Combustible metal hydrazine

There is hysteresis in reaction, but copper salts if added, such as in the form of K3Cu(CN)4 can help catalyze the reaction and the salt dissolves into hydrazine hydrate. It was further confirmed that K3Cu(CN)4 reacts with hydrazine at room temperature to form copper metals whose accumulation could block hydrazine from entering combustion chamber. To remove such a possibility, before entering combustion chamber hydrazine hydrate should go through a cartridge of copper nitrate which are able to accelerate the reaction. 

Several nanocrystalhne metal oxides have been prepared by the combustion method and the topic has been reviewed by Patil et al. [5]. Combustion of metal hydrazine carboxylates, [e.g. MCjO (N H )J is generally anployed to obtain the nanoparticles of oxides such as y-Fefiy ZnO and NiO. Mixed-metal oxides like cobaltites (MCo O ), ferrites (MFe,0 ), manganites (MMn O ) and titanates (MTiOj) are prepared by the combustion of mixed-metal carboxylate hydrazinates in the temperature range of 165-345 °C [6,7]. Solution combustion synthesis has been used to prepare nanocrystalline oxides such as Al Oj, CeO, ZrO, TiO, ... 

Patil, K.C. and Seker, M.M.A. (1994) Synthesis, structure and reactivity of metal hydrazine carboxylates combustible precursors to fine particle oxide materials. International Journal of Self-Propagating High-Temperature Synthesis, 3, 181-196. 

The combustible nature of metal hydrazine complexes and the high exothermicity realized during heating have paved the way for using them as precursors to several useful nanocrystalline metal powders and oxide materials like Fe304, -FesOs, ferrites, cobaltites, manganites, and so on. 

It is easy to dope metal ions in metal hydrazine complexes as well as to make solid solutions of them (discussed in Chapter 4). The combustion of these metal-ion substituted metal hydrazine carboxylate complexes in air yield the corresponding nanocrystalline oxide materials with interesting catalytic, magnetic, and dielectric properties, having applications as phosphors, pigments, and so on. A few examples of the interesting... 

The discovery, through serendipity, that the combustion of iron hydrazine carboxylate yields nano-iron oxide led to the preparation of various nanosize oxide materials by the thermal reactivity of metal hydrazine carbox-ylates. Hitherto, oxide materials prepared by conventional ceramic techniques used hydroxides, carbonates, nitrates, or oxalates as starting materials. The procedure involves their repeated pulverization and... 

The formation of cobaltites (MC02O4) from the combustion of mixed metal oxalate/acetate hydrazine complexes and solid solutions of hydra-zinium metal hydrazine carboxylate hydrates have been discussed in Chapters 3 and 4, respectively (Sections 3.2.4.1, 3.2.6 and 4.6). The final product, confirmed by X-ray diffraction pattern, shows the characteristics of cobaltite spinels. Similar to cobaltites, mixed metal oxalate/acetate hydrazines complexes undergo single-step decomposition to form... 

Chlorine dioxide Copper Fluorine Hydrazine Hydrocarbons (benzene, butane, propane, gasoline, turpentine, etc) Hydrocyanic acid Hydrofluoric acid, anhydrous (hydrogen fluoride) Hydrogen peroxide Ammonia, methane, phosphine or hydrogen sulphide Acetylene, hydrogen peroxide Isolate from everything Hydrogen peroxide, nitric acid, or any other oxidant Fluorine, chlorine, bromine, chromic acid, peroxide Nitric acid, alkalis Ammonia, aqueous or anhydrous Copper, chromium, iron, most metals or their salts, any flammable liquid, combustible materials, aniline, nitromethane... 

Salts of very powerful oxidizing acids (eg chromic or permanganic) are unknown, and are unlikely to exist. Hydrazonium iodate may exist in solution at low temp (Ref 27a). Alkali metals, amides and hydrides react with hydrazine to give the corresponding alkali hydrazide. Sodium hydrazide explodes violently in the presence of 02 or when heated above 100°C—a typical behavior of the alkali hydrazides. For other reactions, see Ref 24 Explosive and Combustion Properties... 

Mechanism for Deriving Energy. The mechanism by which propulsive energy is derived from propellant systems containing metals and their compounds is somewhat different from that of conventional liquid propellant systems. For hydrazine and nitrogen tetroxide, for example, their combustion leads to the formation of N2, H20, and H2 through a relatively simple series of intermediate species ... 

Utilization of Multicomponent Propellants. One approach to the utilization of a metallized system such as that involving hydrazine, aluminum, and oxygen is to inject the three components separately into the combustion chamber (tripropellant system). This avoids the problems associated with the suspension of the metal in the fuel or oxidizer (and is therefore not a heterogeneous propellant), but it imposes other prob-... 

As reaction is preceded by a certain delay, this induction period was reduced by the addition of copper salts, e.g. potassium cuprocyanide K3Cu (CN)4. This substance was supplied to the system dissolved in the hydrazine hydrate. It was found that potassium cuprocyanide reacts with hydrazine even at room temperature to form metallic copper which, if deposited in the pipelines, may cut off the flow of hydrazine into the combustion chamber. To prevent this the system was modified so that hydrazine hydrate flowed from the tank into the combustion chamber through a cartridge containing cupric nitrate, which dissolved in hydrazine hydrate in a sufficient quantity to accelerate the reaction (hydrazine and its reaction with H202 will be discussed in more detail further on). 

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