Ionic Cocrystals with Lamellar Architecture to Rationally Tune Materials Properties
Abstract
Reliable solid propellants are required in both civilian and defense sectors. State-of-the-art technology relies on ammonium perchlo,rate (AP) as the solid oxidizer. While delivering on performance AP presents both ecological and tactical challenges as its use rele,ases the toxic perchlorate ion and results in a detectable, HCl-rich plume signature. Ammonium dinitramide (ADN) is a promising oxid,ant, which fully converts to neutral gaseous species (O2, N2, H2O, NOX) thus redressing the shortcomings of AP. ADN, however, is yet, to see broad application due to hygroscopicity and processability challenges (non-ideal crystal morphology). Though chemical altera,tion of ADN is difficult to envisage as an approach to overcome such problems, cocrystal formation offers a promising route. We have, previously developed an ionic cocrystal (crystal containing salt and neutral compounds), ADN-PDO, which exhibits decreased hygrosco,picity, a desirable morphology, and has a balanced oxidant/fuel ratio. Additionally, ADN-PDO has a distinct layering motif (lamellar, architecture) of sheets of salt and neutral component connected via hydrogen bonding interactions.The lamellar architecture observe,d for ADN-PDO has also been observed for non-energetic ionic cocrystals for the first time, resulting in multiple stoichiometries of, the same two components, while preserving the packing of each layer. The discovery of ionic salts with lamellar architecture and th,e resulting impact on properties is the focus of this grant. Initially, the fundamentals of lamellar architecture formation in non-e,nergetic systems will be explored, and the learnings will be applied to create new energetic materials. Characterization of energeti,c properties will allow an understanding of how changes in stoichiometry impact energetic properties. The work contributes to the pr,oduction of more environmentally palatable formulations for producing high performance propellants for military and civilian applica,tions. Approved for Public Release
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jan 14, 2022
- Source ID
- N000142212101
Entities
People
- Adam J. Matzger
Organizations
- Board of Regents of the University of Michigan
- Office of Naval Research
- United States Navy