 |
Optimizing the assembly structure of carbon nanotubes through multiple ways to form three-dimensional network connections significantly improves the thermal conductivity of carbon nanotube composites.
Carbon nanotubes have an extremely high axial thermal conductivity and are therefore highly expected in high-power electronic device heat sink materials. However, its small size characteristics severely restrict its practical application, and the contact resistance and contact thermal resistance between carbon nanotubes and their composite matrix are large, so that the thermal conductivity of existing carbon nanotube composite materials is uniform. It is far from people’s expectations.
The research group of Li Qingwen, a member of the Advanced Materials Department of the Suzhou Institute of Nanotechnology and Nanobionics, Chinese Academy of Sciences, used the macro-sized carbon nanotube powder as a basis to carry out the functionalization of different groups and combined it with a commercial thermal grease. The effect of functionalization on the dispersion of carbon nanotubes in silicone grease and its infiltration with silicone grease was investigated. It was found that negatively charged carboxylated carbon nanotubes on the surface can be dispersed in a high concentration in the grease and form good heat conduction. The three-dimensional network significantly reduces the heat transfer resistance of the thermal grease.
On this basis, for the purpose of designing the three-dimensional heat-conducting network structure of carbon nanotubes, a flexible carbon nanotube paper with an ideal three-dimensional network structure was prepared by controlling the length and diameter of the carbon nanotubes and their heat transfer resistance. It can be lower than thermal grease and commercial heat-dissipating graphite sheet, and has solid self-supporting characteristics. When it is used as a thermal interface material, high-efficiency heat transfer can be achieved without contaminating the surface of the device.
Due to the low density of the pure carbon nanotube heat-conducting network and the large number of carbon nanotube overlaps, the thermal conductivity and electrical conductivity are still lower than people's expectations. For this reason, highly conductive, highly thermally conductive copper nanowires were introduced into carbon nanotube paper. The thermal conductivity of the interpenetrating three-dimensional network composed of two kinds of nanowires can be increased to 10 W/(m·K) and a conductivity of more than 105 S/m can be realized, which is favorable for its application in microelectronic interconnection and thermal interface materials.
Related research work has been published in Journal of Physical Chemistry C (2012, 116, 3903−3909), Carbon (DOI: 10.1016/j.carbon.2013.05.030), Applied Surface Science (doi:10.1016/j.apsusc.2013.06. 139), Materials Sciences and Applications (accepted) and other academic journals.
This study was supported by the National Natural Science Foundation of China (No. 21203238, No. 10834004), the Ministry of Science and Technology 973 Program (No.2010CB934700), the Jiangsu Provincial Cooperation of Industry, University, and Research Institute (No. BY2011178) and the Jiangsu Provincial International Cooperation Project (No.BZ2011049 ) And other funding.
Pvc Moulding Divison,Moulding Division,Pvc Extrusion Mould,Pvc Extrusion Moulding Starter
TAISHAN CITY WANAN CABLE CO.,LTD , https://www.tswanan.com