Thermal conductivity and Raman spectra of carbon fibers

Heremans, Joseph P.; Rahim, Ishrat; Dresselhaus, M. S.

doi:10.1103/physrevb.32.6742

Cited by 108 publications

(41 citation statements)

References 12 publications

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“…The key improvements over earlier fibers are due to the combined effect of CNT length, type, and graphitic character, as also observed recently in CNT films (28). Thermal conductivity appears to follow electrical conductivity [as in conventional carbon fibers (29)]; it is~30 times as high as that of wet-spun 0. Figure 2, B and C, compare CNT fibers (from this article and from the literature) to the materials with the best mechanical, electrical, and thermal properties.…”

mentioning

confidence: 63%

Strong, Light, Multifunctional Fibers of Carbon Nanotubes with Ultrahigh Conductivity

Behabtu

Young

Tsentalovich

et al. 2013

Science

1,185

1,075

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Broader applications of carbon nanotubes to real-world problems have largely gone unfulfilled because of difficult material synthesis and laborious processing. We report high-performance multifunctional carbon nanotube (CNT) fibers that combine the specific strength, stiffness, and thermal conductivity of carbon fibers with the specific electrical conductivity of metals. These fibers consist of bulk-grown CNTs and are produced by high-throughput wet spinning, the same process used to produce high-performance industrial fibers. These scalable CNT fibers are positioned for high-value applications, such as aerospace electronics and field emission, and can evolve into engineered materials with broad long-term impact, from consumer electronics to long-range power transmission.O n the molecular level, carbon nanotubes (CNTs) have an outstanding combination of mechanical strength and stiffness, electrical and thermal conductivity, and low density, making them ideal multifunctional materials that combine the best properties of polymers, carbon fibers, and metals (1). However, such outstanding properties have remained elusive on a macroscopic scale. Handling CNTs with sufficient length, stiffness, and chemical inertness introduces major challenges in material processing. Here we report lightweight fibers that approach the high specific strength of polymeric and carbon fibers, while also achieving the high specific electrical conductivity of metals and the specific thermal conductivity of graphite fibers.Two distinct routes have been developed for manufacturing neat CNT fibers (2). One route employs a solid-state process wherein CNTs are either directly spun into a fiber from the synthesis reaction zone (3, 4) or from a CNT forest grown on a solid substrate (5). This approach does not lend itself to the typical easy scale-up of chemical processes, as it combines multiple steps into a single one, limiting the options for process and material optimization. Indeed, solidstate fibers have low packing and poor orientation, and include impurities within their structure (6). Despite these shortcomings, solid-state CNT fibers have delivered the best properties so far (3, 4, 7-9). The reason for this relative success is the length of the CNTs that constitute these fibers-1 mm or more (2). Longer CNTs reduce the number of CNT ends in a fiber, yielding greater strength (10) and reducing CNT junctions, which increases electrical and thermal conductivity (11). The alternate fiber production route-wet spinning-was the first method for producing CNT fibers (12). In this process, premade CNTs are dissolved or dispersed in a fluid, extruded out of a spinneret, and coagulated into a solid fiber by extracting the dispersant. Wet spinning is easily scaled to industrial levels and is indeed the route by which highperformance fibers are manufactured (including ballistic fibers such as Kevlar and Twaron and structural fibers such as Toho Tenax and Thornel carbon fibers) (13). Decoupling the synthesis of CNTs from the spinning of the fibers allo...

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mentioning

confidence: 63%

Strong, Light, Multifunctional Fibers of Carbon Nanotubes with Ultrahigh Conductivity

Behabtu

Young

Tsentalovich

et al. 2013

Science

1,185

1,075

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“…Several techniques have been developed to measure the thermal conductivity and thermal diffusivity of carbon fiber [2,[4][5][6][7][8][9][10][11][12]. For the thermal-conductivity measurement, Raman spectroscopy is a powerful technique, which is also applied to characterize the crystalline perfections [4].…”

Section: Introductionmentioning

confidence: 99%

Simultaneous Measurements of Thermal Properties of Individual Carbon Fibers

et al. 2011

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Combining the steady-state and quasi-steady-state T type probes, the longitudinal thermal conductivity and thermal effusivity of individual mesophase pitchbased carbon fiber heat treated at 2800 • C and 1000 • C have been measured from 100 K to 300 K. The present method allows simultaneous measurements of thermal properties using the same instrument, by simply changing the applied direct current to alternating current. The specific heat is found to decrease with increasing heattreatment temperature and to approach the value of graphite. The highly graphitized carbon fiber has a maximum thermal conductivity of 410 W · m −1 · K −1 at about 250 K, and its thermal diffusivity decreases with increasing temperature. Comparatively, the thermal conductivity of the fiber heat treated at 1000 • C is much smaller, with the peak shifting to high temperature due to a large defect density, and its thermal diffusivity is nearly temperature independent.

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“…The position, width and relative intensities of bands G and D have been used successfully to study the structural changes involved in different carbonaceous materials subjected to different treatments, such as graphitisation processes (Bustin et al 1995), graphite implantation (Elman et al 1981), the production of carbon fibres (Heremans et al 1985;Chieu et al 1982), laser ablation (Lippert et al 1999) or the production of single-wall nanotubes (Dresselhaus et al 2002) .…”

Section: Raman Spectroscopy Studymentioning

confidence: 99%

Structural Changes in Polyethylene Terephthalate (PET) Waste Materials Caused by Pyrolysis and CO₂Activation

Parra

Ania

Arenillas

et al. 2006

Adsorption Science & Technology

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For ecological reasons, there is an increasing demand for recycling polyethylene terephthalate (PET) wastes in developed countries. Although one potential application might be its utilisation for the production of activated carbons, the behaviour of these wastes when subjected to different heat treatments and activation processes is still not very well known.In the present work, samples with different degrees of burn-off were prepared by pyrolysis in an inert atmosphere and subsequent CO 2 activation at high temperatures. The derived changes in the textural and structural properties of the residual solids were studied by helium picnometry, N 2 and CO 2 adsorption isotherms, powder XRD, Raman spectroscopy and XPS. The study reveals that CO 2 activation of PET wastes develops a carbonaceous matrix with micropores. Helium measurements showed that the mass density of the activated samples increased as the degree of burn-off increased. Characterisation studies revealed that the structural changes derived from pyrolysis and further CO 2 activation mostly involved a progressive decrease in the number of structural units.

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Thermal conductivity and Raman spectra of carbon fibers

Cited by 108 publications

References 12 publications

Strong, Light, Multifunctional Fibers of Carbon Nanotubes with Ultrahigh Conductivity

Strong, Light, Multifunctional Fibers of Carbon Nanotubes with Ultrahigh Conductivity

Simultaneous Measurements of Thermal Properties of Individual Carbon Fibers

Structural Changes in Polyethylene Terephthalate (PET) Waste Materials Caused by Pyrolysis and CO₂Activation

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Thermal conductivity and Raman spectra of carbon fibers

Cited by 108 publications

References 12 publications

Strong, Light, Multifunctional Fibers of Carbon Nanotubes with Ultrahigh Conductivity

Strong, Light, Multifunctional Fibers of Carbon Nanotubes with Ultrahigh Conductivity

Simultaneous Measurements of Thermal Properties of Individual Carbon Fibers

Structural Changes in Polyethylene Terephthalate (PET) Waste Materials Caused by Pyrolysis and CO2Activation

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Structural Changes in Polyethylene Terephthalate (PET) Waste Materials Caused by Pyrolysis and CO₂Activation