EP4314208A1 - Hypergolic composition - Google Patents

Abstract

The present invention provides kits and compositions for e.g., hypergolic ignition of rocket propellant. The disclosed kits and the compositions comprise inter alia a fuel, a gelling agent, and an ignition agent; wherein the ignition agent is stably dissolved within the fuel.

Description

HYPERGOLIC COMPOSITION

CROSS-REFERENCE TO RELATED APPLICATIONS

[001] This application claims the benefit of priority of U.S. Provisional Patent Application No. 63/165,866, titled “HYPERGOLIC COMPOSITION”, filed March 25, 2021, the content of which are incorporated herein by reference in their entirety.

FIELD OF INVENTION

[001] This invention is directed to, inter alia, to a gelled hypergolic composition comprising an ignition agent dissolved within the fuel.

BACKGROUND OF THE INVENTION

[002] Hypergolic propellants can be used in a wide range of applications due to their advantages, including: simplicity (i.e., eliminating the need for a separate ignition source and being reliable with reduced weight), and safety (i.e., preventing accumulation of unreacted propellant and risk of hard ignition and engine blast).

[003] Fuels, such as monomethyl hydrazine combined with oxidizers, including nitrogen tetroxide, or inhibited red fuming nitric acid, have typically been employed in hypergolic bipropellant systems. However, these propellants are considered as highly toxic and carcinogenic chemicals to humans, making their implementation in propulsion systems expensive and problematic.

[004] In the last decades, there is a growing interest in the use of hydrogen peroxide as an alternative oxidizer due to its properties such as non-toxic (green propellant), non- cryogenic, storable with a high density specific impulse. Several studies have been conducted to investigate the hypergolicity of hydrogen peroxide with different types of fuels.

[005] In nature, hydrogen peroxide and the fuel do not ignite upon contact. By using a gelled fuel, a uniform suspension of reactive compounds or ignition agents that react exothermically with hydrogen peroxide can be achieved. The generated heat enables the fuel to reach its flash point which results in ignition, hence, renders the fuel hypergolic with hydrogen peroxide.

[006] The commonest ignition agents are complexes of transition metal salts composed of high atomic weight atoms (such as manganese, copper and iron) and metal hydrides, respectively. The main drawback of using metal hydrides as an ignition agent, is its poor solubility in the fuel, so that the resulting dispersion of the metal hydride within the fuel is unstable upon prolonged storage, thus causing precipitation of the metal hydride particles.

[007] Accordingly, there is an unmet need for a cost effective, reliable and safe ignition system for liquid propellants, which is substantially devoid of particulate matter upon prolonged storage, especially at low temperatures.

SUMMARY OF THE INVENTION

[008] This invention is directed to, inter alia, to a composition comprising an energetic fuel additive and an ignition agent. The composition can ignite hypergolically (i.e., upon contact) with an oxidizer.

[009] In one aspect of the invention, there is a composition comprising an oxidizer and a fuel; wherein said fuel comprises an ignition agent dissolved within the fuel and a gelling agent; said gelling agent is at a concentration ranging from 2% to 8%, by total weight of said fuel.

[010] In one embodiment, the ignition agent comprises a metal hydride.

[Oil] In one embodiment, the metal hydride is selected from the group consisting of: sodium borohydride, lithium aluminum hydride, and a combination thereof.

[012] In one embodiment, the fuel comprises a glycol ether.

[013] In one embodiment, the glycol ether comprises any one of a diglyme, a triglyme, a tetraglyme or a combination thereof.

[014] In one embodiment, the oxidizer comprises one or more materials selected from the group consisting of hydrogen peroxide, cerium, chlorite, bromite, fluorite, chlorate, bromate, fluorate, hyporchlorite, oxygen, nitrous oxide, nitrous acid, nitric acid, and perchloric acid including any salt or any combination thereof.

[015] In one embodiment, the oxidizer comprises hydrogen peroxide.

[016] In one embodiment, wherein (i) said oxidizer, (ii) said fuel or both, is in a form of a liquid or a gel.

[017] In one embodiment, the composition is a hypergolic propellant combination. [018] In one embodiment, the gelling agent comprises one or more materials selected from the group consisting of: a nano- silica fumed powder, aluminum stearate, Carbopol, paraffin, and methocel. [019] In one embodiment, the ignition agent is at a concentration ranging from 4% to 10%, by total weight of said fuel.

[020] In one embodiment, a weight per weight (w/w) ratio between said fuel and said oxidizer within said composition is between 1:3 and 1:5.

[021] In one embodiment, the composition is characterized by a viscosity ranging from 10³-10⁵ Pa*s.

[022] In one embodiment, the composition is characterized by ignition delay time of up to 10ms.

[023] In another aspect, there is a kit of parts comprising (a) a first container comprising the fuel of the invention; and (b) a second container comprising the oxidizer of the invention.

[024] In one embodiment, the fuel is substantially devoid of a particulate matter upon storage at temperature ranging from -40 to +60°C.

[025] In one embodiment, a w/w ratio between the oxidizer and the fuel within said kit is between 5 : 1 and 3:1.

[026] In one embodiment, the kit further comprises a means for contacting said fuel and said particle from the first container with said oxidizer from the second container. [027] In one embodiment, the means comprises a chamber and/or a suction channel. [028] In one embodiment, the chamber is a combustion chamber.

[029] In one embodiment, the suction channel is a pressurized system and/or an injection system.

[030] In another aspect, there is a method for obtaining a hypergolic composition , the method comprising the following steps: providing the kit of the invention; and mixing a predetermined amount of said oxidizer and said fuel, thereby obtaining said hypergolic composition.

[031] In one embodiment, the predetermined amount comprises a w/w ratio of said fuel to said oxidizer being between 1:3 and 1:5.

[032] Unless otherwise defined, all technical and/or scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the invention pertains. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of embodiments of the invention, exemplary methods and/or materials are described below. In case of conflict, the patent specification, including definitions, will control. In addition, the materials, methods, and examples are illustrative only and are not intended to be necessarily limiting. BRIEF DESCRIPTION OF THE DRAWINGS

[033] Some embodiments of the invention are herein described, by way of example only, with reference to the accompanying drawings. With specific reference now to the drawings in detail, it is stressed that the particulars shown are by way of example and for purposes of illustrative discussion of embodiments of the invention. In this regard, the description taken with the drawings makes apparent to those skilled in the art how embodiments of the invention may be practiced.

