A study on boron nitride nanomaterials and their nanocomposites for electrical magnetic and surface properties

Abstract

Boron Nitride (BN) is a ceramic material capable of withstanding very high temperatures and has a very high bandgap. It is a polymorphic compound made of boron and nitrogen. It exists in several different crystal structures namely amorphous BN, hexagonal BN (hBN) and cubic BN among others. Here the research work focuses on the varied applications in which BN plays a major role. Boron Nitride Nanotubes (BNNTs) are the center of attention in this research work. BNNTs are rolled-up variations of hBN. They are highly crystalline akin to carbon nanotubes (CNTs) but offer better thermal conductivity than CNTs. They are used in medical applications, nanocomposites and neutron shields to name a few. They can be dispersed easily in a polymer matrix than CNTs, this property is quite rare in nanomaterials. Here, hBN in both particulate form and nanotube form were used to fabricate nanocomposites. This research thesis is divided into three sections, each section containing separate works using BN nanomaterials. 1. BNNT synthesis and ferromagnetism in BNNTs BNNTs were synthesized by chemical vapor deposition technique (CVD) at 1150 °C. The CVD technique is very simple and it offers high yield and high purity compared to other techniques such as laser ablation and arc discharge. Elemental amorphous boron and nickel oxide were the two solid precursors used. The synthesis was carried out in a tubular furnace, with the reactants carefully mixed in weight ratios and placed inside. newline