Anomalous thermal conductivity enhancement in nanotube suspensions
TL;DR: In this paper, the authors have produced nanotube-in-oil suspensions and measured their effective thermal conductivity, which is anomalously greater than theoretical predictions and is nonlinear with nanotubes loadings.
Abstract: We have produced nanotube-in-oil suspensions and measured their effective thermal conductivity. The measured thermal conductivity is anomalously greater than theoretical predictions and is nonlinear with nanotube loadings. The anomalous phenomena show the fundamental limits of conventional heat conduction models for solid/liquid suspensions. We have suggested physical concepts for understanding the anomalous thermal behavior of nanotube suspensions. In comparison with other nanostructured materials dispersed in fluids, the nanotubes provide the highest thermal conductivity enhancement, opening the door to a wide range of nanotube applications.
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TL;DR: The thermal properties of carbon materials are reviewed, focusing on recent results for graphene, carbon nanotubes and nanostructured carbon materials with different degrees of disorder, with special attention given to the unusual size dependence of heat conduction in two-dimensional crystals.
Abstract: Recent years have seen a rapid growth of interest by the scientific and engineering communities in the thermal properties of materials. Heat removal has become a crucial issue for continuing progress in the electronic industry, and thermal conduction in low-dimensional structures has revealed truly intriguing features. Carbon allotropes and their derivatives occupy a unique place in terms of their ability to conduct heat. The room-temperature thermal conductivity of carbon materials span an extraordinary large range--of over five orders of magnitude--from the lowest in amorphous carbons to the highest in graphene and carbon nanotubes. Here, I review the thermal properties of carbon materials focusing on recent results for graphene, carbon nanotubes and nanostructured carbon materials with different degrees of disorder. Special attention is given to the unusual size dependence of heat conduction in two-dimensional crystals and, specifically, in graphene. I also describe the prospects of applications of graphene and carbon materials for thermal management of electronics.
5,189 citations
Cites background from "Anomalous thermal conductivity enha..."
... interface materials (TIMs). XI. Graphene and Carbon Based Composites The needs for improved TIMs in modern electronics and optoelectronics stimulated interest to carbon materials as fillers for TIMs [105, 106, 107, 108, 109, 110, 111, 112, 113]. Current TIMs are based on polymers or greases filled with thermally conductive particles such as silver, which require high volume fractions of filler (up to 70%) to achieve K of ~1-5 W/mK of the co...
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TL;DR: In this paper, the authors review thermal and thermoelectric properties of carbon materials focusing on recent results for graphene, carbon nanotubes and nanostructured carbon materials with different degrees of disorder.
Abstract: Recent years witnessed a rapid growth of interest of scientific and engineering communities to thermal properties of materials. Carbon allotropes and derivatives occupy a unique place in terms of their ability to conduct heat. The room-temperature thermal conductivity of carbon materials span an extraordinary large range – of over five orders of magnitude – from the lowest in amorphous carbons to the highest in graphene and carbon nanotubes. I review thermal and thermoelectric properties of carbon materials focusing on recent results for graphene, carbon nanotubes and nanostructured carbon materials with different degrees of disorder. A special attention is given to the unusual size dependence of heat conduction in two-dimensional crystals and, specifically, in graphene. I also describe prospects of applications of graphene and carbon materials for thermal management of electronics.
3,609 citations
TL;DR: In this article, the status of worldwide research in the thermal conductivity of carbon nanotubes and their polymer nanocomposites is reviewed, as well as the relationship between thermal conductivities and the micro- and nano-structure of the composites.
2,102 citations
TL;DR: A review on fluid flow and heat transfer characteristics of nanofluids in forced and free convection flows is presented in this article, where the authors identify opportunities for future research.
1,988 citations
Cites methods or result from "Anomalous thermal conductivity enha..."
...As compared with the existing experimental data [ 32 ], the proposed model provided reasonable agreement with adjusted thermal conductivity of CNTs....
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...Later, nanotube (multiwalled carbon nanotubes or MWNTs)-oil (α-olefin) mixtures were investigated by Choi et al. [ 32 ] to measure their effective thermal conductivity....
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...They found that the improvement of the thermal conductivity is slightly higher than that reported by Assael et al. [39], Xie et al. [33], and Wen and Ding [37], but much lower than that showed in Choi et al. [ 32 ]....
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...Choi et al. [ 32 ] MWNTs ∅25 × 50 µm oil exceed 250% at 1.0 vol% Biercuk et al. [34] SWNTs ∅3–30 epoxy 125% at 1.0 wt% Xie et al. [33] TCNTs ∅15 × 30 µm DW, EG, DE 19.6%, 12.7%, and 7.0% increase at 1.0 vol% for TCNT/DE, EG, and...
