The thermal conductivity of an epoxy composite with Cu foam as the primary filler and functionalized with multi-walled carbon nanotubes (MWCNTs) is shown to reach 0.62 W/mK, which is 313% higher compared to the untreated epoxy. This enhancement is attributed to the increased interfacial affinity due to the coating with 3-mercaptopropyl trimethoxysilane (MPTMS) and the subsequent construction of a more intricate thermal conduction pathway due to the uniform dispersion of MWCNTs. In detail, the Cu nanoparticles (CuNPs) are attached to the thiol groups of MPTMS to provide more interfacial affinity between the Cu foam and the MWCNTs. The morphology of the functionalized filler inside the epoxy matrix is characterized by field emission scanning electron microscopy (FE-SEM) of the fractured composite surface, and the successful surface treatment is confirmed by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The enhanced thermal property of the composite fabricated in this study makes it a promising thermal interface material for electronic devices.

고방열 특성의 고분자 복합소재를 위하여 Cu폼과 Cu 나노입자가 부착된 MWCNT가 함께 첨가된 에폭시 복합체를 제작하였다. 고분자 내에서의 MWCNT의 분산성 향상을 위해 3-mercaptopropyl trimethoxysilane(MPTMS)를 이용하여 표면처리를 진행하였다. 또한 Cu폼과의 계면친화성을 위해 Cu 나노입자를 MWCNT의 표면에 부착하여 기존 에폭시와 비교하여 높은 열전도도를 확인하였다. 이러한 열전도도 증가는 MPTMS의 코팅으로 인한 MWCNT의 분산성 향상과 보다 복잡한 열전도 통로의 형성 때문이며 이러한 현상은 주사전자현미경과 FTIR, XRD, XPS 등을 통해 확인되었다.

Keywords: multi-walled carbon nanotube, surface modification, thermal conductivity, 3D structure, epoxy