Thermal properties of polymer‐derived ceramic reinforced with boron nitride nanotubes

Abstract

We report the thermal properties of boron nitride nanotube (BNNT) reinforced ceramic composites using the polymer derived ceramic (PDC) processing route. The nano‐composites had a BNNT loading of up to 35.4 vol.%. TGA results showed that nano‐composites have good thermal stability up to 900°C in air. BNNTs in nano‐composites survived in an oxidizing environment up to 900°C, revealing that nano‐composites can be used for high temperature applications. Thermal conductivity of PDC reinforced with 35.4 vol.% BNNT was measured as 4.123 W/(m·K) at room temperature, which is a 2100 % increase compared to that of pristine PDC. The thermal conductivity value increases with the increase of BNNT content. A thermal conductivity percolation phenomenon appeared when the BNNT content increased to 36 ± 5 vol.%. The results of this study showed that BNNTs could effectively improve the thermal conductivity of PDC materials. BNNT reinforced PDC could be used as thermal structural materials in a harsh environment at temperatures up to 900°C.

Hybrid Ni–Boron Nitride Nanotube Magnetic Semiconductor—A New Material for Spintronics

“…An absorbance peak occurs at 217 nm. Based on the wavelength, the band gap energy of as-synthesized BNNTs was found to be 5.7 eV, which very well puts them in the category of wide-bandgap semiconductors 30 , 31 and this value was found to be in agreement with that in the literature, 32 − 34 but the band gap energy for pure BNNTs was found to be closer to 6.0 eV. 4 , 35 This decrease in bandgap energy is due to nickel which imparts some conductivity to the nanotubes.…”

Dielectric properties of polymer‐derived ceramic reinforced with boron nitride nanotubes

“…The electrical resistivity of PDC is associated with the sp 2 carbon (G) in the PDC matrix. A percolation network of sp 2 carbon will form when the pyrolysis temperature is above 1400°C 18,54 . In this work, because of the low pyrolysis temperature (1000°C), the percolation network is not formed, which results in a high electrical resistivity of the PDC matrix.…”

“…Boron nitride nanotubes (BNNTs) have a wide‐band gap and a similar structure to carbon nanotubes (CNTs) 18‐21 . BNNTs have attractive properties, such as excellent mechanical properties, 22,23 high thermal conductivity, 24‐29 and hydrogen storage capability 30,31 .…”

“…BNNTs have attractive properties, such as excellent mechanical properties, 22,23 high thermal conductivity, 24‐29 and hydrogen storage capability 30,31 . BNNTs also show significant superiority in thermal and chemical stability compared to CNTs in air 18,32,33 . Especially, BNNTs possesses perfect electrical insulation 34‐36 and superb oxidation resistance, 37 which can be used to adjust the real relative permittivity and dielectric loss tangent of materials 38 .…”

“…Especially, BNNTs possesses perfect electrical insulation 34‐36 and superb oxidation resistance, 37 which can be used to adjust the real relative permittivity and dielectric loss tangent of materials 38 . BNNTs therefore are excellent candidates 39 for reinforcing polymers, 38,40‐45 ceramics, 18,36,46‐49 and metals 50 …”