[034] FIGs. 1A-C are micrographs showing various degree of crystallization in (1A) triglyme solution containing 10% (wt.%) of NaBPE; (IB) triglyme solution containing 10% (wt.%) of NaBtE and 3% (wt.%) of fumed silica; (1C) triglyme solution containing 10% (wt.%) of NaBPE and 5% (wt.%) of fumed silica. The tested compositions were stored at about -25 °C for about 5days.

[035] FIGs. 2A-C are graphs demonstrating Combustion Chamber Pressure (Pc) measured for gelled fuel mixture containing 7% (wt.%) NaBPE, 3% (wt.%) of fumed silica in triglyme, at various for Oxidizer to Fuel Ratios (O/F): 4.3 (2A); 4.0 (2B); 3.3 (2C).

[036] FIG. 3 is a graph presenting the viscosity of gelled fuel mixtures containing 7.5% (wt.%) NaBPE, 3% (wt.%) in triglyme at various concentrations of fumed silica (3 and 5% (wt.%)), versus a similar fuel mixture without the gellant (fumed silica). [037] FIG. 4 is a graph presenting the shear stress of gelled fuel mixtures containing 7.5% (wt.%) NaBPE, 3% (wt.%) in triglyme at various concentrations of fumed silica (3 and 5% (wt.%)), versus a similar fuel mixture without the gellant (fumed silica).

DETAILED DESCRIPTION OF THE INVENTION [038] The present invention, in some embodiments thereof, relates to a composition comprising an ignition agent dissolved within the fuel, and wherein the fuel is gelated by a gelling agent.

[039] The disclosed composition, in an embodiment thereof, is a hypergolic composition, e.g., capable of igniting spontaneously a fuel source. In another embodiment, a hypergolic composition comprising the ignition agent dissolved within the fuel is utilized for a propellant e.g., a rocket propellant.

[040] Before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not necessarily limited in its application to the details set forth in the following description or exemplified by the Examples. The invention is capable of other embodiments or of being practiced or carried out in various ways. [041] According to an aspect of some embodiments of the present invention, there is provided a composition comprising an oxidizer and a fuel; wherein: said fuel comprises an ignition agent dissolved within the fuel and a gelling agent; said gelling agent is at a concentration ranging from 2% to 8%, by total weight of said fuel. In some embodiments, the fuel is a gelled fuel. In some embodiments, the composition of the invention is a hypergolic propellant combination or a hypergolic propellant composition.

[042] In some embodiments, the fuel can ignite hypergolically (i.e. upon contact) with an oxidizer. The fuel and the oxidizer may be chosen from a wide spectrum of materials. In some embodiments, the fuel and/or the oxidizer are environmentally friendly (green propellants) without the need of carrying a protective equipment. These propellants may provide the necessary energy for propulsion.

[043] In another aspect, there is provided a composition comprising a fuel (e.g., a rocket propellant), an ignition agent and a gelling agent, wherein the gelling agent is at a concentration ranging from 2% to 8%, by total weight of said fuel, wherein the fuel is a gelled fuel; and wherein the composition is substantially devoid of a particulate matter of the ignition agent. In some embodiments, the composition of the invention being substantially devoid of a particulate matter of the ignition agent is also referred to herein as a “stable composition”.

[044] In some embodiments, the composition of the invention is in a form of a gel. In some embodiments, the composition of the invention is stable upon storage at a temperature ranging from -40 to +60°C, -40 to -20°C, -20 to -10°C, -10 to 0°C, 0 to 20°C, 0 to +60°C, including any range between. In some embodiments, the composition of the invention is substantially devoid of a particulate matter upon storage at temperature ranging from -40 to +60°C upon storage.

[045] In some embodiments, storage is referred to a time interval of between 1 week and 20 years (y), between 1 week and 1 y, between 1 y and 2 y, between 2y and 5 y, between 5 y and 10 y, between lOy and 20 y, including any range between.

[046] In some embodiments, the stable composition is substantially devoid of a particulate matter of the ignition agent, wherein substantially comprises a particulate matter of the ignition agent being less than 10%, less than 5%, less than 1%, less than 0.1%, less than 0.01%, less than 0.001%, less than 0.00001% by weight of the ignition agent within the composition. In some embodiments, particulate matter refers to solid particles of the ignition agent with a particle size between lOnm and IOOmhi, between lOnm and lOOnm, between lOOnm and 500 nm, between 500nm and 1 mih, between 1 mih and 5mhi, between 5mhi and IOmhi, between IOmhi and 50mhi, between 50mhi and IOmhi, between 1 mih and 100mm, between 1 mih and 10mm, including any range between.

[047] In some embodiments, particulate matter refers to solid particles (e.g., crystals) of the ignition agent with a particle size of at least 500nm, at least 1 um, at least 5 um, at least 10 um, at least 50um, at least 3um, at least 20um, at least 30um, including any range between.

[048] In some embodiments, the particle size is an average particle size.

[049] As noted hereinabove, the stability of the ignition agent solution within the fuel is increased by adding a gelling agent thereto. In some embodiments, a weight per weight (w/w) concentration of the gelling agent within the fuel ranges from 2% to 8%, so as to result in a semi-liquid or a gelled fuel composition of the invention. Without being bound by any particular theory and mechanism, the gelling agent stabilizes the solution and thus reduces the formation of solid precipitants, especially upon prolonged storage under extreme conditions.

[050] In some embodiments, the ignition agent comprises one or more materials selected from a transition metal or a composition thereof, an alkali metal, a metal hydride, a metal salt, and an alkyl-substituted amine.

[051] In some embodiments, the transition metals are selected from manganese (Mn), cobalt (Co), magnesium (Mg), vanadium (V), silver (Ag) chromium (Cr) platinum (Pt), ruthenium (Ru), palladium (Pd), iron (Fe), nickel (Ni) and copper (Cu).

[052] A non-limiting exemplary composition of transition metal is MnC . In some embodiments, the metal hydrides are selected from, but not limited to, sodium hydride, sodium borohydride, aluminum hydride, lithium aluminum hydride, lithium borohydride, potassium borohydride, copper hydride, beryllium hydride, magnesium hydride, and any combination thereof.

