Energetic Ionic Liquids Research Articles

The Crystal Structure of Dodecahedral Ba2+ Hexa-Perchlorate Complex Tetrakis 1-N-Propyl-3-vinyl-imidazol-1-ium·Barium Hexa-Perchlorate

In cold methanol, energetic ionic liquid 1-n-propyl-3-vinyl-imidazol-1-ium perchlorate, 1, crystallizes in the presence of excess Ba(ClO4)2, 2, into tetrakis 1-propyl-3-vinyl-imidazol-1-ium·barium hexa-perchlorate, 3. Crystals of 3, with molecular formula (C8H13N2)4·BaCl6O24, are colorless and monoclinic, with space group P21/c. The crystal structure is characterized by a dodecahedral coordination around the barium atom, with each perchlorate chelating Ba2+ in a κ2O,O’ fashion, and the Ba(ClO4)64− anion is surrounded by four imidazolium cations.

Ultra-fast, Self-destructing technology based on autocatalytic energetic conductive ink

Transient electronics show promising potential in data security and privacy preservation. Key criteria for transient electronic devices include quick production, short lifespan, and irreversible degradation. This article proposes a novel energetic conductive ink (EILs-Fc-SWNTs/EMOFs) with ultra-fast self-destruct performance for information protection. The ink based on carbon nanotubes modified with energetic ionic liquids and combustion rate catalysts, has advantages of high conductivity, high energy properties, and rapid production. Transient electronic devices containing micro-storage chips are achieved through direct writing technology. The writing circuit exhibits excellent conductivity (65.57 S/cm), high flexibility (2000 bending cycles), and high-energy characteristics (1640.3 J/g). The combustion temperature of the printing circuit is estimated at approximately 2100 °C. More importantly, transient electronics device commercial storage chips can be destroyed within 0.9 s.

Vibrational Energy Transfer in Energetic Ionic Liquid 4-Amino-1H-1,2,4-triazolium Nitrate: Ab Initio Molecular Dynamics Simulations.

Energetic ionic liquids (EILs) represent a distinctive class of energetic materials with substantial research significance and promising energetic applications. In this work, we delved into the vibrational energy transfer mechanism within the EILs, specifically focusing on 4-amino-1H-1,2,4-triazolium nitrate (ATN), utilizing ab initio molecular dynamics simulations. Our work illustrates distinct energy transfer patterns for different vibrational modes. Upon exciting the stretching vibration of the NH group in the cationic group, vibrational energy preferentially migrates to the neighboring CH bond within the aromatic ring on the femtosecond to picosecond time scales and notably in an in-phase coherent energy transfer fashion. In contrast, exciting the stretching vibration of the N9H11 bond triggers the transfer of vibrational energy to its neighboring N9H10 bond in an out-of-phase coherent fashion. Conversely, exciting the stretching vibration of the N9H10 bond leads to energy transfer predominantly through intermolecular pathways due to the hydrogen-bonding interaction between this bond and the anion. The vibrational energy of the excited N9H10 stretch is shown to dissipate very rapidly, displaying a fast component (with a time constant as short as ca. 7 fs) and a slow component (ca. 230 fs).

A new equation for determine the degradation temperature in energetic ionic liquid

A new equation for determine the degradation temperature in energetic ionic liquid

“Fireworks” ignition and combustion of metal nanoparticles: Based on the rapid conversion and transmission of microwave energy by energetic ionic liquids

