Carbon nanotubes in an ancient Damascus sabre

Reibold, M.; Paufler, P.; Levin, A. A.; Kochmann, W.; Pätzke, N.; Meyer, Dirk C.

doi:10.1038/444286a

Cited by 241 publications

(105 citation statements)

References 11 publications

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“…In agreement with literature values, the typical fluorescence QY was ~0.04% for micelleencapsulated SWNTs. 71,150 Interestingly, the purified sample of DNA-wrapped (6,5) semiconducting SWNTs displayed a QY that was nearly three times greater than that of the heterogeneous, surfactant-wrapped samples. 151 …”

Section: Ensemble Fluorescence Quantum Yieldsmentioning

confidence: 97%

“…For example, transmission electron microscopy (TEM) recently revealed the presence of MWNTs in the ultrahigh-carbon steel of a seventeenth century Damascus sabre, similar to those originally produced for the Crusades. 5 The presence of carbon nanotubes in the blade gave these Middle Eastern swords unique properties, including exceptional strength, not typical of European steels, and an unusually sharp cutting edge.…”

Section: Discovery Of Carbon Nanotubesmentioning

confidence: 99%

“…87 b Fluorescence intensities were later corrected by the excitation intensity and detection efficiency at the peak emission wavelength. c The absorption cross section was measured for enriched (6,5) SWNTs and was used to estimate approximate values for all other chiralities in this study.…”

Section: Fluorescence Intensities Of Single Moleculesmentioning

confidence: 99%

“…To quantify the fraction of absorbance that was contributed only by SWNTs, we performed photoluminescence excitation spectroscopy, in which a library of fluorescence spectra are acquired as a tunable source changes the excitation wavelength; PLE and absorption spectroscopy provide similar information, but only species that emit can contribute to the PLE intensity. Therefore, when detecting fluorescence from only the (6,5) SWNT (at ~990 nm), the relative ratio of the PLE intensities at E 22 and 633 nm serves to quantify the fraction of the sample that absorbs at 633 nm and also contributes to (6,5) nanotube fluorescence (assuming the absorption at E 22 is all from (6,5) SWNTs). From the absorption spectrum, E 22 :633 nm is ~2.5 and from the PLE spectrum, E 22 :633 nm is ~4.9.…”

Section: Absorption Cross Section Of Swntsmentioning

confidence: 99%

“…Interestingly, it is possible that fluorescence from these weak emitters was quenched upon initial exposure to the photoexcitation, that their fluorescence intensity was too low to be detected with the laser power and integration time used here, or that these were (7,5) SWNTs that emitted too far to the red to be detected efficiently with the CCD.…”

Section: Correlated Fluorescence and Topographymentioning

confidence: 99%

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Photophysics of Individual Single-Walled Carbon Nanotubes

2008

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Single-walled carbon nanotubes (SWNTs) are cylindrical graphitic molecules that have remained at the forefront of nanomaterials research since 1991, largely due to their exceptional and unusual mechanical, electrical, and optical properties. The motivation for understanding how nanotubes interact with light (i.e., SWNT photophysics) is both fundamental and applied. Individual nanotubes may someday be used as superior near-infrared fluorophores, biological tags and sensors, and components for ultrahigh-speed optical communications systems. Establishing an understanding of basic nanotube photophysics is intrinsically significant and should enable the rapid development of such innovations. Unlike conventional molecules, carbon nanotubes are synthesized as heterogeneous samples, composed of molecules with different diameters, chiralities, and lengths. Because a nanotube can be either metallic or semiconducting depending on its particular molecular structure, SWNT samples are also mixtures of conductors and semiconductors. Early progress in understanding the optical characteristics of SWNTs was limited because nanotubes aggregate when synthesized, causing a mixing of the energy states of different nanotube structures. Recently, significant improvements in sample preparation have made it possible to isolate individual nanotubes, enabling many advances in characterizing their optical properties. In this Account, single-molecule confocal microscopy and spectroscopy were implemented to study the fluorescence from individual nanotubes. Single-molecule measurements naturally circumvent the difficulties associated with SWNT sample inhomogeneities. Intrinsic SWNT photoluminescence has a simple narrow Lorentzian line shape and a polarization dependence, as expected for a one-dimensional system. Although the local environment heavily influences the optical transition wavelength and intensity, single nanotubes are exceptionally photostable. In fact, they have the unique characteristic that their single molecule fluorescence intensity remains constant over time; SWNTs do not “blink” or photobleach under ambient conditions. In addition, transient absorption spectroscopy was used to examine the relaxation dynamics of photoexcited nanotubes and to elucidate the nature of the SWNT excited state. For metallic SWNTs, very fast initial recovery times (300–500 fs) corresponded to excited-state relaxation. For semiconducting SWNTs, an additional slower decay component was observed (50–100 ps) that corresponded to electron–hole recombination. As the excitation intensity was increased, multiple electron–hole pairs were generated in the SWNT; however, these e−h pairs annihilated each other completely in under 3 ps. Studying the dynamics of this annihilation process revealed the lifetimes for one, two, and three e−h pairs, which further confirmed that the photoexcitation of SWNTs produces not free electrons but rather one-dimensional bound electron–hole pairs (i.e., excitons). In summary, nanotube photophysics is a rapidly developing area o...

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Section: Ensemble Fluorescence Quantum Yieldsmentioning

confidence: 97%

Section: Discovery Of Carbon Nanotubesmentioning

confidence: 99%

Section: Fluorescence Intensities Of Single Moleculesmentioning

confidence: 99%

Section: Absorption Cross Section Of Swntsmentioning

confidence: 99%

Section: Correlated Fluorescence and Topographymentioning

confidence: 99%

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Photophysics of Individual Single-Walled Carbon Nanotubes

2008

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Introduction to Nanocatalysis

Polshettiwar¹,

Asefa²

2013

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Nanoarchaeology

Pérez-Arantegui

2018

The Encyclopedia of Archaeological Sciences

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Nanomaterials (materials containing particles with one or more dimensions in the size range 1–100 nm) were already present in ancient objects, with similar features to currently engineered nanostructures, justifying the so‐called nanoarchaeology of these items. Most of these nanomaterials were included in colored glass and ceramic glazes, with metallic nanoparticles of gold, copper, or silver, but also some pigments were nanostructured, like Maya blue, or some properties of ancient metal alloys were due to the precipitation of crystalline nanophases or nanotubes. Hence, even if materials with nanometric sizes were inadvertently produced during ancient times, their remarkable properties were already well clear.

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Carbon nanotubes in an ancient Damascus sabre

Cited by 241 publications

References 11 publications

Photophysics of Individual Single-Walled Carbon Nanotubes

Photophysics of Individual Single-Walled Carbon Nanotubes

Introduction to Nanocatalysis

Nanoarchaeology

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