High-Energy Metal-Organic Frameworks with a Dicyanamide Linker for Hypergolic Fuels

Area of Science:

• Materials Science
• Chemistry
• Energetic Materials

Background:

• Developing advanced energetic materials is crucial for propulsion and defense applications.
• Metal-organic frameworks (MOFs) offer tunable structures for energy storage and release.
• Hypergolic propellants ignite spontaneously, simplifying ignition systems.

Purpose of the Study:

• To synthesize novel high-energy metal-organic frameworks (HEMOFs) with inherent hypergolic properties.
• To investigate the energy density and ignition characteristics of these new HEMOFs.
• To establish a strategy for designing MOFs as potential hypergolic fuels.

Main Methods:

• Synthesis of three novel MOFs using dicyanamide (DCA) as a hypergolic linker and 1,5-diaminotetrazole (DAT) as a high-energy ligand.
• Characterization of the MOFs' structures, including their 2D polymeric architectures.
• Evaluation of the HEMOFs' hypergolic behavior upon contact with white fuming nitric acid (WFNA).
• Measurement of gravimetric and volumetric energy densities.

Main Results:

• Three new HEMOFs were successfully synthesized using a mild method.
• All synthesized HEMOFs demonstrated spontaneous ignition with WFNA.
• Gravimetric energy densities exceeded 26.2 kJ·g⁻¹ for all HEMOFs.
• The cupric MOF achieved the highest gravimetric (27.5 kJ·g⁻¹) and volumetric (51.3 kJ·cm⁻³) energy densities.

Conclusions:

• The combination of hypergolic linkers and high-energy ligands effectively enhances MOF performance.
• Adjusting metal cations, ligands, and linkers is a viable strategy for improving hypergolic MOFs.
• This research presents a promising pathway for developing MOFs as next-generation hypergolic fuels.