Recent developments in the field of energetic ionic liquids

Abstract

Energetic ionic liquids (EILs) are a subset of the rapidly growing field of ionic liquid research.

Synthesis and Physical and Chemical Properties of Hypergolic Chemicals such as N,N,N-Trimethylhydrazinium and 1-Ethyl-4-Methyl-1,2,4-Triazolium Salts

“…The extremely carcinogenic nature of hydrazine as well as its volatility presents difficulties for its handling [1,2,4]. Finding a way to replace hydrazine is one of the main goals of researchers in this field.…”

“…[1]. For military applications, propellants are employed for firing bullets, missiles, and rockets, as well as ejecting pilots [2]. More commonly used high explosives such as RDX (1,3,5-trinitroperhydro-1,3,5-triazine) [3] or TNT (2,4,6-trinitrotoluene) [3] are inappropriate for rocket propellant due to poor performance, high sensitivities, high production costs, and detrimental decomposition gases [4][5][6].…”

“…Furthermore, hypergolic ILs could serve as bipropellant fuels over a variety of conditions due to the high thermal and chemical stabilities, low volatilities, and long liquid ranges [2,15]. A new family of dicyanoborates ILs has been synthesized in water with substituted nacyclic, N-cyclic, and azolium cations to meet the desired criteria required for well-performing fuels [2,15].…”

“…After the first report of a hypergolic ionic liquid (IL) in 2008 [15], researchers have focused on synthesizing hypergolic ILs with low melting points, wide liquid ranges, high thermal stabilities, and short ignition-delay (ID) times [16][17][18][19][20][21][22][23]. Furthermore, hypergolic ILs could serve as bipropellant fuels over a variety of conditions due to the high thermal and chemical stabilities, low volatilities, and long liquid ranges [2,15]. A new family of dicyanoborates ILs has been synthesized in water with substituted nacyclic, N-cyclic, and azolium cations to meet the desired criteria required for well-performing fuels [2,15].…”

Azetidinium‐based Hypergolic Ionic Liquids with High Strain Energy

“…[7] This provided an opportunity to replace the toxic hydrazine derivatives with green bipropellant fuels. Since then, attentions have been increasingly paid to ILs due to their characteristics, such as negligible vapor pressure, high thermal stability, low toxicity, [2,[8][9][10] Currently, many studies focus on the design of ILs with good hypergolicity and fluidity, including cations such as alkyl-substituted imidazolium, triazolium, pyrrolidinium, pyridinium, [11,12] and anions such as N(CN) 2 À , [13] BH 4 À , [14,15] BH 3 CN À , [16][17][18] BH 2 (CN) 2 À , [19] N 3 À , [20][21][22] …”