Study on preparation and field induction mechanism of organic silicon composites based on aligned carbon nanotubes

Abstract High thermal conductivity materials are an urgent need for high power, microelectronic components and equipment, but are limited by low thermal conductivity of the traditional silicone materials. 4‐Cyano‐4′‐n‐octyl biphenyl (8OCB) was synthesized to modify carbon nanotubes, and silicone was used as the matrix. In the curing process of the composite, an electric field was applied and the liquid crystal induced the orientation of carbon nanotubes in the direction of 8OCB liquid crystal. The morphology, structure and properties of modified carbon nanotubes and composites were characterized by Fourier transform infrared spectroscopy, polarized microscopy, transmission electron microscopy, thermal conductivity, and so on. The 8OCB liquid crystal can improve the dispersion of carbon nanotubes in silicone composites. When the mass fraction of multiwalled carbon nanotubes (MWCNTs) was 11 wt%, the thermal conductivity of 8OCB‐MWCNTs/silicone composite after electric field was 2.39 W/(m K), which is 6.4 times that of MWCNTs/silicone composite after electric field and 15.5 times that of pure silicone matrix. A method to obtain highly ordered filled thermal conductive materials by applying an electric field to induce the orientation of carbon nanotubes is demonstrated.