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

Abstract

In this study, a hypergolic linker (dicyanamide, DCA) and a highenergy nitrogen-rich ligand (1,5-diaminotetrazole, DAT) were applied to construct high-energy metal−organic frameworks (HEMOFs) with hypergolic property. Three novel metal−organic frameworks (MOFs) were synthesized via a mild method with fascinating 2D polymeric architectures, and they could ignite spontaneously upon contact with white fuming nitric acid (WFNA). The gravimetric energy densities of the three HEMOFs all exceeded 26.2 kJ•g −1 . The cupric MOF exhibits the highest gravimetric and volumetric energy density of 27.5 kJ•g −1 and 51.3 kJ•cm −3 , respectively. By adjusting the metal cations, high-energy ligands and hypergolic linkers can improve the performance of hypergolic MOFs. This work provides a strategy for manufacturing MOFs as potential high-energy hypergolic fuels.

“All-in-one” hypergolic metal–organic frameworks with high energy density and short ignition delay

“…Among them, Cu-CTB-EIm displayed the shortest ID of 10 ms, which is comparable to that of famous hydrazine-based fuel unsymmetrical dimethylhydrazine (UDMH), 24 and other reported MOF fuels. 15,16 It is worth noting that substituent groups in the MOF structure have crucial effect on their combustion behavior, where the ID time increased in the following order: Cu-CTB-EIm < Cu-CTB-MIm < Cu-CTB-AIm < Cu-CTB-VIm. This trend is consistent with that of the electrondonating ability of 1-ethyl > methyl >1-allyl > 1-vinyl, implying that simple modication of the MOF structure could achieve the materials with tailored hypergolic properties.…”

“…3,4 However, the intrinsic carcinogenic nature impedes their long-term use. 5 Over the past few years, various materials have been developed as potential hypergolic fuels, such as ionic liquids, 6-10 organic compounds, 11,12 cocrystals, 13 metal complexes, 14 metal-organic frameworks (MOFs) [15][16][17] etc. Among them, MOFs constituted by inorganic metal nodes and organic building blocks featuring a tunable structure and ease of functionalization, have particular potential for shedding light onto developing next generation hypergolic fuels.…”

Biomass Waste Carbonization in Piranha Solution: A Route to Hypergolic Carbons?

“…Hypergolic fuels are mainly used as propellants in rocket engines and simply consist of a fuel and a strong oxidizer that ignite spontaneously upon contact at ambient conditions without external stimuli. Fuels include hydrazine derivatives, heterocyclics, long-chain aliphatics, N-alkyl diamines, aromatics, sugars, ionic liquids, metal-organic frameworks and metal powders (Al, Mg), whereas strong oxidizers include fuming nitric acid HNO 3 , N 2 O 4 , NH 4 ClO 4 , KClO 3 , concentrated H 2 O 2 and Na 2 O 2 to name a few [34][35][36][37][38][39][40][41][42][43][44][45][46]. Some criteria for hypergolic fuels are high energy value (25-50 kJ•g −1 [41]), high density (e.g., preferably solid fuels that occupy less space), inexpensiveness, low toxicity and fast ignition upon contact with a strong oxidizer.…”

Hunting for Energetic Complexes as Hypergolic Promoters for Green Propellants Using Hydrogen Peroxide as Oxidizer

“…Energetic materials, including explosives, propellants, and pyrotechnics, are widely used in both civilian and military applications due to their huge chemical potential energy. − With the development of science and technology, increasing requirements have been placed on energetic materials, for example, high energy density, low sensitivity, light sensitivity, and hypergolicity. − Hypergolic compounds are energetic materials that ignite spontaneously, which gives them important applications in the aerospace industry for simple and repeatable ignition engine systems. , For hypergolic materials, a fast autoignition delay time with an oxidizer is an essential requirement. Today, hydrazine-based compounds, such as monomethyl­hydrazine (MMH) and unsymmetrical dimethylhydrazine (UDMH), are commonly used as hypergolic fuels in liquid bipropellants because of their short ignition delay (ID) time and high specific impulse with the oxidizers of fuming nitric acid (WFNA) and N 2 O 4 ; however, the carcinogenicity and high vapor pressure of the MMH and UNMH restrict their use .…”