The metal nanoparticles (MNPs) are widely used to improve the output performance of various explosives and propellants, which ignition is an important link for the energy release of fuel. The microwaves have been recognized as a safer and smart ignition method. However, it is difficult to achieve rapid ignition of MNPs under microwave radiation due to the low heating rate. The ADN energetic ionic liquids could efficiently absorb microwaves owing to excellent polarity. This work proposes a method of fast “fireworks” ignition and combustion of MNPs under microwave radiation, by employing ADN as the “central hub” for microwave energy conversion. The dispersion of Al and Ti NPs in ADN endowed the solution with nanofluid properties and significantly improved the thermal conductivity. The solution boiled violently under microwave radiation, causing the temperature of MNPs to rise continuously. Meanwhile, the acidic components produced by ADN pyrolysis destroyed the oxide shell of MNPs, further accelerating the ignition process. The ignition phenomenon of Al and Ti NPs were different due to distinct microwave absorption properties and ignition temperature. When the expanding liquid film broken, the shock wave blew the Al NPs into the air to realize the “fireworks” ignition and combustion. The Ti NPs was ignited in the solution, which further ignited the ADN solution, allowing the system for controllable ignition and combustion. The “fireworks” ignition and combustion performance of MNPs could be modulated by the input microwave power. In summary, the new ignition and combustion method of MNPs will have a profound impact on the design of ignition sequence, the improvement of microwave energy utilization and the expansion of the application of ADN-based liquid propellants.

Replacement of Toxic Hydrazines in Satellite Propulsion with Greener Dinitramide-Based Energetic Ionic Liquid Candidates.

Satellite propulsion uses liquid mono or bi-propellants composed of a hydrazine in combination with a strong oxidant. However, hydrazines are highly toxic. As a result, many research efforts for more environmentally compatible propellants have been made over the past decade. In this study we evidence green formulations that retain high propulsive performances. They are based on the dinitramide anion. From an initial library of 37 ammonium dinitramides 3 best candidates were selected after evaluation of their potential syntheses, calculated theoretical performances, experimental synthesis optimizations and decomposition temperatures. These three salts were then formulated to obtain acceptable sensitivities and melting points, which eventually led to only one formulation being retained: a 40 : 60 mixture of dimethylammonium dinitramide and ammonium dinitramide phlegmatized by 10 % of glycerol.

A comprehensive investigation of 1,3-dibutylimidazolium nitrate ionic liquid as a green energetic oxidizer: From design to thermal stability assessment

The present work introduces a novel energetic ionic liquid (EIL), the 1,3-dibutyl-imidazolium nitrate [BBIm][NO3], that demonstrates interesting features such as symmetrical cation’s structure [BBIm] and the presence of nitrate anion [NO3], which confers the explosophoric oxidizing character. This EIL was synthesized by a simple green method and its chemical structure was fully characterized by 1-D 1H, 13C, 15N NMR, 2-D NMR, and FTIR spectroscopy. Besides, DSC and non-isothermal TGA analyses demonstrated that the [BBIm][NO3] displayed two stages of exothermicity and good thermal stability at temperatures ≤230 °C, which reduced its thermal hazard and enhanced its safe handling. Furthermore, the non-isothermal TGA data combined with isoconversional kinetic methods, i.e., TAS, it-KAS, and Vyazovkin/CE were used to determine the kinetics of its thermal decomposition. The obtained results revealed that the prepared [BBIm][NO3] EIL presents promising reactivity features, which may promote its further use in practical applications.

Multiplexed Electrospray Emission of Green Energetic Ionic Liquids from Wedge-Shaped Porous Emitters

Multiplexed Electrospray Emission of Green Energetic Ionic Liquids from Wedge-Shaped Porous Emitters

Flexible conductive energetic film based on energetic ionic liquids and carbon nanotubes for information security transient electronics

Transient electronics is an emerging class of functional electronics designed to address problems such as potential data leakage and information theft. In order to meet the unification of transient technology and electronics, we prepared a flexible conductive energetic film by assembling energetic ionic liquids (EILs) loaded single-walled carbon nanotubes (SWNTs) and CuO functionalized multi-walled carbon nanotubes (MWNTs). It was found that the interaction between EILs and SWNTs maintains the high conductivity of SWNTs and strengthens the flexibility of the film. The introduce of CuO functional MWNTs enhance the detonation performance of the films by catalyzing EILs combustion. Therefore, obtained flexible conductive energetic film has good conductivity (63.67 S/cm), high energy release (8037 kJ/kg), and high flexibility (1000 bends). It is confirmed that flexible conductive energetic film can meet the requirement of low-voltage operation and high-voltage self-destruction by replacing traditional circuit in an electronic device. The prepared transient chip is able to ignited in 10 ms and completely self-destruct within 0.7 s.

