While carbon/carbon composites (C/C) have found broad use in commercial aircraft brakes, their further application is limited by high fabrication costs, susceptibility to oxidation, and high electrical conductivity. Boron nitride (BN) provides a suitable alternative to carbon because of its oxidation resistance and its low dielectric constant. This thesis describes a novel approach to the synthesis of BN composites and films based on borazine, the boron-nitrogen analog of benzene. Characteristics of the oligomer are described and a more optimum processing route to the BN structures is proposed. Specifically, it is shown that the treatment of the oligomer in the melt phase can enhance the crystallinity of the final BN. The stability, electrical properties, wear, and mechanical behavior of BN matrix composites are then presented. The substitution of a BN matrix in place of a carbon matrix is shown to enhance the oxidation stability, improve the wear resistance, and offer the potential for a low dielectric, thermally stable composite. Finally, the feasibility of either dip or spin coating thin BN films is demonstrated and parameters controlling the thickness and dielectric constant in the films are described.

Hexagonal Boron Nitride: Synthesis, Properties, and Applications offers a comprehensive approach to hexagonal boron nitride (h-BN), covering synthesis, exfoliation, properties, characterization, functionalization, heterostructures, nanocomposites, and modelling and simulation, and guiding the reader towards advanced applications in biomedicine, electronics, energy storage, wastewater treatment, and other areas.The book begins by introducing hexagonal boron nitride, discussing classification, structure, synthesis methods, exfoliation, and functionalization techniques. This is followed by in-depth coverage of properties and characterization, as well as heterostructures and other two-dimensional materials, as well as nanocomposites. The fourth section of the book examines specific target applications, covering a range of cutting-edge areas including micro- and nano-electronics, anti-friction and anti-corrosive coatings, bone tissue engineering, wound healing, nanomedicine, drug delivery, catalysis, water treatment, energy storage and conversion, sensing and bio-sensing, and fire-retardant applications. Finally, computational modelling and simulation, and environmental aspects, are addressed in detail.This is a valuable resource for researchers and advanced students across nanotechnology, materials science, chemistry, environmental science, chemical engineering, biomedicine, electronics, and engineering. In an industrial setting, this book supports scientists, engineers, and R&D professionals with an interest in advanced 2D materials or nanomaterials for advanced applications. Presents the synthesis, properties, functionalization, and characterization methods for hexagonal boron nitride Explores novel applications across biomedicine, electronics, energy storage, and water treatment Addresses key challenges, such as biocompatibility, toxicity, and environmental and health impact

Boron nitride was first produced in the 18th century and, by virtue of its extraordinary mechanical strength, has found extensive application in industrial processes since the 1940s. However, the more recent discovery that boron nitride allotropes are as structurally diverse as those of carbon (e.g. fullerenes, graphene, carbon nanotubes) has placed this material, and particularly its low-dimensional allotropes, back at the forefront of modern material science. This book provides a comprehensive history of this rapid rise in the status of boron nitride and boron nitride nanomaterials, spanning the earliest examples of three-dimensional boron nitride allotropes, through to contemporary structures such as monolayer hexagonal boron nitride, boron nitride nanomeshes, boron nitride nanotubes and the incorporation of boron nitride into cutting-edge van der Waals heterostructures. It specifically focuses on the properties, applications and synthesis techniques for each of these allotropes and examines how the evolution in boron nitride production methods is linked to that in our understanding of how low-dimensional nanomaterials self-assemble, or ‘grow’, during synthesis. The book demonstrates the key synergy between growth mechanisms and the development of new, advanced nanostructured materials.

This thesis focuses on the growth of a new type of two-dimensional (2D) material known as hexagonal boron nitride (h-BN) using chemical vapor deposition (CVD). It also presents several significant breakthroughs in the authors’ understanding of the growth mechanism and development of new growth techniques, which are now well known in the field. Of particular importance is the pioneering work showing experimental proof that 2D crystals of h-BN can indeed be hexagonal in shape. This came as a major surprise to many working in the 2D field, as it had been generally assumed that hexagonal-shaped h-BN was impossible due to energy dynamics. Beyond growth, the thesis also reports on synthesis techniques that are geared toward commercial applications. Large-area aligned growth and up to an eightfold reduction in the cost of h-BN production are demonstrated. At present, all other 2D materials generally use h-BN as their dielectric layer and for encapsulation. As such, this thesis lays the cornerstone for using CVD 2D h-BN for this purpose.

Boron nitride thin films can be deposited on different substrates using techniques such as plasma deposition, ion beam deposition and reactive sputter deposition.