Thermal conductivity of carbon nanotube superlattices: Comparative study with defective carbon nanotubes

2018 ◽  
Vol 27 (2) ◽  
pp. 026501 ◽  
Author(s):  
Kui-Kui Zhou ◽  
Ning Xu ◽  
Guo-Feng Xie
Keyword(s):  
Thermal Conductivity ◽  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Comparative Study

A closed-form model for estimating the effective thermal conductivities of carbon nanotube–polymer nanocomposites

2018 ◽  
Vol 233 (8) ◽  
pp. 2909-2919 ◽  
Author(s):  
Reza Moheimani ◽  
M Hasansade
Keyword(s):  
Thermal Conductivity ◽  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Closed Form ◽  
Polymer Nanocomposites ◽  
Micromechanical Model ◽  
Polymer Nanocomposite ◽  
Interfacial Thermal Resistance ◽  
Full Potential ◽  
Thermal Conductivities

This paper describes a closed-form unit cell micromechanical model for estimating the effective thermal conductivities of unidirectional carbon nanotube reinforced polymer nanocomposites. The model incorporates the typically observed misalignment and curvature of carbon nanotubes into the polymer nanocomposites. Also, the interfacial thermal resistance between the carbon nanotube and the polymer matrix is considered in the nanocomposite simulation. The micromechanics model is seen to produce reasonable agreement with available experimental data for the effective thermal conductivities of polymer nanocomposites reinforced with different carbon nanotube volume fractions. The results indicate that the thermal conductivities are strongly dependent on the waviness wherein, even a slight change in the carbon nanotube curvature can induce a prominent change in the polymer nanocomposite thermal conducting behavior. In general, the carbon nanotube curvature improves the nanocomposite thermal conductivity in the transverse direction. However, using the straight carbon nanotubes leads to maximum levels of axial thermal conductivities. With the increase in carbon nanotube diameter, an enhancement in nanocomposite transverse thermal conductivity is observed. Also, the results of micromechanical simulation show that it is necessary to form a perfectly bonded interface if the full potential of carbon nanotube reinforcement is to be realized.

Carbon nanotube-copper exhibiting metal-like thermal conductivity and silicon-like thermal expansion for efficient cooling of electronics

Nanoscale ◽  
2014 ◽  
Vol 6 (5) ◽  
pp. 2669-2674 ◽  
Author(s):  
Chandramouli Subramaniam ◽  
Yuzuri Yasuda ◽  
Satoshi Takeya ◽  
Seisuke Ata ◽  
Ayumi Nishizawa ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Carbon Nanotubes ◽  
Thermal Expansion ◽  
Thermal Properties ◽  
Carbon Nanotube ◽  
Cooling Of Electronics

A composite that synergistically combines the best thermal properties of carbon nanotubes and copper is developed for efficient cooling of microelectronics.

Thermal conductivity and flammability of multiwall carbon nanotube/polyurethane foam composites

2016 ◽  
Vol 53 (2) ◽  
pp. 215-230 ◽  
Author(s):  
JJ Espadas-Escalante ◽  
F Avilés ◽  
PI Gonzalez-Chi ◽  
AI Oliva
Keyword(s):  
Thermal Conductivity ◽  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Polyurethane Foam ◽  
Fire Behavior ◽  
Multiwall Carbon Nanotubes ◽  
Propagation Speed ◽  
Interfacial Thermal Resistance ◽  
Multiwall Carbon Nanotube ◽  
Multiwall Carbon

The thermal conductivity and fire response of multiwall carbon nanotube/polyurethane foam composites are investigated for ∼45 kg/m3 foams with multiwall carbon nanotube concentrations of 0.1, 1, and 2 wt.%. The thermal conductivity of such nanocomposites shows a modest increase with increased multiwall carbon nanotube content, which is explained by a high value of interfacial thermal resistance, as predicted by existent thermal models. A strong correlation between multiwall carbon nanotube content, foam’s cellular morphology, and fire behavior was observed. The flame propagation speed increases with the addition of 0.1 wt.% multiwall carbon nanotubes and then reduces as the multiwall carbon nanotube content increases. The mass lost after flame extinction reduces with the addition of multiwall carbon nanotubes, suggesting an increased resistance to flame attack due the multiwall carbon nanotube presence.

Thermal Conductivity and Specific Heat Capacity of Carbon Nanotube Bundles

2007 ◽  
Author(s):  
John Shelton ◽  
Frank Pyrtle
Keyword(s):  
Thermal Conductivity ◽  
Carbon Nanotubes ◽  
Heat Capacity ◽  
Carbon Nanotube ◽  
Specific Heat ◽  
Specific Heat Capacity ◽  
Element Analysis ◽  
Single Walled Carbon ◽  
Nanotube Bundles ◽  
Dynamics Simulations

Carbon nanotubes (CNTs) have been thoroughly documented to demonstrate superior heat transfer properties. It has also been determined that these properties decrease substantially as overall dimensions increase from the nanoscale to the microscale. Using non-equilibrium molecular dynamics simulations and finite element analysis, the influence of both internal and external thermal boundary resistance effects on the thermal conductivity and specific heat capacity of single walled carbon nanotube bundles were investigated. Comparisons were made between accepted property values for single CNTs and for CNT bundles. Also, energy transfer between varying sized bundles of single-walled carbon nanotubes (SWCNTs) and a surrounding pressure-driven Lennard-Jones (LJ) fluid were calculated.

Role of rheology in tunning thermal conductivity of polyamide 12/polyamide 6 composites with a segregated multiwalled carbon nanotube network

2017 ◽  
Vol 52 (18) ◽  
pp. 2549-2557 ◽  
Author(s):  
Laura Arboleda-Clemente ◽  
Xoán García-Fonte ◽  
María-José Abad ◽  
Ana Ares-Pernas
Keyword(s):  
Thermal Conductivity ◽  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Thermal Diffusivity ◽  
Multiwalled Carbon Nanotubes ◽  
Polyamide 6 ◽  
Multiwalled Carbon ◽  
Polyamide 12 ◽  
Nanotube Composites ◽  
Carbon Nanotube Network

Effect of multiwalled carbon nanotubes in thermal conductivity of an immiscible blend of polyamides, 50/50 (wt%/wt%) polyamide 12/polyamide 6, was analyzed as function of nanofiller amount and temperature. Effect of the molding temperature in the structure of conductive network was investigated by rheology. Data show that 5 vol% multiwalled carbon nanotubes caused an increase of 41% in thermal diffusivity and 78% in thermal conductivity respect to polyamide blend values. Thermal conductivity improvement could be described by percolation theory, with a low threshold composition (φc = 0.09 vol% carbon nanotube). Fitting parameters obtained from Agari’s adjustment model show that polyamides structure is not affected by carbon nanotubes and the nanofillers can easily form conductive paths in the polyamide 12/polyamide 6 matrix. The temperature increase facilitates nanofiller dispersion causing the formation of a denser carbon nanotube network and rising the thermal diffusivity of carbon nanotube composites with low percolation level, as was proved on annealed samples at 255℃.

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