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...The results within Nan’s model [95] agree well with the experimental observations [ 32 ]....
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TL;DR: In this paper, the authors summarized the important published articles on the enhancement of the forced convection heat transfer with nanofluids, including simulations, simulations, and experimental results.
1,738 citations
References
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NEC1
TL;DR: Iijima et al. as mentioned in this paper reported the preparation of a new type of finite carbon structure consisting of needle-like tubes, which were produced using an arc-discharge evaporation method similar to that used for fullerene synthesis.
Abstract: THE synthesis of molecular carbon structures in the form of C60 and other fullerenes1 has stimulated intense interest in the structures accessible to graphitic carbon sheets. Here I report the preparation of a new type of finite carbon structure consisting of needle-like tubes. Produced using an arc-discharge evaporation method similar to that used for fullerene synthesis, the needles grow at the negative end of the electrode used for the arc discharge. Electron microscopy reveals that each needle comprises coaxial tubes of graphitic sheets, ranging in number from 2 up to about 50. On each tube the carbon-atom hexagons are arranged in a helical fashion about the needle axis. The helical pitch varies from needle to needle and from tube to tube within a single needle. It appears that this helical structure may aid the growth process. The formation of these needles, ranging from a few to a few tens of nanometres in diameter, suggests that engineering of carbon structures should be possible on scales considerably greater than those relevant to the fullerenes. On 7 November 1991, Sumio Iijima announced in Nature the preparation of nanometre-size, needle-like tubes of carbon — now familiar as 'nanotubes'. Used in microelectronic circuitry and microscopy, and as a tool to test quantum mechanics and model biological systems, nanotubes seem to have unlimited potential.
39,086 citations
Book•
01 Jan 1873
TL;DR: The most influential nineteenth-century scientist for twentieth-century physics, James Clerk Maxwell (1831-1879) demonstrated that electricity, magnetism and light are all manifestations of the same phenomenon: the electromagnetic field as discussed by the authors.
Abstract: Arguably the most influential nineteenth-century scientist for twentieth-century physics, James Clerk Maxwell (1831–1879) demonstrated that electricity, magnetism and light are all manifestations of the same phenomenon: the electromagnetic field. A fellow of Trinity College Cambridge, Maxwell became, in 1871, the first Cavendish Professor of Physics at Cambridge. His famous equations - a set of four partial differential equations that relate the electric and magnetic fields to their sources, charge density and current density - first appeared in fully developed form in his 1873 Treatise on Electricity and Magnetism. This two-volume textbook brought together all the experimental and theoretical advances in the field of electricity and magnetism known at the time, and provided a methodical and graduated introduction to electromagnetic theory. Volume 2 covers magnetism and electromagnetism, including the electromagnetic theory of light, the theory of magnetic action on light, and the electric theory of magnetism.
9,565 citations
Book•
01 Jan 1998
TL;DR: In this paper, an introductory textbook for graduate students and researchers from various fields of science who wish to learn about carbon nanotubes is presented, focusing on the basic principles behind the physical properties and giving the background necessary to understand the recent developments.
Abstract: This is an introductory textbook for graduate students and researchers from various fields of science who wish to learn about carbon nanotubes. The field is still at an early stage, and progress continues at a rapid rate. This book focuses on the basic principles behind the physical properties and gives the background necessary to understand the recent developments. Some useful computational source codes which generate coordinates for carbon nanotubes are also included in the appendix.
5,055 citations
TL;DR: In this paper, it was shown that a "nanofluid" consisting of copper nanometer-sized particles dispersed in ethylene glycol has a much higher effective thermal conductivity than either pure or pure glycol or even polyethylene glycol containing the same volume fraction of dispersed oxide nanoparticles.
Abstract: It is shown that a “nanofluid” consisting of copper nanometer-sized particles dispersed in ethylene glycol has a much higher effective thermal conductivity than either pure ethylene glycol or ethylene glycol containing the same volume fraction of dispersed oxide nanoparticles. The effective thermal conductivity of ethylene glycol is shown to be increased by up to 40% for a nanofluid consisting of ethylene glycol containing approximately 0.3 vol % Cu nanoparticles of mean diameter <10 nm. The results are anomalous based on previous theoretical calculations that had predicted a strong effect of particle shape on effective nanofluid thermal conductivity, but no effect of either particle size or particle thermal conductivity.
3,551 citations
3,019 citations