[053] In some embodiments, the ignition agent is selected so as to provide a hypergolic reaction with the oxidizer. Alternatively, the ignition agent is a catalyst which induces the reaction between the fuel and the oxidizer. [054] In some embodiments, the ignition agent comprises a complex of an alkyl- substituted amine and a metal salt. In some embodiments, the alkyl-substituted amine is selected from the group consisting of an alkyl-substituted diamine and an alkyl- substituted triamine and the metal salt is the metal salt of an aliphatic carboxylic acid. In some embodiments, the aliphatic carboxylic acid is selected from the group consisting of an acetate, a propionate and a butyrate.

[055] In some embodiments, the ignition agent reacts upon contact with an oxidizer to produce an exothermic reaction. Alternatively or additionally, the ignition agent comprises a hypergolic catalyst.

[056] In some embodiments, the ignition agent of the invention comprises a metal hydride (e.g. NaH, AIH3). In some embodiments, the ignition agent of the invention is or comprises a metal borohydride. In some embodiments, the metal borohydride is selected from the group consisting of sodium borohydride, lithium borohydride, lithium aluminum hydride, and potassium borohydride. In some embodiments, the metal hydride comprises an organoaluminium hydride (e.g. Diisobutylaluminium hydride, DIBAL).

[057] In some embodiments, the ignition agent of the invention is or comprises sodium borohydride.

[058] In some embodiments, the composition of the invention comprises the ignition agent dissolved in the fuel (e.g., in the continuous phase of the composition of the invention). In some embodiments, the composition of the invention comprises the ignition agent dissolved in the gelled fuel.

[059] In some embodiments, at least 90%, at least 91%, at least 92%, at least 93%, at least 95%, at least 97%, at least 98%, at least 99%, at least 99.1%, at least 99.9% by weight of the ignition agent is stably dissolved within the fuel, including any range between.

[060] In some embodiments, the composition of the invention is or comprises the solution of the ignition agent within the gelled fuel.

[061] In some embodiments, the composition of the invention is stable (e.g., devoid of precipitation and/or formation of any particulate matter, wherein particulate matter is as described herein), upon storage for a time period ranging between 1 week and 20 years (y), between 1 week and 1 y, between 1 y and 2 y, between 2y and 5 y, between 5 y and 10 y, between lOy and 20 y, including any range between. [062] In some embodiments, the stable composition is substantially devoid of precipitation and/or a particulate matter therewithin, wherein particulate matter refers to solid particles having a size between lOnm and IOOmhi.

[063] In some embodiments, the stable composition comprises less than 5%, less than 4%, less than 3%, less than 1%, less than 0.5%, less than 0.1% of the particulate matter of the ignition agent by total weight thereof, including any range between.

[064] In some embodiments, the concentration of the ignition agent (e.g., sodium borohydride) within the composition of the invention is between 4 and 10%, between 1 and 2%, between 2 and 4%, between 4 and 6%, between 4 and 8%, between 6 and 8%, between 6 and 10%, between 8 and 10% (wt.%), including any range between. [065] In some embodiments, the maximum concentration of the ignition agent (e.g., sodium borohydride) within the composition of the invention is predetermined by the solubility thereof within the fuel. In some embodiments, the concentration of the ignition agent is the upper solubility limit of the ignition agent within the fuel.

[066] In some embodiments, the concentration of the ignition agent (e.g., sodium borohydride) within the composition of the invention is (e.g., sodium borohydride) is less than 10% (wt.%), less than 9% (wt.%), less than 8% (wt.%), less than 7% (wt.%), including any range between.

[067] Unless stated otherwise by "wt.%" or "% wt." it is meant to refer to relative to the total weight of the composition (excluding the oxidizer if exists).

[068] In some embodiments, the fuel within the composition of the invention is capable of dissolving the ignition agent. In some embodiments, the fuel is capable of dissolving the ignition agent up to a concentration of about 10% (wt.%), about 9% (wt.%), about 8% (wt.%), about 7% (wt.%), about 6% (wt.%), of the ignition agent within the fuel, including any range between.

[069] In some embodiments, the fuel is or comprises an ether (e.g., a cyclic or a linear ether, such as tetrahydrofuran, oxirane, furan). In some embodiments, the fuel is or comprises a glycol (e.g. ethylene glycol, propylene glycol). In some embodiments, the fuel is or comprises a polyalkylene glycol, or a polyether. In some embodiments, the fuel is or comprises a glycol ether.

[070] In some embodiments, the fuel is represented by Formula: R-0-(CH₂-CH₂-0)n- R, wherein R is H or a Cl -Cl 8 alkyl, and n is an integer ranging between 1 and 20, between 1 and 3, between 3 and 5, between 5 and 10, between 10 and 15, between 15 and 20, including any range between.

[071] In some embodiments, the fuel is or comprises at least one of diglyme, triglyme tetraglyme, pentaglyme, or a combination thereof.

[072] In some embodiments, the fuel is or comprises triglyme, tetraglyme or both. [073] In some embodiments, the composition of the invention is substantially homogenous. In some embodiments, the composition further comprises a fuel. In some embodiments, the composition further comprises an oxidizer. In some embodiments, the oxidizer is in the form of a liquid or a gel. In some embodiments, the particle is suspended in the fuel. In some embodiments, the composition is a hypergolic propellant combination. A hypergolic propellant combination is one where the propellants spontaneously ignite when they come into contact with each other and may be used e.g., in a rocket engine.

[074] In some embodiments, the oxidizer is in the form of a liquid. In some embodiments, the oxidizer is in the form of a gel. In some embodiments, fuel is in the form of a liquid. In some embodiments, the fuel is in the form of a gel.

[075] The term "gel" used herein refers to a semisolid colloidal suspension of a solid in a liquid. Thus, a gel comprises a continuous phase (also referred to as a continuous liquid phase) and a dispersed phase (e.g., a liquid or solid phase). Exemplary gels include a solid phase dispersed in a liquid phase. In some embodiments, the gel comprises a matrix of cross-linked gelling agent dispersed (e.g., stably dispersed without precipitation or sedimentation, and/or phase separation) within the continuous liquid phase. In some embodiments, the matrix is physically bound to the fuel molecules, thereby increasing viscosity of the gelled fuel, as compared to pristine fuel (e.g., devoid of the gelling agent).

[076] In some embodiments, the gelled fuel is characterized by a viscosity being at least 5 times, at least 20 times at least 100 times, at least 500 times, at least 1000 times, at least 10.000 times, at least 100.000 times greater than the viscosity of the pristine fuel. In some embodiments, the viscosity of the gelled fuel as compared to the viscosity of the pristine fuel is measured at 25°C.

