Ionic liquids are credited with a number of unusual properties. These include low vapor pressure, wide liquid-phase range, weakly coordinating properties, and high thermal/chemical stability. properties certainly great interest for inorganic synthesis the creation novel compounds. On other hand, repertoire preparing compounds has always been broad, ranging from syntheses in solutions melts to solid-state reactions, crystal growth gas phase high-pressure syntheses. What new aspects can ionic...

Abstract Ionischen Flüssigkeiten wird eine Reihe an ungewöhnlichen Eigenschaften zugeschrieben. Hierzu zählen geringer Dampfdruck, weiter flüssiger Existenzbereich, schwach koordinierende Eigenschaften, hohe thermisch‐chemische Stabilität – die ohne Frage für anorganische Synthese und Herstellung neuartiger anorganischer Verbindungen von großem Interesse sind. Anderseits ist das Syntheserepertoire seit jeher breit reicht Synthesen in Lösungen Schmelzen bis zu Festkörperreaktionen der...

By reaction of elemental bismuth, sulfur, bismuth(III) chloride and gallium(III) in the ionic liquid (BMIm)Cl (BMIm: 1-butyl-3-methylimidazolium), [Bi3GaS5]2[Ga3Cl10]2[GaCl4]2·S8 is obtained as red transparent crystals. According to X-ray structure analysis based on single crystals, title compound crystallizes with triclinic lattice symmetry composed heterocubane-type [Bi3GaS5]2+ cations, trimeric star-shaped [Ga3Cl10]− anions three (GaCl4) tetrahedra sharing a central chlorine atom,...

Abstract This article gives a short review on compatibility and chemical stability of selected aqueous ADN HAN‐based energetic formulations. A brief introduction will outline Energetic Ionic Liquids (EILs) as new class materials with beneficial physical‐chemical properties which make them valuable for application in propulsion technologies. EILs combine the advantages e. g. low toxicity, showing equal or superior power compared to state‐of‐the‐art monopropellant hydrazine. Focus is set open...

Abstract By reaction of elemental tellurium, tellurium(IV) chloride, tantalum(V) chloride and oxychloride in the ionic liquid [BMIM]Cl ([BMIM]Cl:1‐Butyl‐3‐methylimidazolium chloride),[Te 8 ] 2 [Ta 4 O Cl 16 is obtained form lucent black crystals. The title compound consists infinite [Te–Te–(Te 6 )] n 2+ chains (Te–Te: 264.9(1)–284.3(1) pm) isolated 4– anions. are interconnected to a two‐dimensional tellurium network 335.9 pm). Due this interaction [Te show an arrangement that differs...

Ionic liquids are promising candidates for future fuels in space propulsion. In this work, six ionic with thiocyanate anions proposed as new fuel hydrogen peroxide an oxidizer. The influence of the cation is studied by pyridinium- and pyrrolidinium-based various alkyl chains. Characterization comprises, inter alia, thermal analysis, viscosity, density measurement. Calculations theoretical performance hypergolic propellants were performed NASA Chemical Equilibrium Applications comparison...

Abstract Three trialkylsulfonium thiocyanate ionic liquids (ILs) are presented as fuel candidates for novel green hypergolic propellants. The physical and chemical properties such density, viscosity, melting point decomposition temperature well the enthalpy of formation ILs were determined. Further, research focused on potential components propellants with highly concentrated hydrogen peroxide oxidizer. For this, theoretical maximum specific impulses calculated NASA CEA. To evaluate ignition...

Abstract Microencapsulated ionic liquids (ILs) have a wide range of exciting properties. They can be synthesized by variety methods, which interfacial polymerization represents very simple, fast, and reliable production process, but the number available shell materials that obtained this method is limited. However, recent advances in field described formation polyamide membrane at IL/organic phase interface, extended work to first microencapsulation ILs with shell, providing an additional...

As of now, the most widely used hypergolic fuels are hydrazine derivates with nitrogen tetroxide as oxidizer. The toxicity and carcinogenic character these substances make their handling challenging even if gelled. Therefore, there is great interest throughout propulsion community in finding alternatives for substances. However, despite a thorough literature review, clear selection criteria "green" hypergols could not be found. To tackle this issue, we developed set key requirements...

