Metallic Nanowire-Polymer Composite as Thermal Interface Material
Recently, we have demonstrated that the elongated metallic nanowires and nanowire based composites can act as thermal conduit between two surfaces and thereby able to transfer heat more efficiently as compared to carbon nanotube based composite materials . However, it has been observed that heat transport through these one dimensional filler materials is a complex subject of intensive research, which includes different thermal transport mechanism depending on constituent material (whether it is an electrical conductor, semiconductor or insulator) as well its size, shape and the crystallinity . This heat transfer mechanism was explained with a modified effective medium formulation based on Nan’s model . Furthermore, it has been observed that modulus of the nanocomposite plays a vital role in the transferring heat when pressed between two surfaces and lower modulus composite conforms easily to the roughnesses of the mating surface .
In this work we investigate the thermal properties of metal (Cu and Sn) nanowire-polymer composites. The thermal diffusivity of the composites was measured using a Xenon flash thermal constant analyzer. A thermal impedance system is employed according to the modified ASTM D5470 standard to measure the thermal impedance of the composites. A thermal impedance of 9±1 °Cmm2W-1is achieved at a pressure of 100 kPa, which is 50% lower thermal impedance compared to the commercial TIM.
This work is financially supported by Enterprise Ireland under commercialization fund technology development program.Grant No. CFTD/2008/322.
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