[077] In some embodiments, the composition of the invention (e.g., being in a form of a gel) is characterized by a viscosity being at least 5 times, at least 20 times at least 100 times, at least 500 times, at least 1000 times, at least 10.000 times, at least 100.000 times greater than the viscosity of a similar composition devoid of the gelling agent, when the viscosity is measured at 25°C.

[078] In some embodiments, the composition of the invention is a fluid. In some embodiments, the composition of the invention is a flowable composition. In some embodiments, the composition of the invention is a flowable composition, configured for dispensing thereof via injection. In some embodiments, the composition of the invention is an injectable composition.

[079] In some embodiments, the gel is a shear thinning fluid. As used herein, the term "shear thinning" refers to a property of a fluid, wherein the gel viscosity decreased under increasing shear stress, or even liquefies. In some embodiments, the gel is flowable. In some embodiments, the gel a non-Newtonian fluid.

[080] In some embodiments, the gel is a thixotropic fluid. As used herein, the terms "thixotropic" and "thixotropy" describe a property of a fluid, whereby the gel viscosity is reduced under constant shear stress, even liquifies when disturbed (e.g., agitated, for example, by stirring, by downstream flow), and returns to a semisolid, gel state after the disturbance ceases.

[081] In some embodiments, the composition of the invention is a gel comprising the fuel as the continuous liquid phase, wherein the fuel is gelled by the gelling agent. In some embodiments, the continuous liquid phase comprises a solution of the ignition agent within the fuel. In some embodiments, the continuous liquid phase comprises the ignition agent substantially dissolved within the fuel. In some embodiments, the fuel is a solvent, capable of dissolving the ignition agent at an amount of up to 10%, up to 8% by weight of the fuel, including any range or value between.

[082] In some embodiments, the composition of the invention comprises a gelled fuel comprising the ignition agent (e.g., between 4 and 10% by weight of the fuel). In some embodiments, the ignition agent is dissolved (e.g., uniformly distributed) within the gelled fuel. In some embodiments, the ignition agent is a metal salt being dissolved (e.g., dissociated into an anion and a metal cation) within the fuel or within the gelled fuel. In some embodiments, the ignition agent is substantially in the form of distinct molecules or ions within the composition of the invention, wherein substantially refers to at least 70%, at least 80%, at least 90%, at least 95%, at least 97%, at least 99%, at least 99.%, at least 99.99%, at least 99.999% of the total weigh of the fuel within the composition. [083] In some embodiments, the composition of the invention is a fluid. In some embodiments, the composition of the invention is a flowable composition.

[084] In some embodiments, the oxidizer comprises a gelling agent. In some embodiments, the fuel comprises a gelling agent.

[085] As used herein, the term "gelling agent" describes a compound which may be added to a liquid, wherein upon its addition to the liquid, the resulting composition becomes a gel.

[086] The gelling agent may comprise e.g., an organic or an inorganic compound (e.g., a small molecule, an oxide, a salt, etc.) or a mixture thereof. The gelling agent may comprise a polymeric material.

[087] Non-limiting examples of gelling agents contain but are not limited to metal oxide nanoparticle (e.g., S1O2, T1O2, AI2O3, Fe₂0₃, ZnO, and ZrO or any combination thereof), a long chain fatty acid salt (e.g., aluminum stearate), an acrylate polymer including any salt or ester thereof (e.g., Carbopol), alkylated cellulose (e.g., C1-C10 alkylated cellulose, such as methyl cellulose), paraffin and any combination thereof. [088] In some embodiments, the long chain fatty acid salt comprises a metal salt of a long chain fatty acid, wherein the long chain fatty acid comprises between 10 and 40, between 7 and 40, between 7 and 25, between 10 and 25, between 25 and 40 carbon atoms including any range between.

[089] In some embodiments, the metal salt of the long chain fatty acid comprises any monovalent, divalent, or a trivalent metal cation (e.g., an alkali metal, an earth alkali metal, or a transition metal). In some embodiments, the metal salt of the long chain fatty acid comprises aluminum stearate.

[090] In exemplary embodiments, the gelling agent is or comprises metal oxide nanoparticles, such as comprises silica nanoparticles. In some embodiments, the silica nanoparticles are fumed silica nanoparticles (also referred to herein as nano-silica fumed powder).

[091] In some embodiments, the metal oxide nanoparticles (e.g., silica nanoparticles) a surface are of at least 50 m²/g, at least 80 m²/g, at least 100 m²/g, at least 120 m²/g, at least 150 m²/g, at least 180 m²/g, at least 200 m²/g, or between 100 and 300 m²/g, between 50 and 300 m²/g, between 100 and 200 m²/g, between 200 and 300 m²/g, including any range or value therebetween. [092] In some embodiments, the metal oxide nanoparticles are characterized by a porosity of between 50 and 92%, between 50 and 70%, between 70 and 90%, between 70 and 93%, between 70 and 95%, including any range or value therebetween.

[093] In some embodiments, the w/w concentration of the gelling agent within the fuel (e.g., nano-silica fumed powder) is between 2% and 8%, between 1% and 10%, between 0.5% and 8%, between 1% and 2%, between 2% and 4%, between 4% and 8%, between 4% and 6%, between 6% and 8%, between 8% and 10%, including any value or range therebetween.

[094] In exemplary embodiments, the w/w concentration of the gelling agent (e.g., nano- silica fumed powder) within the fuel is between 3% and 5%.

[095] In some embodiments, the size of the particle described herein represents an average size of a plurality of nanoparticles of the nano-silica fumed powder or an aggregate thereof.

[096] In some embodiments, the average size (e.g., diameter, length) of the aggregate ranges from about 1 nanometer to 500 nanometers. In some embodiments, the average size ranges from about 100 nanometer to about 400 nanometers. In some embodiments, the average size ranges from about 200 nanometer to about 300 nanometers.

[097] In some embodiments, the average size is about 50 nm, about 60 nm, about 70nm, about 80 nm, about 90 nm, about 100 nm, about 110 nm, about 120 nm, about 130 nm, about 140 nm, about 150 nm, about 160 nm, about 170 nm, about 180 nm, about 190 nm, about 200 nm, about 210 nm, about 220 nm, about 230 nm, about 240 nm, about 250 nm, about 260 nm, about 270 nm, about 280 nm, about 290 nm, about 300 nm, about 310 nm, about 320 nm, about 330 nm, about 340 nm, about 350 nm, about 360 nm, about 370 nm, about 380 nm, about 390 nm, or about 400 nm, including any value and range therebetween.