Regarding the research on alternatives for monopropellant hydrazine, several so called green propellants are currently under investigation or qualification.Aside others, DLR Institute of Space Propulsion investigates a N 2 O/C H 4 premixed propellant.During activities, flashback from rocket combustion chamber into feeding system has been identified as major challenge when using propellant mixture.This paper shows results ignition experiments conducted in cylindrical, optical accessible...

Transpiration cooling systems are a promising approach to handle the high wall temperatures and heat loads generated in supersonic combustion ramjets (scramjets). The German Aerospace Center DLR has developed set up versatile test bench investigate applicability of transpiration scramjets the phenomena resulting out interaction between such system, optional shock generators like wedge shaped struts hot gas main flow. In publication at hand, its components presented detail, as well...

In recent investigations at DLR Lampoldshausen a highly active catalytically promoted ionic liquid fuel with hydrogen peroxide was found. This is based on an and dissolved metal salt as catalytic promoter. But due to high viscosity of this bad mixing behaviour between reliable ignition not achieved. investigation introduced different amounts organic solvent the drop test were conducted evaluate hypergolic performance. Repeatable achieved delay times around 28 ms.

[BMIm]4[AgMo10Cl35] is prepared by reaction of MoCl5 and elemental silver in the ionic liquid [BMIm][AlCl4] ([BMIm(+)]: 1-butyl-4-methylimidazolium). Surprisingly, oxidized under these conditions. The title compound contains a new wheel-shaped [Mo10Cl35](5-) chlorido molybdenum(iii) species with five pairs Mo-Mo bonds. distances are found to be 263 pm on average. wheels exhibit maximum opening 558 diameter. They interlinked via Ag(+) form infinite [AgMo10Cl35](4-) chains. characterized...

The title compound, [Te(8)][NbOCl(4)](2), was obtained as translucent black crystals by reaction of elemental tellurium, niobium(V) chloride and oxychloride in the ionic liquid BMImCl (BMImCl is 1-butyl-3-methylimidazolium chloride). synthesis performed argon-filled glass ampoules. According to X-ray structure analysis based on single crystals, compound crystallizes with triclinic lattice symmetry consists infinite {[Te(8)](2+)}(n) cations associated pyramidal [NbOCl(4)](-) anions. novel...

A theoretical screening and experimental characterization of the hypergolicy different ionic liquids in combination with highly concentrated hydrogen peroxide was conducted. The aim investigation to find a possible alternative hypergolic bipropellant substitute commonly used propellant combinations hydrazines dinitrogen tetraoxide. Highly chosen as green oxidizer, were fuels. Ionic offer very low vapor pressures compared common fuels, which allows simplified handling procedures. focused on...

Investigations for the development of new liquid green hypergolic propellants are carried out by Propellants department DLR Lampoldshausen. One part includes testing under flowing conditions to determine ignition delay time. Therefore an injector test setup was designed and put into operation. For first tests a proven propellant consisting Block 0 highly concentrated hydrogen peroxide chosen. Drop with were conducted. The average time 20.5 ms. 2on1 impinging manufactured. minimum during 190

Abstract This work demonstrated the large potential of sputtered iridium metal for catalytic reactions shown by example decomposition hydrogen peroxide (H 2 O ) space propulsion systems. For this purpose, was coated onto Al 3 pellets a sputter process under varied parameters. Depending on previously selected parameters, obtained metal-loaded offer closed- and/or open-shell structures. Catalytic productivity these first-generation iridium-sputtered catalysts estimated in laboratory...

The German Aerospace Center’s Institute of Space Propulsion in Lampoldshausen has more than a decade experience green propellant research and propulsion hardware development for in-orbit applications. In the frame internal projects, ESA third-party projects DLR researcher gained deep extensive knowledge on associated systems, technologies. Currently, several promising technologies are investigated developed parallel, namely HyNOx mono- bipropellant technology, based nitrous oxide hydrocarbon...

For the development of advanced materials and structures with improved corrosion abrasion resistance, a better understanding complex multiphase flow/structure interaction is necessary. Besides appropriate material ceramic matrix composites (CMC) concerning harsh application conditions, precise characterization respect to compatibility relevant fuels on aging aspects and, especially, performance application-related combustion tests for ramjet scramjet propulsion are special interest. In order...