First Example of 1,2,5-Oxadiazole-Based Hypergolic Ionic Liquids: a New Class of Potential Energetic Fuels.

The development of liquid energetic fuels with improved properties is important topic in space propulsion technologies. In this manuscript, a series of energetic ionic liquids incorporating a 1,2,5-oxadiazole ring and nitrate, dicyanamide or dinitramide anion was synthesized and their physicochemical properties were evaluated. The synthesized compounds were fully characterized and were found to have good thermal stabilities (up to 219 °C) and experimental densities (1.21-1.47 g cm-3). Advantageously, 1,2,5-oxadiazole-based ionic liquids have high combined nitrogen-oxygen contents (up to 64.4%), while their detonation velocities are on the level of known explosive TNT, and combustion performance exceeds those of benchmark 2-hydroxyethylhydrazinium nitrate. Considering the established hypergolicity with H2O2 in the presence of a catalyst, and insensitivity to impact, synthesized ionic liquids have strong application potential as energetic fuels for space technologies.

Process hazard assessment of energetic ionic liquid with kinetic evaluation and thermal equilibrium

With the continuous development of battery technology, there are new research investments in materials of various parts. In the field of electrolytes, ionic liquids (IL) are considered to be excellent electrolytes and have been widely studied in distinct energy fields. However, it is necessary to pay attention to the safety characteristics of ionic liquids at high temperature due to the application of energy, but there is little research on the reaction and kinetics of ionic liquids. To ensure the safety of ionic liquids, such as high temperature, the common ionic liquid 1-Ethyl-3-methylimidazolium nitrate ([Emim] NO3) was selected for analysis. The exothermic mode is obtained from the data of differential scanning calorimetry. The basic reaction parameters of [Emim] NO3 were determined with thermodynamic equation simulation. For ionic liquids in the actual situation, consider adding a heat balance model to estimate its temperature change pattern and find out the hazard temperature and related safety parameters. Temperature changes were estimated by constructing 25.0 g and 50.0 g packages to simulate material reactions and heat transfer in the external environment. The results showed that [Emim] NO3 had shorter TMRad and TCL (<1 day) when the temperature was above 180 °C.

ATOMIZATION AND MIXING OF BLENDED ENERGETIC IONIC LIQUID HYDROXYETHYLHYDRAZINIUM NITRATE

Hypergolic propellants are widely used in liquid rocket propulsion. Instantaneous control of combustion, lack of requirement of an ignition system, and storability for long durations are the major advantages of hypergolic propellants. The propellant community is on the lookout for replacements for the currently utilized toxic hydrazine and its derivatives. Energetic hypergolic ionic liquids are excellent candidates for such replacement. However, their high viscosity and surface tension render atomization difficult, and hence, increase the ignition delays in the combustion chamber and reduce combustion efficiency. The current study focuses on the geometrical aspects of injector design and other injection conditions that control the ignition process and combustion efficiency. These mainly depend on the extent of mixing and atomization. Shadowgraphy and patternator-based experiments were performed on doublet and triplet impingement injectors under variable injection conditions, such as impingement angle, jet diameters, and injection velocities. A blend of 50&amp;#37; unsymmetrical dimethylhydrazine in the energetic ionic liquid hydroxyethylhydrazinium nitrate (UHN50) shows promise as a candidate for a hydrazine replacement. A blend of 38&amp;#37; ethanol in glycerol (GE6238) was used as a surrogate for UHN50, whereas water was used as a surrogate for nitrogen tetroxide. The effect of variation of injection conditions was found to be contradictory for achieving atomization and mixing. An optimum criterion was obtained for both atomization and mixing.