[098] The gelling agent may optionally further comprise one or more materials which may be added thereto, for example, to improve the texture of the gel and/or its physical properties, and/or to preserve its contents. These materials may also be added so as to prevent precipitation of the inorganic salt, which leads to decomposition of the gel consistency of the composition. Such materials that are suitable for use in the context of the present embodiments include, without limitation, celite, bentonite, silica (e.g., fumed silica) and povidone (a.k.a. PVD, polyvinylpyrrolidone), which may be used to increase the viscosity of the gel. The appropriate concentration may be determined by one of skill in the art through routine experimentation. [099] In some embodiments, the gel is characterized by a viscosity at the room temperature (e.g., about 25°C).

[100] In some embodiments, the fuel may initially be in gelatin-like state or may be gelled using the selected gelling agent with the ignition agent held in a suspension.

[101] It will be appreciated that the operational conditions for rocket propellant often involve extremely high acceleration forces. The mechanical properties of the gelatinous mixture are preferably such that no sedimentation or coagulation occurs even under such conditions.

[102] Accordingly, in some embodiments, the composition of the invention has a viscosity large enough to prevent sedimentation and/or coagulation of the ignition agent in a condition of e.g., high acceleration, prolonged storage at low temperatures such as between -40 and 0°C, or both.

[103] In some embodiments, the composition of the invention (e.g. the gelled fuel composition comprising the ignition agent, as described herein)is characterized by viscosity ranging from 10 to 10⁵ Pa-s, from 10 to 100 Pa-s, from 100 to 1000 Pa-s, from 100 to 10⁵ Pa-s, from 50 to 10⁵ Pa-s, from 10 to 10⁵ Pa-s, from 10³ to 10⁵ Pa-s, from 10³ to 10⁴ Pa- s, from 10⁴ to 10⁵ Pa- s, including any value and range therebetween.

[104] Viscosity can be measured by any method known in the art, e.g., using a rotating spindle viscometer.

[105] Additionally, or alternatively the viscosity is determined by rheological properties e.g., the yield point, also known in the art as yield stress.

[106] In some embodiments, the composition of the invention (e.g., the gelled fuel composition comprising the ignition agent, as described herein)is characterized by a sufficient yield stress so as to result in a stable composition. In some embodiments, the yield stress of the composition is between 5 and 1000 Pa, between 5 and 1000 Pa, between 5 and 1000 Pa, between 5 and 500 Pa, between 5 and 300 Pa, between 5 and 200 Pa, between 5 and 100 Pa, between 10 and 1000 Pa, between 10 and 500 Pa, between 10 and 300 Pa, between 10 and 200 Pa, between 10 and 100 Pa, between 1 and 1000 Pa, between 1 and 500 Pa, between 1 and 300 Pa, between 1 and 200 Pa, between 1 and 100 Pa, between 1 and 10 Pa, including any range between.

[107] In some embodiments, the composition of the invention (e.g., the gelled fuel composition comprising the ignition agent, as described herein)is characterized by a shear stress of at between 10⁷ and 10 ¹ MPa, between 10⁷ and 10 ¹ MPa, between 10⁷ and 10³ MPa, between 10⁷ and 10⁵ MPa, between 10⁶ and 10 ¹ MPa, between 10⁶ and 10⁴ MPa, between 10⁶ and 10³ MPa, between 10³ and 10 ¹ MPa, including any range between.

[108] The term "fuel" as used herein, refers to any material that can be used to generate energy e.g., to produce mechanical work in a controlled manner.

[109] In some embodiments, the glycol ether (e.g. triglyme) is at a concentration ranging from 1% to 98%, by weight of the fuel. In some embodiments, the glycol ether (e.g. triglyme) is at a concentration ranging from 1% to 90%, by weight of the fuel. In some embodiments, the glycol ether (e.g. triglyme) is at a concentration ranging from 10% to 98%, by weight of the fuel. In some embodiments, the glycol ether (e.g. triglyme) is at a concentration ranging from 20% to 98%, by weight of the fuel. In some embodiments, the glycol ether (e.g. triglyme) is at a concentration ranging from 30% to 98%, by weight of the fuel. In some embodiments, the glycol ether (e.g. triglyme) is at a concentration ranging from 40% to 98%, by weight of the fuel. In some embodiments, the glycol ether (e.g. triglyme) is at a concentration ranging from 50% to 98%, by weight of the fuel. In some embodiments, the glycol ether (e.g. triglyme) is at a concentration ranging from 60% to 98%, by weight of the fuel. In some embodiments, the glycol ether (e.g. triglyme) is at a concentration ranging from 70% to 98%, by weight of the fuel. In some embodiments, the glycol ether (e.g. triglyme) is at a concentration ranging from 80% to 98%, by weight of the fuel. In some embodiments, the glycol ether (e.g. triglyme) is at a concentration ranging from 90% to 98%, by weight of the fuel.

[110] In some embodiments, the glycol ether (e.g., triglyme) is at a concentration of 0.1 %, 1%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 99%, or even 100% by weight of the fuel, including any value there between.

[111] In another aspect of the invention there is provided a hypergolic propellant composition comprising the composition of the invention and a predetermined amount of an oxidizer. In some embodiments, the hypergolic propellant composition can ignite spontaneously, without any energy source. In some embodiments, the predetermined amount of the oxidizer is sufficient for hypergolic ignition of the hypergolic propellant composition.

[112] In some embodiments, the hypergolic propellant composition of the invention comprises triglyme as the fuel, sodium borohydride as the ignition agent, and HP as the oxidizer. [113] In some embodiments, the hypergolic propellant composition of the invention is a fluid. In some embodiments, the hypergolic propellant composition of the invention is a flowable composition. In some embodiments, the hypergolic propellant composition of the invention is a flowable composition, configured for dispensing thereof via injection. In some embodiments, the hypergolic propellant composition of the invention is an injectable composition.

[114] In some embodiments, the hypergolic propellant composition of the invention is characterized by viscosity between 1 and 100.000 cP, between 5 and 100.000 cP, between 10 and 100.000 cP, between 100 and 100.000 cP, between 1 and 1000 cP, between 100 and 1000 cP, between 100 and 10.000 cP, between 10.000 and 100.000 cP, including any range between.

