Pure Hydrazine Research Articles

Impure Hydrazone Preparation from Chicken Dung

Hydrazones are strong reducing agents. Some hydrazones like hydrazine are is highly toxic and unstable and are therefore found dissolved in water. Chicken dung contains amines and uric acid that are potential sources of hydrazones. This paper reports on the use of chicken dung as an important raw material for the industrial hydrazones. In this study, we investigated the conversion of amine to amide compounds in chicken dung and later chlorine treatment to produce impure hydrazones. In the preparation, 1.0 kg of the chicken dung was soaked in 2.0 litres of distilled water for fifteen days. After filtration, the leachate obtained was treated with chlorine gas. The chemical conversion of the compounds in the chicken dung leachate before and after chlorination was monitored using FT-IR and MS. A sample of pure hydrazine hydrate was analyzed using the two techniques and the spectra obtained was used as a reference standard. The findings of this study indicate that chicken dung is rich in amine-containing compounds that can be converted to amide derivatives under ambient conditions. A comparison of FT-IR and MS data before and after chlorination indicated the formation of hydrazones. The findings of this study provide some scientific rationale for using chicken dung as an alternative source of industrial hydrazones. Keywords: Hydrazones, amines, amides, chicken dung. DOI: 10.7176/CMR/12-7-02 Publication date: September 30 th 2020

Density-functional study of hydrazine doped single-walled carbon nanotubes as an n-type semiconductor

The theoretical study of hydrazine in the presence of moisture doped single-walled carbon nanotube (SWCNT) where the donor state (DS) occurred in the electronic band structure, which has previously been reported. Herein, We reveal that the density functional theory (DFT) studies of pure hydrazine formed the hydrogen bond network (HBN) on SWCNT, leading to the n-type behavior. DFT approaches including van der Waals corrections were carried out to understand the specific configuration of hydrazine, which causes the occurrence of the DS. The electronic band structures are classified according to three groups. First, is the impurity state below the maximum valence state (ISBMVS). Second, is the impurity state close to (below) the maximum valence state (ISCMVS), and third, is the DS. The reduced density gradient (RDG) approach and the Bader charge analysis were used to address a specific hydrazine molecule, which caused the DS to occur. The NMR chemical shifts and UV–Vis spectroscopic parameters can be used for comparison with experiments to confirm the theoretical models. • The electronic calculation reveals hydrazine doped SWCNTs are n-type semiconductors. • Effect of structure optimization was found crucial to discover a specific hydrogen bonded on hydrazine network. • 13 C NMR and 1 H NMR data were analyzed via periodic DFT calculations. • The proposed of photon absorption energy and optical transition in IS and DS with TDDFT framework are agreement with experimental data.

Synthesis of thienopyridinones via hydrazide-alkyne cyclization

A novel and efficient method for the synthesis of thieno[3,2-c]pyridinones have been developed. The synthetic strategy relies on the synthesis of halothiophene esters utilized as substrates for subsequent Sonogashira cross-coupling reactions. Hydrazinolysis of corresponding esters and following hydrazide-alkyne ring closure transformations resulted in target thienopyridinones in good yields. It is also shown that pure hydrazine monohydrate is required to facilitate the hydrazide formations.

Экспериментальное исследование плотности и теплоeмкости жидкого чистого гидразина при введении в него чистых сухих фуллеренов

The paper presents the results of experimental investigation concerning the introduction of non-metallic nano-additives — pure dry fullerenes of C60, C70, C84 grades — into liquid pure hydrazine. The study shows the effect of fullerenes on increasing the efficiency of liquid pure hydrazine by changing its density and thermal capacity through the relative coefficients of the system "(hydrazine + fullerenes) / hydrazine" at temperatures T = 293…560 K and pressures P = 0,101…49.01 MPa. The ways of increasing the efficiency of aircraft engines and power plants and aircraft themselves with the use of a new fuel type "hydrazine — fullerenes" have been developed. Findings of the study are new and necessary for calculations on making efficient jet engines and power plants of expendable and nonexpendable aircraft for ground, air, aerospace and space-based dual-use basing.

Экспериментальное исследование плотности и теплоёмкости жидкого чистого гидразина

The paper presents the results of experimental investigation concerning density and thermal capacity of liquid pure hydrazine undergoing natural convection when heated to Т = 293…560 K and subjected to pressure р = 0.101 MPa. We compare the results obtained to results published previously elsewhere, revealing inaccuracies in equations used to compute density and thermal capacity. Analysing the experimental results obtained enabled us to develop new equations that ensure highly accurate computations of density and thermal capacity of liquid pure hydrazine. This submission becomes extremely important, as pure liquid hydrazine is widely used in expendable and non-expendable liquid rocket engines, especially in expendable and non-expendable low-thrust liquid rocket engines and liquid micro-rocket engines, which makes it impossible to develop and build novel promising engines without accurate equations for computing density, thermal capacity and other thermophysical properties of the fuel. Moreover, the investigation results and the innovative accurate equations derived by the authors allow us to conduct other experimental studies dedicated to increasing the density and other thermophysical properties of liquid pure hydrazine, for example, by means of introducing dry fullerenes into the hydrazine or employing electrostatic fields, which will be further described in detail in the papers to follow.

