3-Omega Measurements of Vertically Oriented Carbon Nanotubes on Silicon

2005 ◽  
Vol 128 (11) ◽  
pp. 1109-1113 ◽  
Author(s):  
X. Jack Hu ◽  
Antonio A. Padilla ◽  
Jun Xu ◽  
Timothy S. Fisher ◽  
Kenneth E. Goodson
Keyword(s):  
Carbon Nanotubes ◽  
Phase Change ◽  
Silicon Substrate ◽  
Phase Change Materials ◽  
Interface Structure ◽  
Next Generation ◽  
Thermal Interface ◽  
Omega Method ◽  
3 Omega ◽  
3 Omega Method

An exploratory thermal interface structure, made of vertically oriented carbon nanotubes directly grown on a silicon substrate, has been thermally characterized using a 3-omega method. The effective thermal conductivities of the carbon nanotubes (CNT) sample, including the effects of voids, are found to be 74W∕mK to 83W∕mK in the temperature range of 295K to 323K, one order higher than that of the best thermal greases or phase change materials. This result suggests that the vertically oriented CNTs potentially can be a promising next-generation thermal interface solution. However, fairly large thermal resistances were observed at the interfaces between the CNT samples and the experimental contact. Minimizing these contact resistances is critical for the application of these materials.

scholarly journals A Unique Strategy for Polyethylene Glycol/Hybrid Carbon Foam Phase Change Materials: Morphologies, Thermal Properties, and Energy Storage Behavior

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2011 ◽  
Author(s):  
Xiaolong Su ◽  
Shikui Jia ◽  
Guowei Lv ◽  
Demei Yu
Keyword(s):  
Carbon Nanotubes ◽  
Polyethylene Glycol ◽  
Energy Storage ◽  
Phase Change ◽  
Thermal Energy ◽  
Phase Change Materials ◽  
Carbon Foam ◽  
Chemical Structures ◽  
Walled Carbon Nanotubes ◽  
Hybrid Carbon

Polyethylene glycol (PEG)/hybrid carbon foam (CF) phase change materials (PCMs) were prepared by integrating PEG into CF via dynamic-vacuum impregnation. The hybrid CF was first synthesized by mixtures of graphene oxide (GO) and carbon nanotubes (CNTs) with different volume ratios. The morphologies, chemical structures, thermal conductivities, shape-stabilization levels, and photo-thermal energy conversion levels of these composite PCMs were characterized systematically. The prepared composite PCMs exhibited good shape-stabilization levels and showed their original shapes without any PEG leakage. It was found that the polyethylene glycol/carbon foam with multi-walled carbon nanotubes (PEG/MCF) composite PCMs had a better shape-stable performance below the temperature of 250 °C, and the thermal conductivity of the PEG/MCF composite PCMs reached as high as 1.535 W/(mK), which was obviously higher than that of polyethylene glycol/carbon foam with single-walled carbon nanotubes (PEG/SCF, 1.159 W/(mK)). The results of the photo-thermal simulation tests showed that the composite PCMs had the ability to absorb light energy and then convert it to thermal energy, and the maximum thermal energy storage efficiency of the PEG/MCF composite PCMs and the PEG/SCF composite PCMs was 92.1% and 90.6%, respectively. It was considered that a valuable technique to produce high-performance composite PCMs was developed.

scholarly journals Expanded Graphite/Paraffin/Silicone Rubber as High Temperature Form-stabilized Phase Change Materials for Thermal Energy Storage and Thermal Interface Materials

Materials ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 894 ◽  
Author(s):  
Yafang Zhang ◽  
Wang Li ◽  
Juhua Huang ◽  
Ming Cao ◽  
Guoping Du
Keyword(s):  
Energy Storage ◽  
Phase Change ◽  
Latent Heat ◽  
Silicone Rubber ◽  
Phase Change Materials ◽  
Expanded Graphite ◽  
Thermal Interface Materials ◽  
Thermal Interface ◽  
Excellent Thermal Stability ◽  
Interface Materials

In this work, expanded graphite/paraffin/silicone rubber composite phase-change materials (PCMs) were prepared by blending the expanded graphite (EG), paraffin wax (PW) and silicone rubber (SR) matrix. It has been shown that PW fully penetrates into the three dimensional (3D) pores of EG to form the EG/PW particles, which are sealed by SR and evenly embedded in the SR matrix. As a result of the excellent thermal stability of SR and the capillary force from the 3D pores of EG, the EG/PW/SR PCMs are found to have good shape stability and high reliability. After being baked in an oven at 150 °C for 24 h, the shape of the EG/PW/SR PCMs is virtually unchanged, and their weight loss and latent heat drop are only 7.91 wt % and 11.3 J/g, respectively. The latent heat of the EG/PW/SR composites can reach up to 43.6 and 41.8 J/g for the melting and crystallizing processes, respectively. The super cooling of PW decreased from 4.2 to 2.4 due to the heterogeneous nucleation on the large surface of EG and the sealing effect of the SR. Meanwhile, the thermal conductivity of the EG/PW/SR PCMs reaches 0.56 W·m−1·K−1, which is about 2.8 times and 3.73 times of pure PW and pristine SR, respectively. The novel EG/PW/SR PCMs with superior shape and thermal stabilities will have a potential application in heat energy storage and thermal interface materials (TIM) for electronic devices.

Effect of expanded graphite and carbon nanotubes on the thermal performance of stearic acid phase change materials

2017 ◽  
Vol 52 (20) ◽  
pp. 12370-12379 ◽  
Author(s):  
Xiaomin Cheng ◽  
Ge Li ◽  
Guoming Yu ◽  
Yuanyuan Li ◽  
Jiaqiang Han
Keyword(s):  
Carbon Nanotubes ◽  
Stearic Acid ◽  
Phase Change ◽  
Thermal Performance ◽  
Phase Change Materials ◽  
Expanded Graphite

I23 Thermal conductivity measurements of thin films by using The 3 omega method

2008 ◽  
Vol 2008.61 (0) ◽  
pp. 291-292
Author(s):  
Makoto TAKIISHI ◽  
Saburo TANAKA ◽  
Hiroshi TSUKAMOTO ◽  
Koji MIYAZAKI
Keyword(s):  
Thin Films ◽  
Thermal Conductivity ◽  
Conductivity Measurements ◽  
Omega Method ◽  
3 Omega ◽  
3 Omega Method
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