Temperature variation measurements of an ignited energetic ionic liquid

Temperature variation measurements of an ignited energetic ionic liquid

Conceptual Design of Small-Sized Thruster Using Laser Ignition of High-Energy Monopropellant

Ammonium dinitramide (ADN)-based energetic ionic liquid propellants (ADN-EILPs) present considerable potential as monopropellants due to high energy density, high thermal/chemical stability, and low toxicity. Consequently, a chemical thruster system based on ADN-EILPs can be employed in the development of high-performance ultrasmall/small satellites. However, the characteristics of the ADN-EILPs present various problems in their ignition during the thruster development. To solve this problem, the authors have previously achieved the continuous-wave (CW) laser ignition of ADN-EILPs using laser absorbers composed of carbon wools. However, the conventional propellant injection of ADN-EILPs with carbon wool using high-pressure gas faces several limitations. Therefore, a propellant feed system suited for the ignition method is proposed here, as well as a conceptual model of a 0.5 U/0.5 N-class thruster operated by the CW laser ignition of ADN-EILPs (). Additionally, an attempt is made to manufacture a laboratory model (LM) thruster, and its fundamental operation properties are determined. The future research implications of this study include the further observation of the combustion of the decomposed gas before its emission from the throat of the LM thruster, along with the further development of the propellant feeding system proposed in this study and the hot-fire tests performed for the feeding systems.

Cover Picture: 4‐Amino‐1‐Butyl‐1,2,4‐Triazolium Dinitramide – Synthesis, Characterization and Combustion of a Low‐Temperature Dinitramide‐Based Energetic Ionic Liquid (EIL) (Prop., Explos., Pyrotech. 7/2022)

The cover image is based on the Research Article 4-Amino-1-Butyl-1,2,4-Triazolium Dinitramide – Synthesis, Characterization and Combustion of a Low-Temperature Dinitramide-Based Energetic Ionic Liquid (EIL) by Uwe Schaller et al. https://doi.org/10.1002/prep.202200054.

4‐Amino‐1‐Butyl‐1,2,4‐Triazolium Dinitramide – Synthesis, Characterization and Combustion of a Low‐Temperature Dinitramide‐Based Energetic Ionic Liquid (EIL)

AbstractSalts being liquid below 100 °C are defined as ionic liquids. Due to their unique properties, they are attracting increasing interest and are also being investigated in the field of energetic materials. Combining nitrogen‐rich cations and oxygen‐rich anions, it is possible to obtain energetic ionic liquids (EILs). Potential applications are plasticizers, high explosives, gun and rocket propellants. However, only few works have been done in the field of EILs which show a glass transition temperature less than −40 °C, the so called low‐temperature EILs (LT‐EILs). LT‐EILs with dinitramide as an anion are an almost unknown group with interesting properties and potential. In this paper we present synthesis, characterization and combustion properties of 4‐amino‐1‐butyl‐1,2,4‐triazolium dinitramide (C4 DN) as a low temperature dinitramide‐based EIL in its entirety for the first time. A classic synthesis route and a metal‐free route are presented. The physical properties were measured and compared to conventional non‐ionic energetic plasticizers like BDNPA/F, TMETN/BTTN, Bu‐NENA and DNDA‐57. The combustion behaviour was studied using an optical window bomb and compared to non‐ionic energetic liquids in use. To evaluate the performance as an energetic plasticizer or additive, the interaction with the energetic binder GAP is investigated by manufacturing of dog bone‐shaped test specimen and comparing their mechanical properties and their glass transition temperatures with conventional energetic plasticizers, based on non‐ionic energetic compounds. As one result, C4 DN showed an intense softening effect. Based on the result, propellant samples were prepared and characterized.