Экспериментальное исследование теплофизических свойств жидкого чистого гидразина при различных температурах и давлениях

The paper studies the areas of application of liquid pure hydrazine and its derivatives. In order to obtain the complete information about its thermophysical properties, we carried out the experimental studies in a wide range of pressure and temperature parameters under conditions of natural convection. To conduct such studies, experimental facilities and work sites were constructed on which various modern methods were implemented. As a result, it was possible to determine the thermophysical properties of liquid pure hydrazine with high accuracy. Findings are presented in tables. Moreover, we developed methods to improve the efficiency of using liquid pure hydrazine, which will increase the efficiency of liquid rocket engines and single-and-multi-use power plants for air-launched, aerospace-based and space-based aircraft.

Sodium Hydrazinidoborane: A Chemical Hydrogen‐Storage Material

Herein, we present the successful synthesis and full characterization (by (11) B magic-angle-spinning nuclear magnetic resonance spectroscopy, infrared spectroscopy, powder X-ray diffraction) of sodium hydrazinidoborane (NaN2 H3 BH3 , with a hydrogen content of 8.85 wt %), a new material for chemical hydrogen storage. Using lab-prepared pure hydrazine borane (N2 H4 BH3 ) and commercial sodium hydride as precursors, sodium hydrazinidoborane was synthesized by ball-milling at low temperature (-30 °C) under an argon atmosphere. Its thermal stability was assessed by thermogravimetric analysis and differential scanning calorimetry. It was found that under heating sodium hydrazinidoborane starts to liberate hydrogen below 60 °C. Within the range of 60-150 °C, the overall mass loss is as high as 7.6 wt %. Relative to the parent N2 H4 BH3 , sodium hydrazinidoborane shows improved dehydrogenation properties, further confirmed by dehydrogenation experiments under prolonged heating at constant temperatures of 80, 90, 95, 100, and 110 °C. Hence, sodium hydrazinidoborane appears to be more suitable for chemical hydrogen storage than N2 H4 BH3 .

Hydrazine Borane: A Promising Hydrogen Storage Material

We describe an easy method of improving the promising hydrogen storage capabilities of hydrazine borane by adding an equimolar amount of lithium hydride. The resulting mixture contains 14.8 wt % H(2). The hydrogen release behavior of both the pure hydrazine borane and the LiH mixture was studied at various temperatures and showed excellent hydrogen release rates at a reasonable temperature range of 100-150 degrees C.

High-throughput solution processing of large-scale graphene

The electronic properties of graphene, such as high charge carrier concentrations and mobilities, make it a promising candidate for next-generation nanoelectronic devices. In particular, electrons and holes can undergo ballistic transport on the sub-micrometre scale in graphene and do not suffer from the scale limitations of current MOSFET technologies. However, it is still difficult to produce single-layer samples of graphene and bulk processing has not yet been achieved, despite strenuous efforts to develop a scalable production method. Here, we report a versatile solution-based process for the large-scale production of single-layer chemically converted graphene over the entire area of a silicon/SiO(2) wafer. By dispersing graphite oxide paper in pure hydrazine we were able to remove oxygen functionalities and restore the planar geometry of the single sheets. The chemically converted graphene sheets that were produced have the largest area reported to date (up to 20 x 40 microm), making them far easier to process. Field-effect devices have been fabricated by conventional photolithography, displaying currents that are three orders of magnitude higher than previously reported for chemically produced graphene. The size of these sheets enables a wide range of characterization techniques, including optical microscopy, scanning electron microscopy and atomic force microscopy, to be performed on the same specimen.

Design and Use of a Batch Reactor for Catalytic Decomposition of Propellants

The toxicity of pure hydrazine has prompted the research of possible green to replace this mono-propellant for small thruster use. To fulfill this objective, a constant volume computerized batch reactor has been developed, which permits study of different monopropellants and their associated catalysts. This reactor can be used as a screening reactor, and its main advantages are easy use, fast change of catalyst or propellant, very limited consumption of propellant or catalyst, and simultaneous recording of reactor pressure, catalyst, and gas-phase temperatures. The catalyst can be preheated, and the working pressure is between vacuum and 2 bars. The main parameters that can be obtained for the catalyst evaluation are the catalytic decomposition rate, the ignition delay, and the onset decomposition temperature. Three propellants have been checked: pure hydrazine, hydrogen peroxide, and a hydroxylammonium nitrate-(HAN-)triethanolammonium nitrate-(TEAN-) water mixture; they display similar rates and ignition delays but the HAN-based propellant needs higher initial temperature and leads to the simultaneous formation of condensed products at low temperature. For a specific propellant, the results lead to a classification of different catalytic beds before further investigations in dynamic reactors using real working conditions.