[115] In some embodiments, the predetermined amount of the oxidizer comprises a weight per weight (w/w) ratio between the fuel and the oxidizer within the hypergolic propellant composition of the invention between 1:3 and 1:5, between 1:1 and 1:3, between 1:3 and 1:5, between 1:5 and 1:7, between 1:7 and 1:10, including any range between.

[116] As used herein and in the art, the term "oxidizer" refers to any suitable source of oxygen e.g., for the combustion reaction.

[117] In some embodiments, the oxidizer of the invention is capable of undergo a spontaneous reaction (e.g., without providing any catalyst or any energy) upon contact with the ignition agent. In some embodiments, the oxidizer comprises one or more materials selected from the group consisting of: hydrogen peroxide, cerium, chlorite, bromite, fluorite, chlorate, bromate, fluorate, hyporchlorite, oxygen, nitrous oxide, nitrous acid, nitric acid, and perchloric acid including any salt or any combination thereof. In some embodiments, the oxidizer is or comprises hydrogen peroxide (HP). In some embodiments, the hydrogen peroxide is a high test peroxide characterized by a purity of between 85 and 98% by weight. In some embodiments, the hydrogen peroxide comprises trace amounts of water (e.g., between 1 and 15%) and optionally a metal catalyst.

[118] In some embodiments, the hypergolic propellant composition of the invention ignite generally within about 5 to 15 milliseconds (the ignition delay time). In some embodiments, the disclosed hypergolic propellant composition allows to reduce the ignition delay time to less than 15 milliseconds (ms). In some embodiments, the hypergolic propellant composition is characterized by ignition delay time of less than 10 ms. In some embodiments, the hypergolic propellant composition of the invention is characterized by ignition delay time (IDT) of up to 10ms, up to 9ms, up to 8ms, up to 7ms, up to 6ms, up to 5ms, up to 4ms, up to 3ms, including any value there between.

[119] In some embodiments, the hypergolic propellant composition of the invention is characterized by IDT of between 2 and 8ms including any value there between.

[120] Herein, the ignition delay is determined as the time interval between contact of the oxidizer (e.g., hydrogen peroxide) and the gelled fuel composition and the presence of flame.

Kit

[121] In some embodiments, there is provided a kit of parts comprising a first composition comprising the fuel, the ignition agent dissolved within the fuel, and the gelling agent of the invention (at a concentration ranging between 2 and 8% by total weight of the fuel); and a second composition comprising the oxidizer of the invention. In some embodiments, mixing the first composition with a predetermined amount of the second composition of the kit, results in a hypergolic propellant. In some embodiments, the first composition is the composition of the invention (e.g., the gelled fuel composition, devoid of the oxidizer). In some embodiments, the hypergolic propellant is the hypergolic propellant composition of the invention. In some embodiments, the predetermined amount is a s described herein.

[122] In some embodiments, the first composition and the second composition of the kit are stored separately (e.g., in separate containers). In some embodiments, the first composition of the kit is stored with a first container, and the second composition of the kit is stored within a second container.

[123] One skilled in the rat will appreciate, that upon contact of the oxidizer with the gelled fuel composition a hypergolic ignition will immediately occur. Accordingly, both components (the oxidizer and the gelled fuel composition) has to be stored separately.

[124] In some embodiments, a first container and a second container are sealed containers. In some embodiments, the first container and a second container are separated from each other.

[125] In some embodiments, the first composition and the second composition are mixed only upon use of the propellant. In some embodiments, the first composition and the second composition are mixed within a third container or compartment In some embodiments, the first composition and the second composition are mixed only prior to combustion. In some embodiments, the first composition and the second composition are mixed to initiate combustion.

[126] In some embodiments, a predetermined amount refers to a weight per weight (w/w) ratio between the fuel and the oxidizer to obtain the hypergolic propellant is between 1:3 and 1:5, between 1:1 and 1:3, between 1:3 and 1:5, between 1:5 and 1:7, between 1:7 and 1:10, including any range between.

[127] In some embodiments, the kit of parts is for preparing the hypergolic propellant composition of the invention. In some embodiments, the first composition of the kit of parts first comprises the composition of the invention (e.g., the gelled fuel composition) and wherein the first composition is stable upon storage at temperature ranging from - 40 to +60°C, -40 to -20°C, -20 to -10°C, -10 to 0°C, 0 to 20°C, 0 to +60°C, including any range between. In some embodiments, the first composition and or the entire kit is substantially devoid of a particulate matter upon storage at temperature ranging from - 40 to +60°C upon storage.

[128] In some embodiments, storage is referred to a time interval of between 1 week and 20 years (y), between 1 week and 1 y, between 1 y and 2 y, between 2y and 5 y, between 5 y and 10 y, between lOy and 20 y, including any range between.

[129] As used herein, the term "kit-of-parts" is meant to encompass, inter alia, an entity of physically separated components, which are intended for individual use, but in functional relation to each other.

[130] The container may be used to add liquid to the matrix material prior to use.

[131] In some embodiments, the kit of parts further comprises a means for contacting the fuel and the particle from the first container with the oxidizer from the second container.

[132] As used herein, the term "contacting" refers to the act of touching, applying, injecting, mixing, making contact, or of bringing substances into immediate proximity.

[133] In some embodiments, the means comprises one or more tubes. In some embodiments, the means comprises a third container. In some embodiments, the means comprises a chamber and/or a suction channel.

[134] In some embodiments, the means is a combustion chamber. In some embodiments, the suction channel is pressurized system and/or injection system.

[135] In some embodiments, the means is a third container.

[136] In some embodiments, the kit of parts further comprises an instruction sheet, and/or a label. [137] In some embodiments, the means further comprises a suction channel. In some embodiments, the suction channel is a pressurized system and/or an injection system.

[138] In some embodiments, the kit-of-parts further comprises an instruction sheet. In some embodiments, the kit-of-parts further comprises a label.

Method

[139] In some embodiments, there is provided a method for obtaining the composition of the invention, the method comprising the steps of: a) providing the kit of the invention; and b) mixing a predetermined amount of the second composition of the kit and the first composition of the kit (or the gelled fuel composition), thereby obtaining the hypergolic propellant composition of the invention.

