Magnetic alignment of carbon nanotubes in polymers for enhanced thermal conductivity

With the rapid advancement of electronic devices, the demand for high-performance thermal interface materials (TIMs) to ensure integrated circuit reliability is increasing. Carbon nanotubes (CNTs), known for their exceptional thermal properties, are commonly used as additives in polymer matrices for composite TIMs. However, due to their random dispersion and lack of structural control, thermal conductivity improvements are limited, even at high content levels. In this study, we report a method for aligning CNTs within a polymer matrix using a magnetic field (0.3 T), leveraging the intrinsic diamagnetic properties of carbon nanotubes. This approach enables the preparation of composite materials with significantly enhanced thermal conductivity. Specifically, a thermal conductivity of up to 1.1 W m^-1 K^-1 was achieved at a low content of 10 wt% CNTs, and the thermal conductivity of CNT/F2311 was improved by 647% compared to that of F2311. Furthermore, cooling performance tests on heat sink fins incorporating this CNT/F2311 composite demonstrate a temperature reduction of 10.6 K compared to fins without CNTs, highlighting the potential for advanced thermal management applications in materials.