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Journal ArticleDOI

Band gap fluorescence from individual single-walled carbon nanotubes.

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.

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Journal ArticleDOI

Helical wrapping of single-walled carbon nanotubes by water soluble poly(p-phenyleneethynylene).

TL;DR: Data reveal that the interaction of PPES with SWNTs gives rise to a self-assembled superstructure in which a polymer monolayer helically wraps the nanotube surface; the observed PPES pitch length confirms structural predictions made via molecular dynamics simulations.
Journal ArticleDOI

Single-walled carbon nanotubes dispersed in aqueous media via non-covalent functionalization: Effect of dispersant on the stability, cytotoxicity, and epigenetic toxicity of nanotube suspensions

TL;DR: A strong dependence of the toxicity of SWCNT suspensions on theoxicity of the dispersant is suggested and the potential of non-covalent functionalization with non-toxic dispersants as a method for the preparation of stable aqueous suspensions of biocompatible CNTs is pointed to.
Journal ArticleDOI

Noncovalent functionalization of single-walled carbon nanotubes with water-soluble porphyrins.

TL;DR: Porphyrin-coated SWNTs can be precisely aligned on hydrophilic poly(dimethylsiloxane) (PDMS) surfaces by combing SWNT solution along a desired direction and then transferred to silicon substrates by stamping.
Journal ArticleDOI

Dynamics of individual single-walled carbon nanotubes in water by real-time visualization.

TL;DR: It is determined that commonly available SWNTs in liquids can be considered as rigid Brownian rods in the absence of imposed external fields or self-attractive forces, in agreement with theoretical estimates.
Patent

Methods and applications of non-planar imaging arrays

TL;DR: In this article, a system, devices and methods are presented that provide an imaging array fabrication process, comprising fabricating an array of semiconductor imaging elements, interconnecting the elements with stretchable interconnections, and transfer printing the array with a pre-strained elastomeric stamp to a secondary non-planar surface.
References
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Journal ArticleDOI

CHARMM: A program for macromolecular energy, minimization, and dynamics calculations

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.
Journal ArticleDOI

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

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.
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