLDR
At pH less than 5, the absorption and emission spectra of individual nanotubes show evidence of band gap–selective protonation of the side walls of the tube, which is readily reversed by treatment with base or ultraviolet light.Abstract:
Fluorescence has been observed directly across the band gap of semiconducting carbon nanotubes. We obtained individual nanotubes, each encased in a cylindrical micelle, by ultrasonically agitating an aqueous dispersion of raw single-walled carbon nanotubes in sodium dodecyl sulfate and then centrifuging to remove tube bundles, ropes, and residual catalyst. Aggregation of nanotubes into bundles otherwise quenches the fluorescence through interactions with metallic tubes and substantially broadens the absorption spectra. At pH less than 5, the absorption and emission spectra of individual nanotubes show evidence of band gap-selective protonation of the side walls of the tube. This protonation is readily reversed by treatment with base or ultraviolet light.read more
Citations
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Cytotoxicity effects of different surfactant molecules conjugated to carbon nanotubes on human astrocytoma cells.
TL;DR: Observations suggest that the single-walled carbon nanotube (SWCNTs) could be used as non-viral vectors for diagnostic and therapeutic molecules across the blood–brain barrier to the brain and the central nervous system.
Journal ArticleDOI
Disaggregation of single-walled carbon nanotubes (SWNTs) promoted by the ionic liquid-based surfactant 1-hexadecyl-3-vinyl-imidazolium bromide in aqueous solution
Antonello Di Crescenzo,Davide Demurtas,Andrea Renzetti,Gabriella Siani,Paolo De Maria,Moreno Meneghetti,Maurizio Prato,Antonella Fontana +7 more
TL;DR: In this paper, stable homogeneous aqueous dispersions of pristine single-walled carbon nanotubes (SWNTs) are obtained by using a water-soluble long-chain imidazolium ionic liquid (hvimBr) above its critical micelle concentration.
Journal ArticleDOI
Single Gold-Nanoparticle-Enhanced Raman Scattering of Individual Single-Walled Carbon Nanotubes via Atomic Force Microscope Manipulation
TL;DR: In this article, a single gold-nanoparticle-enhanced Raman scattering of individual single-walled carbon nanotubes (SWNTs) by atomic force microscope (AFM) manipulation is reported.
Journal ArticleDOI
Carbon nanotube network formation from evaporating sessile drops.
TL;DR: Fabrication of single-walled carbon nanotube (SWNT) networks using evaporation of SDS-SWNT sessile drops on a hydrophobized silicon substrate is reported and it is suggested that the organization of nanotubes during Evaporation is controlled by aggregates (in the SDS -SWNT dispersion) and hydrophobia of the substrate.
Journal ArticleDOI
Engineered Nanoparticles and Their Identification Among Natural Nanoparticles
TL;DR: This work discusses the most important methods of fractionation and detection of both natural and engineered nanoparticles, with a focus on the chemical nature of the particles, particle concentration, and particle size.
References
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CHARMM: A program for macromolecular energy, minimization, and dynamics calculations
Bernard R. Brooks,Robert E. Bruccoleri,Barry D. Olafson,David J. States,S. Swaminathan,Martin Karplus +5 more
TL;DR: The CHARMM (Chemistry at Harvard Macromolecular Mechanics) as discussed by the authors is a computer program that uses empirical energy functions to model macromolescular systems, and it can read or model build structures, energy minimize them by first- or second-derivative techniques, perform a normal mode or molecular dynamics simulation, and analyze the structural, equilibrium, and dynamic properties determined in these calculations.
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MOLSCRIPT: a program to produce both detailed and schematic plots of protein structures
TL;DR: The MOLSCRIPT program as discussed by the authors produces plots of protein structures using several different kinds of representations, including simple wire models, ball-and-stick models, CPK models and text labels.
Journal ArticleDOI
Crystalline Ropes of Metallic Carbon Nanotubes
Andreas Thess,R. S. Lee,Pavel Nikolaev,Hongjie Dai,Pierre Petit,J. Robert,Chunhui Xu,Young Hee Lee,Seong-Gon Kim,Andrew G. Rinzler,Daniel T. Colbert,Gustavo E. Scuseria,David Tománek,John E. Fischer,Richard E. Smalley +14 more
TL;DR: X-ray diffraction and electron microscopy showed that fullerene single-wall nanotubes (SWNTs) are nearly uniform in diameter and that they self-organize into “ropes,” which consist of 100 to 500 SWNTs in a two-dimensional triangular lattice with a lattice constant of 17 angstroms.
Book
Science of fullerenes and carbon nanotubes
TL;DR: In this paper, the authors present a detailed overview of the properties of Fullerenes and their properties in surface science applications, such as scanning tunnel microscopy, growth and fragmentation studies, and chemical synthesis.
Journal ArticleDOI
Constant pressure molecular dynamics simulation: The Langevin piston method
TL;DR: In this paper, a new method for performing molecular dynamics simulations under constant pressure is presented, which is based on the extended system formalism introduced by Andersen, the deterministic equations of motion for the piston degree of freedom are replaced by a Langevin equation; a suitable choice of collision frequency then eliminates the unphysical "ringing" of the volume associated with the piston mass.