Probing the Reaction Dynamics of Energetic Materials: The Influence of Physical Properties and Heat Transfer on Ignition and Combustion Characteristics
- Wang, Yujie
- Advisor(s): Zachariah, Michael R
Abstract
Energetic materials convert chemically stored potential energy to kinetic energy through combustion. A current focus within this field is to address the constraints related to mass transfer, which hinder the rapid release of energy from solid-state energetic materials. Nanomaterials have emerged as a promising avenue for overcoming these limitations by reducing the distance between fuels and oxidizers, thereby increasing energy release rates. This dissertation focuses on understanding reaction mechanisms and combustion behavior of solid nanoenergetic composite materials by tuning chemical and physical properties of the components as well as manipulating heat transfer of the composites. Specifically, it sheds light on the crucial role of oxidizer physical properties in influencing the ignition behavior of nanoscale boron, as well as the dominant effect of physical properties of fuels and their corresponding oxides on the microscopic combustion characteristics of composites containing different fuels. A significant portion of this dissertation focuses on tuning the energy release rate of nanoenergetic composites by manipulating heat transfer through various approaches, including: a) Altering the equivalence ratio between fuel and oxidizer, b) Decreasing agglomerate surface tension using an additive, and c) Incorporating carbon fiber to intercept and retain hot agglomerates near the burning surface. These approaches share a common objective of controlling the residence time of agglomerates on or near the burning surface, with longer residence times resulting in increased heat feedback and, consequently, higher energy release rates. Additionally, this dissertation explores the development of energetic biocidal agents using a series of metal iodates by studying their decomposition mechanisms and combustion behavior of assembled composites with nanoscale aluminum as the fuel.