Size and temperature dependence of the specific heat capacity of carbon nanotubes

2006 ◽  
Vol 600 (18) ◽  
pp. 3633-3636 ◽  
Author(s):  
S.P. Hepplestone ◽  
A.M. Ciavarella ◽  
C. Janke ◽  
G.P. Srivastava
Author(s):  
I. N. Ganiev ◽  
S. E. Otajonov ◽  
N. F. Ibrohimov ◽  
M. Mahmudov

In the heat «cooling» investigated the temperature dependence of the specific heat capacity and thermodynamic functions doped strontium alloy AK1М2 in the range 298,15—900 K. Mathematical models are obtained that describe the change in these properties of alloys in the temperature range 298.15—900 K, as well as on the concentration of the doping component. It was found that with increasing temperature, specific heat capacity, enthalpy and entropy alloys increase, and the concentration up to 0.5 wt.% of the alloying element decreases. Gibbs energy values have an inverse relationship, i.e., temperature — decreases the content of alloying component — is up to 0.5 wt.% growing.


2009 ◽  
Vol 6 (5) ◽  
pp. 1200-1203 ◽  
Author(s):  
Mahmoud Jafari ◽  
Seyyed Farhad Masoudi ◽  
Majid Vaezzadeh ◽  
Leila Bohloli Oskoui

Author(s):  
John Shelton ◽  
Frank Pyrtle

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.


2014 ◽  
Vol 137 (1) ◽  
Author(s):  
Byeongnam Jo ◽  
Debjyoti Banerjee

The specific heat capacity of a carbonate salt eutectic-based carbon nanotube nanomaterial was measured in present study. Differential scanning calorimeter (DSC) was used to measure the specific heat capacity of the nanomaterials. The specific heat capacity value in liquid phase was compared with that of a pure eutectic. A carbonate salt eutectic was used as a base material, which consists of lithium carbonate and potassium carbonate by 62:38 molar ratio. Multiwalled carbon nanotubes (CNT) at 1% mass concentration were dispersed in the molten salt eutectic. In order to find an appropriate surfactant for synthesizing molten salt nanomaterials, three surfactants, sodium dodecyl benzene sulfonate (SDBS), sodium dodecyl sulfate (SDS), and gum arabic (GA), at 1% mass concentration with respect to the salt eutectic were added. In preparation of dehydrated nanomaterials, water was evaporated by heating vials on a hot plate. Three different temperature conditions (120, 140, and 160 °C) were employed to investigate the effect of dispersion homogeneity of the nanotubes in the base material on the specific heat capacity of the nanomaterials. It is expected that the amount of agglomerated nanotubes decreases with increase of evaporation temperature (shorter elapsed time for evaporation). The results showed that the specific heat capacity of the nanomaterials was enhanced up to 21% in liquid phase. Additionally, it was found that the specific heat capacity enhancement of the nanomaterials, which contained SDS, was more sensitive to the evaporation time. Also, it can be decided that GA is the most appropriate to disperse CNT into the aqueous salt solution. Finally, CNT dispersion was confirmed with scanning electron microscope (SEM) images for pre-DSC and post-DSC samples. Furthermore, theoretical predictions of the specific heat capacity were compared with the experimental results obtained in present study.


2012 ◽  
Vol 62 ◽  
pp. 34-39 ◽  
Author(s):  
C.A. Nieto de Castro ◽  
S.M.S. Murshed ◽  
M.J.V. Lourenço ◽  
F.J.V. Santos ◽  
M.L.M. Lopes ◽  
...  

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