2004 Fiscal Year Final Research Report Summary
Measurements of the Thermal Conductivity and Electrical Conductivity of Carbon Nanofibers
| Project/Area Number |
15360114
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Thermal engineering
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| Research Institution | KYUSHU UNIVERSITY |
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Principal Investigator |
FUJII Motoo Kyushu University, Institute for Materials Chemistry and Engineering, Professor, 先導物質化学研究所, 教授 (90038589)
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| Co-Investigator(Kenkyū-buntansha) |
ZHANG Xing Kyushu University, Institute for Materials Chemistry and Engineering, Associate Professor, 先導物質化学研究所, 助教授 (40236823)
MOCHIDA Isao Kyushu University, Institute for Materials Chemistry and Engineering, Professor, 先導物質化学研究所, 特任教授 (20037758)
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| Project Period (FY) |
2003 – 2004
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| Keywords | Carbon nanofiber / Carbon nanotube / Thermal Conductivity / Electrical Conductivity / Microstructure |
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| Research Abstract |
(1)Measurements of the thermal conductivity of individual carbon fibers under different manufacturing conditions have been carried out. The effects of heat treatment temperature on the thermal conductivity have been clarified. The measured results show that the thermal conductivity greatly increases as the heat treatment temperature increases, and even up to several hundred times when the temperature is changed from 700℃ to 3000℃. The effects of heat treatment temperature on the microstructure of the cross-sectional surface of individual carbon fibers have been clarified.
(2)Measurements of the thermal conductivity and thermal diffusivity of packed carbon fibers at the different packed densities have been carried out. The thermal conductivity of the packed carbon fibers depends greatly on the packed density. The relationship between the thermal conductivity and the packed density has been clarified, and further the electrical conductivity of the packed carbon fibers has been measured ac
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curately.
(3)With the help of Micro-Electro-Mechanical Systems (MEMS), the probe used for carbon fibers has been microminiaturized to be applicable for measurements of the nanoscale samples. The nanofilm probe with 100 nm wide, 40 nm thick, and 6 μm long in the part of hot wire has been micro fabricated successfully. It has been confirmed that this nanoprobe can be used to measure the thermal conductivity of a carbon nanotube with its diameter at the dozens of nanometers.
(4)By using local focused electron beam irradiation inside a manipulation SEM of the National Institute of Advanced Industrial Science and Technology, one end of the carbon nanotube has been successfully attached to the center part of the nanoprobe to make a T-type nanosensor.
(5)Before measuring the thermal conductivity of individual carbon nanotubes, the thermal conductivity and electrical conductivity of the platinum nanofilm must be known and these values have been measured accurately. The both of present measured values for the nanofilm are found to be less than half of the bulk values.
(6)Using the variable temperature liquid nitrogen cryostat, the thermal conductivity of individual nanotubes with different diameters has been measured in the range of 100-320 K. It has been confirmed that the carbon nanotube has an asymptotic value of about 2000 W/mK near 300 K.
(7)Uncertainty analysis for the measurements of the thermal conductivity of carbon nanofiber and nanotube has been performed. The applicability of the present method has been confirmed and some new knowledge on the measured values has been published. Less
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Research Products
(12 results)
