H-BN nanostructures; synthesis and applications

Official URL: https://risc01.sabanciuniv.edu/record=b2711491_(Table of contents)

Exploring boron nitride (BN) structures at materials science carries a great potential for evolving technology. BN nano/microstructures consist of alternating B and N atoms with sp2 and sp3 hybridization that provides excellent mechanical, thermal, thermomechanical, and electrical properties with strong chemical and thermal stability. Lately, special attention has been given to BN nano/microstructures such as BN nanotubes (BNNT), BN microfibers (BN-MF), and BN nano/microparticles (BN-NP, BN-MP). Incorporating the properties as mentioned earlier BN nano/microstructures with polymers and/or other ceramics can provide strong structural composites, dielectric insulating materials, etc. However, due to difficulties in the synthesis of the BN nano/microstructures and challenges encountered during the dispersion of the BN inside the composite matrix inhibit the comprehensive research. Herein, we show two possible applications of the BN nano/microstructures as well as a novel, low-cost synthesis method for the synthesis of boron nitride nanotubes BNNT. We found that decoration of SiC fiber surfaces with “fuzzy fiber” BNNTs can lead to increased interfacial shear strength (IFSS) that can result in composites with better mechanical properties. Moreover, we have evaluated the dielectric performance of the BN/Resin composites and showed that both the dielectric constant and the dielectric loss of the composites lower significantly whereas the glass transition temperature of the composites increased. Finally, we have proposed a modified chemical vapor deposition (CVD) method that utilizes colemanite as boron precursor and sulfur-molecules to increase the catalytic activity of the Fe2O3 catalyst. Our results showed that, with the addition of thiophene, BNNT synthesis is achievable at 1050 °C. Our works have shown that BN nano/microstructures have a wide range of applications from CMCs to dielectric insulators and synthesis of BNNTs can be accomplished in a low-cost, environmentally friendly system.