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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Microwave-assisted bromination of double-walled carbon nanotubes
Jf Colomer,Riccardo Marega,Hassan Traboulsi,Moreno Meneghetti,G. Van Tendeloo,Davide Bonifazi,Davide Bonifazi +6 more
TL;DR: In this paper, the first direct bromination of double-walled carbon nanotubes under microwave irradiation is reported, and XPS analysis demonstrates the formation of covalent C−Br bonds with a loading of ∼5% w/w.
Journal ArticleDOI
Triazenes as a Stable Diazonium Source for Use in Functionalizing Carbon Nanotubes in Aqueous Suspensions
TL;DR: In this paper, the synthesis of a biotin-containing triazene followed by reaction with single-wall carbon nanotubes (SWNTs) is described. But this method is particularly useful when a target molecule has functionality that will not tolerate diazotization conditions.
Journal ArticleDOI
Ionic Strength-Mediated Phase Transitions of Surface-Adsorbed DNA on Single-Walled Carbon Nanotubes
Daniel P. Salem,Xun Gong,Albert Tianxiang Liu,Volodymyr B. Koman,Juyao Dong,Michael S. Strano +5 more
TL;DR: A generic, ionic strength-mediated phase transition exhibited by over 25 distinct oligonucleotides adsorbed to single-walled carbon nanotubes (SWCNTs) in colloidal suspension is observed and it is shown that the phase transition also changes the observed SWCNT corona phase, modulating the recognition of riboflavin.
Journal ArticleDOI
Fundamental optical processes in armchair carbon nanotubes
Erik H. Haroz,Juan G. Duque,Xiaomin Tu,Ming Zheng,Angela R. Hight Walker,Robert H. Hauge,Stephen K. Doorn,Junichiro Kono +7 more
TL;DR: Post-synthesis separation methods based on density gradient ultracentrifugation and DNA-based ion-exchange chromatography are used to produce aqueous suspensions strongly enriched in armchair nanotubes, and resonant Raman spectroscopy of the radial breathing mode phonons are used, providing macroscopic and unambiguous evidence that density gradient Ultracentr ifugation can enrich ensemble samples in armchairs nanot tubes.
Journal ArticleDOI
Excitons in carbon nanotubes
Janina Maultzsch,R. Pomraenke,Stephanie Reich,E. Chang,Deborah Prezzi,Alice Ruini,Elisa Molinari,Michael S. Strano,Christian Thomsen,Christoph Lienau +9 more
TL;DR: The two-photon allowed exciton state, which has even parity under rotation about the U-axis, is roughly 300 meV above the onephoton active, odd-parity state as discussed by the authors.
References
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Journal ArticleDOI
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.