[140] In some embodiments, the method further comprising the steps of: mixing a gelling agent, the ignition agent, and a liquid fuel, thereby obtaining the gelled fuel composition of the invention.

[141] In some embodiments, the predetermined amount comprises a w/w ratio of the oxidizer to the fuel being of between 5:1 and 3:1, between 10:1 and 1:1, between 10:1 and 8:1, between 8:1 and 5:1, between 5:1 and 3:1, between 3:1 and 1:1, including any range between.

[142] The term "obtaining", as used herein, refers interchangeably to providing, producing, and forming, and may include a step of mixing, adding, slurring, stirring, heating, or a combination thereof.

[143] In some embodiments, mixing is performed within the rocket engine. In some embodiments, mixing is performed within the injection system.

General

[144] As used herein the term “about” refers to + 10 %.

[145] The terms "comprises", "comprising", "includes", "including", “having” and their conjugates mean "including but not limited to". The term “consisting of means “including and limited to”. The term "consisting essentially of means that the composition, method or structure may include additional ingredients, steps and/or parts, but only if the additional ingredients, steps and/or parts do not materially alter the basic and novel characteristics of the claimed composition, method or structure.

[146] The word “exemplary” is used herein to mean “serving as an example, instance or illustration”. Any embodiment described as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments and/or to exclude the incorporation of features from other embodiments. [147] The word “optionally” is used herein to mean “is provided in some embodiments and not provided in other embodiments”. Any particular embodiment of the invention may include a plurality of “optional” features unless such features conflict.

[148] As used herein, the singular form "a", "an" and "the" include plural references unless the context clearly dictates otherwise. For example, the term "a compound" or "at least one compound" may include a plurality of compounds, including mixtures thereof.

[149] Throughout this application, various embodiments of this invention may be presented in a range format. It should be understood that the description in range format is merely for convenience and brevity and should not be construed as an inflexible limitation on the scope of the invention. Accordingly, the description of a range should be considered to have specifically disclosed all the possible subranges as well as individual numerical values within that range. For example, description of a range such as from 1 to 6 should be considered to have specifically disclosed subranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6 etc., as well as individual numbers within that range, for example, 1, 2, 3, 4, 5, and 6. This applies regardless of the breadth of the range.

[150] Whenever a numerical range is indicated herein, it is meant to include any cited numeral (fractional or integral) within the indicated range. The phrases “ranging/ranges between” a first indicate number and a second indicate number and “ranging/ranges from” a first indicate number “to” a second indicate number are used herein interchangeably and are meant to include the first and second indicated numbers and all the fractional and integral numerals therebetween.

[151] As used herein the term "method" refers to manners, means, techniques and procedures for accomplishing a given task including, but not limited to, those manners, means, techniques and procedures either known to, or readily developed from known manners, means, techniques and procedures by practitioners of the chemical, pharmacological, biological, biochemical and medical arts.

[152] As used herein, the term “treating” includes abrogating, substantially inhibiting, slowing or reversing the progression of a condition, substantially ameliorating clinical or aesthetical symptoms of a condition or substantially preventing the appearance of clinical or aesthetical symptoms of a condition. [153] In those instances where a convention analogous to "at least one of A, B, and C, etc." is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., "a system having at least one of A, B, and C" would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). It will be further understood by those within the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase "A or B" will be understood to include the possibilities of "A" or "B" or "A and B".

[154] It is appreciated that certain features of the invention, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention, which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable sub combination or as suitable in any other described embodiment of the invention. Certain features described in the context of various embodiments are not to be considered essential features of those embodiments, unless the embodiment is inoperative without those elements.

EXAMPLES

[155] Before giving the examples of embodiments of the invention, it is important to clarify that the invention is not limited to the following set of details exemplified by the embodiments.

[156] Reference is now made to the following examples which, together with the above descriptions disclosed herewith, illustrate the invention in a non-limiting fashion.

EXAMPLE 1

STABILITY OF THE FUEL COMPOSITION

[157] In order to reduce possibility of crystallization/precipitation of sodium borohydride from the fuel (e.g. triglyme) solution, a gelling agent (fumed silica) has been applied. It is postulated, that addition of a gelling agent will result in reduction of dissolved particle’s mobility, which in turn decreases probability of the dissolved particles to collide, recombine and pass the critical particle size threshold for crystallization. [158] In order to confirm this assumption, various fuel compositions have been tested as described hereinbelow.

[159] Solution (I): 10%SBH in Triglyme; Solution (II): 10%SBH + 3%Si02 in Triglyme; Solution (III): 10%SBH + 5%Si02 in Triglyme.

[160] Fumed nano-sized silica powder (SIGMA-ALDRICH®, Catalogue #S5505, 0.2-0.3mhi average particle size (aggregate), 200±25m²/gr surface area ) was used as the gelling agent. The tested solution were stored at about -25 °C in order to promote SBH crystallization. Solutions were stored in 50ml beaker glass, covered with Aluminum foil for about 5days.

[161] Afterwards, images of the samples were acquired with a light microscope (4x magnification and lOx magnification).

[162] The micrographs presented in Fig. 1 depict significant higher crystals accumulation occurred without any gelling agent. Addition of 5% or 3%Si0₂, resulted in a significantly lower crystal formation.

[163] Furthermore, the inventors successfully implemented both triglyme and tetraglyme to obtain a gelled fuel composition of the invention comprising between about 3 and 5%w/w of the gelling agent (e.g., fumed silica) and up to about 10% w/w of the ignition agent (Na-borohydride). The tested gelled fuel compositions have been further characterized by: prolonged storage stability (substantially devoid of particles of the ignition agent, as described herein), and sufficient rheological properties, such as viscosity and shear stress (see Figures 3 and 4) so as to assure stability of the gelled fuel composition upon prolonged storage at low temperature, and/or upon extreme stress conditions such as high acceleration, etc.

[164] In contrast, similar fuel compositions without the gelling agent resulted in a massive development of microparticles (or microcrystals) of Na-borohydride even after short term storage at low temperatures (e.g., below 0 °C).

[165] The inventors postulate that the concentrations of: (i) the gelling agent between 2 and 8%, and (ii) of the ignition agent between 4 and 10% by weight of the fuel within the composition of the invention, are preferable with respect to the stability of the composition and for the use thereof as a propellant, e.g., in a rocket engine.

