Pillared Boron Nitride: mechanical and thermal properties of a new 3D nanostructure
Rouzbeh Shahsavari (Rice University), Navid Sakhavand (Rice University)
Synthesis, Characterization, and Modeling of Low-Dimensional Nanomaterials
Wed 10:45 - 12:15
Salomon 202
Boron nitride (BN) is a wide band gap IIIV compound consisting of equal proportions of B and N atoms. Hexagonal BN (h-BN) and Boron nitride nanotube (BNNT) are comprised of alternating B and N atoms in a honeycomb arrangement similar to graphene and carbon nanotubes (CNT) structures, respectively. One of the key specifications of these low dimensional BN structures is their direction-dependent properties. h-BN exhibits excellent in-plane mechanical strength due to strong covalent bonds between B-N atoms but weak out-of-plane strength because of interlayer van der Waals interactions. Similarly, BNNT shows great 1D properties along the tube axis. Here, we report a new hybrid structure by combining h-BN and BNNT allotropes to computationally create 3D BN structures, which would bring new opportunities to further exploit BN properties and enable potential applications in thermal management, gas storage, and structural composites. By employing atomistic simulations, full elastic (stiffness tensor) and inelastic behavior until rupture as well as and thermal conductivity coefficients are obtained, which feature the anisotropic mechanical and thermal transport behavior of PBN. This nano-porous material is favored over its 1-D and 2-D constituents in the unique characteristics stemmed from its 3-D nanostructure. We show that variation of mechanical and thermal properties with size in different dimensions makes PBN a flexible, tunable material.