Thermal and electrical conductivity of tall, vertically aligned carbon nanotube arrays

Jakubinek, Michael B.; White, Mary Anne; Li, Ge; Jayasinghe, Chaminda; Cho, Wondong; Schulz, Mark J.; Shanov, Vesselin

doi:10.1016/j.carbon.2010.06.063

Cited by 130 publications

(75 citation statements)

References 23 publications

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“…values ( of the 1.5 μm long CNT array is much higher than that of the up to 6 mm high MWCNT array (with a thermal conductivity of (0.5 to 1.2) W · m −1 · K −1 at 300 K along the tube growth direction, with the shortest array having the highest value, and an order of magnitude lower in the direction perpendicular to the tubes.) [16]. However, tall MWCNT arrays are not ideal candidates for TIMs due to their size and correspondingly lower thermal conductance.…”

Section: Resultsmentioning

confidence: 99%

Experimental Reconstruction of Thermal Parameters in CNT Array Multilayer Structure

Wang

Tang

2011

Int J Thermophys

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The thermal conductivities, thermal diffusivity, thermal anisotropy ratio, and thermal boundary resistance for the multilayered microstructure of a carbon nanotube (CNT) array are reconstructed experimentally using the 3ω method with two different width metal heaters. The thermal impedance in the frequency domain and sensitivity coefficients are introduced to simultaneously determine the multiple thermal parameters. The thermal conductivity at 295 K is 38 W · m −1 · K −1 along the nanotube growth direction, and two orders of magnitude lower in the direction perpendicular to the tubes with the anisotropy ratio as large as 86. Separation of the contact and CNT array resistances is realized through circuit modeling. The measured thermal boundary resistances of the CNT array/Si substrate and insulating diamond film interfaces are 3.1 m 2 · K · MW −1 and 18.4 m 2 · K · MW −1 , respectively. The measured thermal boundary resistance between the heater and diamond film is 0.085 m 2 · K · MW −1 using a reference sample without a CNT array. The thermal conductivity for a CNT array already exceeds those of phase-changing thermal interface materials used in microelectronics.

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Section: Resultsmentioning

confidence: 99%

Experimental Reconstruction of Thermal Parameters in CNT Array Multilayer Structure

Wang

Tang

2011

Int J Thermophys

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“…In this case, the nanotubes are forced to proceed vertically due to the steric hindrance from adjacent nanotubes. It was reported recently that iron catalyst particles stabilized in an alumina matrix result in millimeter-long, vertically aligned, brush-like CNTs at a temperature of 750 8C or more, [26,35,36] however, in the case of Al foil, CNTs should be synthesized necessarily at a temperature lower than 660 8C to prevent melting of the substrate. Such a temperature, which is quite low for efficient CCVD, leads to a decelerating performance of most , and b) the mean value and standard deviation of capacitance of corresponding electrodes calculated using data presented in Figure 5a.…”

Section: Cnts Grown On Al Foils As Edlc Electrodes: Problems and Solumentioning

confidence: 99%

“…[28,29] Aluminum oxide is commonly used as a support preventing the catalyst particles (usually Fe, Co, Ni, or their combinations) from Oswald ripening and agglomeration. [26,30] Here, we report a scalable method for the atmospheric pressure (AP)CCVD of CNTs on Al foils to make hybrid electrodes for EDLCs. We demonstrate the influence of surface topography of the Al foil for the growth of CNTs, their alignment, and adhesion to the current collector.…”

Section: Introductionmentioning

confidence: 99%

“…Apparently, the main reason is that the low melting point of Al (660 8C) prevents it from successfully withstanding the high temperatures employed in thermal CCVD. [25,26] CCVD of aligned CNTs at low temperature requires both a suitable hydrocarbon and a high surface concentration of active catalyst particles for their growth. [27] Acetylene seems to be the best choice because it is thermodynamically the least stable hydrocarbon at low temperatures (up to 1000 K).…”

Section: Introductionmentioning

confidence: 99%

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Application of Carbon Nanotubes Directly Grown on Aluminum Foils as Electric Double Layer Capacitor Electrodes

Khavrus

Weiser

Fritsch

et al. 2012

Chemical Vapor Deposition

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Carbon nanotubes (CNTs) are directly grown by catalytic (C)CVD on Al foils with various surface morphologies to make hybrid electrodes for electric double layer capacitors (EDLCs). A simple drop-coating procedure is used for the deposition of the Fe/Al-based catalyst. It is found that the surface topography of the Al foil is a governing factor for the growth of CNTs, their alignment, and adhesion to the current collector. Prepared electrodes achieve a specific capacitance up to 11.2 F g À1 , which is found to be weakly sensitive to the alignment of the CNTs. Discussion of parameters that influence the properties of the resulting EDLCs is presented.

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“…As shown in Fig. 4, the new data from Jakubinek 26 and Yang 27 were plotted and compared with transformed equations from Equation (8), respectively. It should be pointed out that the absolute values of those two original data sets differ by about 2 orders of magnitude.…”

Section: A the Dimensionless K-t Equation And Its Evaluationmentioning

confidence: 99%

A practical dimensionless equation for the thermal conductivity of carbon nanotubes and CNT arrays

Chen

Huang

2014

AIP Advances

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Experimental results reported in the last decade on the thermal conductivity of carbon nanotubes (CNTs) have shown a fairly divergent behavior. An underlying intrinsic consistency was believed to exist in spite of the divergence in the thermal conductivity data of various CNTs. A dimenisonless equation that describes the temperature dependence of thermal conductivity was derived by introducing reduced forms relative to a chosen reference point. This equation can serve as a practical approximation to characterize the conductivity of individual CNT with different structural parameters as well as bulk CNT arrays with different bundle configurations. Comparison of predictions by the equation and historical measurements showed good agreements within their uncertainties.

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Thermal and electrical conductivity of tall, vertically aligned carbon nanotube arrays

Cited by 130 publications

References 23 publications

Experimental Reconstruction of Thermal Parameters in CNT Array Multilayer Structure

Experimental Reconstruction of Thermal Parameters in CNT Array Multilayer Structure

Application of Carbon Nanotubes Directly Grown on Aluminum Foils as Electric Double Layer Capacitor Electrodes

A practical dimensionless equation for the thermal conductivity of carbon nanotubes and CNT arrays

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