[166] Ignition Delay Times(IDT) were measured for the 3 solutions, and showed an extremely fast IDT, with increasing time with increasing gellant concentration:

[167] The results indicate that the usefulness of this invention, in terms of ignition delay times, which are below 10 ms, thus pointing out that the exemplified compositions can be utilized as hypergolic fuel compositions.

[168] Furthermore, a rocket engine was ignited and operated using the propellant composition of the invention and Combustion Chamber Pressure was measured. . The test setup included a fuel tank containing the gelled fuel and an oxidizer tank containing -90% hydrogen peroxide. The tanks were pressurized by Nitrogen gas to ~30bars. The pressurized propellants were injected simultaneously, by means of flow control valves (FCVs) and impinging jets injector, into the combustion chamber of ~200mm length with nozzle throat diameter of 16.5mm. In the combustion chamber the hypergolic reaction between the fuel and oxidizer generated high temperature gas-phase products, building pressure and accelerating through the converging-diverging nozzle. The mass Oxidizer to Fuel Ratio (O/F) was approximately 4 during the tests with a total mass flow rate of ~120gr/sec. The results of these tests are represented in Figure 2, demonstrating fast ignition performance, fine response times during pressure build-up and engine shut-off, stabilized combustion chamber pressure, fine repeatability, and combustion efficiencies of 99%, 95% and 86% (figures 2A, 2B and 2C respectively).

[169] All publications, patents and patent applications mentioned in this specification are herein incorporated in their entirety by reference into the specification, to the same extent as if each individual publication, patent or patent application was specifically and individually indicated to be incorporated herein by reference. In addition, citation or identification of any reference in this application shall not be construed as an admission that such reference is available as prior art to the present invention. To the extent that section headings are used, they should not be construed as necessarily limiting.

Claims

WHAT IS CLAIMED IS:

1. A composition comprising a fuel, an ignition agent, and a gelling agent; wherein: said ignition agent is substantially dissolved within the fuel and a gelling agent; said gelling agent is at a concentration ranging from 2% to 8%, by total weight of said fuel; the fuel is a gelled fuel; and the composition is substantially devoid of a particulate matter of said ignition agent.

2. The composition of claim 1, wherein said said ignition agent is at a concentration ranging from 4% to 10%, by total weight of said fuel.

3. The composition of claim 1 or 2, wherein said gelled fuel is characterized by a viscosity being at least 10 times greater than a viscosity of the same fuel without the gelling agent, when measured at 25°C.

4. The composition of any one of claims 1 to 3, wherein said composition is a fluid and is characterized by a viscosity ranging from 10³ to 10⁵ Pa*s, when measured at 25°C.

5. The composition of any one of claims 1 to 4, wherein the ignition agent comprises a metal hydride.

6. The composition of any one of claims 1 to 5, wherein said fuel comprises a glycol ether.

7. The composition of claim 6, wherein said glycol ether comprises any one of a diglyme, a triglyme, a tetraglyme or a combination thereof; and wherein said metal hydride is selected from the group consisting of: sodium borohydride, potassium borohydride, lithium borohydride, lithium aluminum hydride, and a combination thereof.

8. The composition of any one of claims 1 to 7, herein said gelling agent comprises one or more materials selected from a metal oxide nanoparticles, a long chain fatty acid salt, polyacrylate, paraffin, and an alkylated cellulose.

9. The composition of any one of claims 1 to 8, further comprising an oxidizer.

10. The composition of claim 9, wherein said composition is a hypergolic propellant composition, and wherein a weight per weight (w/w) ratio between said fuel and said oxidizer within said composition is at least 1:3.

11. The composition of claim 9 or 10, wherein said oxidizer comprises one or more materials selected from the group consisting of hydrogen peroxide, cerium, chlorite, bromite, fluorite, chlorate, bromate, fluorate, hyporchlorite, oxygen, nitrous oxide, nitrous acid, nitric acid, and perchloric acid including any salt or any combination thereof.

12. The composition of any one of claims 9 to 11, is in a form of a fluid.

13. The composition of any one of claims 9 to 12, wherein a weight per weight (w/w) ratio between said fuel and said oxidizer within said composition is between 1:3 and 1:5.

14. The composition of any one of claims 10 to 13, wherein said hypergolic propellant composition is characterized by ignition delay time of up to 10ms.

15. The composition of any one of claims 10 to 14, wherein the composition is substantially devoid of a particulate matter of said ignition agent upon prolonged storage of said composition at a temperature ranging from -40 to +60°C.

16. A kit of parts comprising:

(a) a first composition comprising a fuel, an ignition agent, and a gelling agent, said gelling agent is at a concentration ranging from 2% to 8%, by total weight of said fuel; the fuel is a gelled fuel; and

(b) a second composition comprising an oxidizer, and wherein upon mixing the first composition with a predetermined amount of the second composition a hypergolic propellant is obtained.

17. The kit of parts of claim 16, wherein said first composition and the second composition are stored in separate containers.

18. The kit of parts of claim 16 or 17, wherein said first composition is substantially devoid of a particulate matter of said ignition agent upon storage at temperature ranging from -40 to +60°C.

19. The kit of parts of claim 16 to 18, wherein the predetermined amount comprises a w/w ratio of the oxidizer and the fuel between 5:1 and 3:1.

20. The kit of parts of claim 16 to 19, wherein said ignition agent is at a concentration ranging from 4% to 10%, by total weight of said fuel.

21. The kit of parts of any one of claims 16 to 20, wherein the ignition agent comprises a metal hydride and said fuel comprises a glycol ether.

22. The kit of parts of any one of claims 16 to 21, wherein the first composition and the second composition are fluids.

23. The kit of parts of any one of claims 16 to 22, wherein the kit further comprises a means for contacting said first composition with said the second composition.

24. The kit of parts of claim 23, wherein said means comprises a chamber and/or a suction channel.

25. The kit of parts of claim 24, wherein said chamber is a combustion chamber; and said suction channel is (i) a pressurized system, (ii) an injection system or both (i) and (ii).

26. The kit of parts of any one of claims 16 to 25, wherein the first composition is the composition of any one of claims 1 to 8.

27. A method for obtaining a hypergolic composition , the method comprising mixing a predetermined amount of said first second composition of the kit of any one of claims 16 to 26; with said first composition of the kit of any one of claims 16 to 26; thereby obtaining said hypergolic composition.

28. The method of claim 27, wherein said predetermined amount comprises a w/w ratio of said fuel to said oxidizer being between 1:3 and 1:5.