The objective of this project is to develop new materials using synergistic routes for the synthesis and characterization of two-dimensional (2D) nanomaterial encapsulated energetic salts (Thrust one) and cocrystals (Thrust two) formed with eco-oxidizers. These thrusts are complementary and will be developed synergistically. Upon conclusion of this project, materials will be down-selected to transition into a full SERDP program focused on formulations and small scale rocket motor testing. Thrust one will focus on coating energetic salts with 2D nanomaterials to improve the thermal stability, reduce hygroscopicity, and light sensitivity. Thrust two will focus on crystal engineering as an approach to develop novel “specialty” energetics. Specifically, crystal engineering will be used to tailor physical properties such as thermal stability, oxygen balance, and melting point as well as decrease sensitivity. These properties will be investigated by examining energetic cocrystal systems formed from eco-friendly oxidizers and hydrogen-bonding molecules. Collectively, the long-term objective of this project is to develop environmentally-friendly propellants that can replace their toxic counterparts in propulsion and other military applications.

During this limited-scope effort, the Naval Air Warfare Center Weapons Division (NAWCWD) China Lake will create innovative strategies to eliminate or reduce the use of ammonium perchlorate from solid propellants by synthesizing specialty nanocomposite energetics. The efforts will focus on developing a strategy to coat energetic salts, and the synthesis of novel energetic cocrystals, which will lead to improved properties such as reduced hygroscopicity, light sensitivity, and increased thermal stability. Once nanocomposite energetics are synthesized/ characterized, formulations will be made and safety testing will be conducted in-house at NAWCWD. Once the safety data is obtained, the team will determine the compatibility of these specialty energetics with chemicals used in formulations and develop routes toward scale up. Additional testing will include an initial toxicology study of the 2D nanomaterials and oxidizers, which will be investigated by the Army Public Health Center using Quantitative Structure-Activity Relationship models.

The development of a new class of green nanocomposite energetic materials is of broad interest to various industries and sectors. The benefits to the Department of Defense (DoD) and scientific community at large are several fold: a) DoD rocket manufacturing facilities, training grounds, military installations and non-military installations would benefit from the reduced use of ammonium perchlorate, cyclotrimethylenetrinitramine, and implementation of non-toxic green alternative oxidizers, b) alternative non-chlorinated formulations that meet current requirements and performance metrics, c) improved tactical performance of rockets that are smokeless or can be tailored to  produce minimum smoke, d) improved safety and reduced health impact for DoD personnel at airfields/depots/training grounds, e) reduced corrosion of military weapons  and systems and f) reduced ground water contamination.