| [Boron-related materials, preparation, structure and application] Formation of New Architecture of Boron Based Composite Powders under Effect of Concentrated Light Formation of New Architecture of Boron Based Composite Powders under Effect of Concentrated Light Lina Sartinska1; Izabella Timofeeva1; Tarik Eren2; Anatoly Efimov3; Olena Fecenko4; 1FRANTSEVICH INSTITUTE FOR PROBLEMS OF MATERIALS SCIENCE, NAS OF UKRAINE, Kyiv, Ukraine; 2YILDIZ TECHNICAL UNIVERSITY, ISTANBUL, TURKEY, Istanbul, Turkey; 3LOS ALAMOS NATIONAL LABORATORY, LOS ALAMOS, USA, Los Alamos, United States; 4INSTITUTE OF PHYSICS, NASU, KYIV, UKRAINE, Kyiv, Ukraine; PAPER: 261/Nanomaterials/Regular (Oral) SCHEDULED: 17:10/Sat. 26 Oct. 2019/Ambrosia B (77/RF) ABSTRACT: Nanocomposites are materials of the twenty-first century [1]. Because nanocomposites offer the possibility of combining many desired properties, they are expanding their potentials in aerospace applications and in future space missions. Due to its mechanical, thermal, electrical, chemical and biodegradable properties, and low weight requirements, boron nitride based nanocomposites are the most prospective for use in aerospace applications. Therefore, boron based composite powders of new architecture will increase the spectrum of properties of nano-enabled composites. The composite powders of new architecture are produced under effect of concentrated light in an optical furnace for aerospace applications. Concentrated light heating of an optical furnace has a number of advantages such as high heating and cooling rates, versatility, ability to adjust temperature profile along each axis, and adaptability to maximum operating temperatures and environments. Moreover, the high-flux optical furnace presents one of cleanest energy sources available for nanotechnology and this technique is appropriate for both conducting and non-conducting materials [1]. Transformation of boron nitride and boron powders with 25 wt. % indium, aluminum, coper, iron or nickel added in flow of nitrogen was considered. This demonstrated the effect of temperature distribution and temperature gradients within an experimental camera on architecture, phase composition and other properties of obtained powdered materials. The presence of a catalyst in boron nitride powder during transformation under effect of concentrated light promotes formation of nanostructures. Formation of a new architecture of nanostructures can be explained in framework of “gaseous model” which was based on the evolution of the bubble during heating in an optical furnace [2]. The bursting of these bubbles results in the formation of graphene-like structures and nano-petal structures. The stepwise transformation of bubbles of appropriate chemical composition leads to nanotube formation because of their upwards pulling by heated gases. Fullerene-like particles can also have complicated “fish-eye” (“core shell”) structure as a result of the segregation of the transparent BN shell with the H<sub>3</sub>BO<sub>3</sub> layer on the surface around crystalline InN. Nanopowders prepared in an optical furnace under concentrated light heating have complicated gradient or layered structures. According Raman, AES and FTIR studies, the surface of all powders is composed of BN. XRD disclosed pure amorphous boron inside the particles. Gradient transformation of pure boron to BN in the framework of one particle, as well as a layered nanostructure, was observed by the TEM study. References: 1. Frolov, A. A., Sartinska, L. L., Kovala A, Y. & Danilenko, N. A. Application of the optical furnace for nanosized boron nitride production. Nanomaterials 2, 4 (2008). 2. Sartinska, L. L. Catalyst-free synthesis of nanotubes and whiskers in an optical furnace and a gaseous model for their formation and growth. Acta Mater. 59, 4395-4403 (2011). |
