Formation of Liquid Crystalline Order and Its Effect on Thermal Conductivity of AlN/Liquid Crystalline Epoxy Composite

The liquid crystalline (LC) order was introduced on aluminum nitride particles by the surface effect to increase the thermal conductivities of aluminum nitride/LC epoxy composites. X-ray diffraction and grazing incidence small-angle X-ray scattering analyses revealed that the LC epoxy resin cured on the surface of an α-Al₂O₃ substrate formed homeotropically aligned smectic layers to increase the thermal conductivity. Therefore, thermally treated aluminum nitride particles, which formed α-Al₂O₃ layers on their surfaces, were applied to prepare the composites with high thermal conductivity. The thermal conductivities of the resulting composites were 11–36% higher than those with the composites prepared using untreated aluminum nitride particles.