Robust Nanocomposite Films with High Dielectric Insulation from Boron Nitride Nanosheet and Aramid Nanofiber

With the rapid development of modern electrical equipment, nanocomposite films with high dielectric strength, mechanical properties, and thermal conductivity exhibit higher requirements. In this work, aramid nanofibers (ANFs) are obtained by deprotonation and mixed with (3-Aminopropyl) silane triol modified boron nitride nanosheets (aBNNs) to form a homogeneous suspension. The dense aBNNs/ANFs nanocomposite films are prepared by vacuum filtration and high-temperature hot pressing, and the nanocomposite films' mechanical properties, thermal conductivity, and electrical insulation properties are characterized. Results show that the nanocomposite film has excellent mechanical properties (breaking strength 238 MPa) and insulation properties (dielectric strength and volume resistance can reach 156 kV mm −1 and 6.95 × 10 16 Ωcm, respectively). The nanocomposite film is promising for applications in miniaturized and flexible electronic devices, and high-voltage electrical insulation equipment.