Flexible Conductive Energetic Film Based on Energetic Ionic Liquids and Carbon Nanotubes for Information Security Transient Electronics

Flexible Conductive Energetic Film Based on Energetic Ionic Liquids and Carbon Nanotubes for Information Security Transient Electronics

Synthesis and properties of borane‐containing ionic liquids based on biferrocene

AbstractTo develop a new type of energetic ionic liquid (EIL) that has a catalytic effect on the thermal decomposition of ammonium perchlorate (AP) and can be ignited in white fuming nitric acid (WFNA), six borane‐containing ionic liquids based on biferrocene were successfully synthesized, and their structures were determined by x‐ray crystallography. Except for iodized salts, four EILs with high thermal stability burned rapidly in WFNA, one of which, bis[1‐(ferrocenylmethyl)imidazole‐3‐yl] dihydroboronium cyanoborohydride, [Fcmim][BH3CN], produced the shortest ignition delay (ID) time of 5 ms. However, iodized salts demonstrated a better catalytic effect on AP than did BH3CN−‐ or N(CN)2−‐based EILs and bis[1‐(ferrocenylmethyl)benzimidazole‐3‐yl] dihydroboronium iodide, [Fcbemim][I], could advance the final thermal decomposition temperature of AP by 50°C. Anions have a significant effect on the structures and performances of ionic liquids.

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

The development of hypergolic materials has aroused great interest due to their important applications in aerospace technology. In this work, six new energetic complexes were prepared and comprehensively characterized. All energetic complexes had isostructural characteristics, which made them ideal candidates for studying their structure-performance relationships. These energetic complexes had good thermal stabilities and excellent specific impulses. The vacuum-specific impulses were in the range 264.0-271.9 s, which was greater than most reported solid hypergolic materials. Moreover, the hypergolic performance of these compounds was examined by using 100% HNO3 as the oxidizer, and their catalytic performance in the hypergolic reaction of typical energetic ionic liquids and 90% H2O2 was comprehensively studied. All compounds displayed excellent hypergolic performance with the shortest ignition delay time of 4 ms. The examined copper-containing energetic complexes displayed excellent catalytic activities for the hypergolic reaction between energetic ionic liquids and 90% H2O2. The shortest ignition delay time of the examined hypergolic reactions was 31 ms. The suitable physicochemical properties, excellent energetic properties, and high catalytic activity of the hypergolic reactions have demonstrated the great potential of these energetic complexes as promoters for the development of green hypergolic bipropellants.

Modular Impulsive Green Monopropellant Propulsion System (MIMPS-G): For CubeSats in LEO and to the Moon

Green propellants are currently considered as enabling technology that is revolutionizing the development of high-performance space propulsion, especially for small-sized spacecraft. Modern space missions, either in LEO or interplanetary, require relatively high-thrust and impulsive capabilities to provide better control on the spacecraft, and to overcome the growing challenges, particularly related to overcrowded LEOs, and to modern space application orbital maneuver requirements. Green monopropellants are gaining momentum in the design and development of small and modular liquid propulsion systems, especially for CubeSats, due to their favorable thermophysical properties and relatively high performance when compared to gaseous propellants, and perhaps simpler management when compared to bipropellants. Accordingly, a novel high-thrust modular impulsive green monopropellant propulsion system with a micro electric pump feed cycle is proposed. MIMPS-G500mN is designed to be capable of delivering 0.5 N thrust and offers theoretical total impulse Itot from 850 to 1350 N s per 1U and &gt;3000 N s per 2U depending on the burnt monopropellant, which makes it a candidate for various LEO satellites as well as future Moon missions. Green monopropellant ASCENT (formerly AF-M315E), as well as HAN and ADN-based alternatives (i.e., HNP225 and LMP-103S) were proposed in the preliminary design and system analysis. The article will present state-of-the-art green monopropellants in the (EIL) Energetic Ionic Liquid class and a trade-off study for proposed propellants. System analysis and design of MIMPS-G500mN will be discussed in detail, and the article will conclude with a market survey on small satellites green monopropellant propulsion systems and commercial off-the-shelf thrusters.