Critical reactions for the hydrazine vapor detonations

A detailed kinetic model devoted to the hydrazine vapor detonation has been built. It consists of 33 reversible reactions and 13 species. A reduced kinetic model has been proposed by using the Principal Component Analysis of matrix F (PCAF) method as implemented in KINALC. It is constituted of 26 reactions and 11 species. This model has been shown to be valid over a pressure range of 0.1 to 10 atm. However, the predictions of the models are significantly affected by changes in the enthalpy of formation of N $_2$ H $_3$ . With the help of the full kinetic model, a value of A, the proportionality factor in the ZND model between the induction distance in the detonation wave and the detonation cell size, of $27.5 \pm 3.0$ has been derived if one considers that the collision efficiency of N $_2$ H $_4$ on the thermal decomposition of hydrazine is equal to the one of N $_2$ . The value of A for pure hydrazine detonation is shown to be strongly dependent on the value of the collision efficiency of N $_2$ H $_4$ .

Kinetic modeling of the decomposition and flames of hydrazine

A detailed N/H reaction mechanism has been developed and validated by comparing modeling results with measurements of hydrazine pyrolysis in shock waves, and in hydrazine decomposition flames at low and atmospheric pressures. The mechanism consists of 51 reactions for 11 species. Rate constants for several decomposition reactions have been estimated employing updated thermodynamic data. Analysis of the reactions abstracting an H atom from NH 3, NH 2, NH and N 2H 4 from 1000 to 2000 K demonstrates that the Evans-Polanyi correlation holds for the radicals H, NH, and NH 2. Probably it is also valid for the radicals N, NNH and N 2H 3. Several rate constants were estimated with this assumption. No further adjustment of the mechanism was attempted. The modeling correctly reproduces the experimental rate of decomposition of hydrazine and also the product distribution. The initial decomposition of N 2H 4 into two NH 2 radicals and the subsequent reaction N 2H 4 + NH 2 → NH 3 + N 2H 3 mainly govern the decomposition of hydrazine in dilute mixtures and together with the reaction NH 2 + NH 2 → N 2H 2 + H 2 control the propagation speed of a hydrazine flame. The computed speeds of such decomposition flames agree well with low-pressure and atmospheric pressure experiments for pure hydrazine and its mixtures with Ar, N 2, H 2O and NH 3. Also the concentration profiles of major and minor species in low-pressure hydrazine flames are well reproduced. A sensitivity analysis identifies the critical reactions in particular experimental conditions. The choice of rate constants for key reactions and further development of the mechanism is discussed.

Pervaporation of water, hydrazine and monomethylhydrazine using ethylcellulose membranes

Ethylcellulose membrane has been selected on the basis of Hansen's solubility parameter and Flory–Huggins interaction parameter for the enrichment of hydrazine and monomethylhydrazine (MMH) liquid propellants by pervaporation. An extensive study of the overall mass transfer resistance experienced by the permeants has been conducted. The resistance values were quantitatively estimated by changing the membrane thickness and calculating the corresponding flux. Due to its lower sorption, and fewer interactions, the membrane showed least desorption resistance towards water and thus it is permselective with respect to water. Results of pervaporation selectivity obtained in separation of water–hydrazine and water–MMH mixtures at azeotropic compositions have been correlated. Higher sorption of MMH and hydrazine did not result in preferential separation inspite of lower membrane resistance. Experimental results clearly showed that desorption resistance and diffusivity were predominant over the respective solubilities. To confirm the reasons for these phenomena, FTIR and DSC spectra of membranes soaked in pure hydrazine, MMH, water and hydrazine hydrate were compared.

Diode-laser absorption measurements of hydrazine and monomethylhydrazine

Absorption measurements of pure hydrazine, N 2H 4, and monomethylhydrazine, CH 3N 2H 3 (MMH), were recorded in an optical absorption cell (3 passes, 50 cm/pass) at low pressure (0–35 Torr) using a tunable external-cavity diode laser (ECDL), operating in the range from 6350 to 6650 cm -1 (1.49 to 1.58 μm). Peak absorption cross-section measurements of hydrazine and MMH, as determined from fixed wave-length absorption measurements, were found to be α e( ν)=0.163±0.008 cm -1atm -1 at 6495 cm -1 ( λ=1539.6 nm) and α e( ν)=0.152±0.003 cm -1atm -1 at 6560 cm -1 ( λ=1524.4 nm), respectively.

Low Temperature Chemical Vapor Deposition of Titanium Nitride Thin Films With Hydrazine and Tetrakis-(dimethylamide)Titanium

AbstractHydrazine and tetrakis-(dimethylamido)titanium have been used as precursors for the low temperature chemical vapor deposition of TiN thin films between 50°C and 200°C at growth rates between 5 to 35 nm/min. At hydrazine to TDMAT ratios of 50:1 and 100:1 the resulting films show an increase in the Ti:N ratio with increasing deposition temperature. They contain 2% carbon, and varying amounts of oxygen up to 36% as a result of diffusion after air exposure. The low temperature growth is improved when hydrazine-ammonia mixtures containing as little as 1.9% hydrazine are used. Their Ti:N ratio is almost 1:1 and they contain no carbon or oxygen according to RBS. The TiN films grown from pure hydrazine or the hydrazine-ammonia mixture have some crystallinity according to x-ray diffraction and their resistivity is on the order of 104µω cm. The low temperature growth is attributed to the weak N–N bond in hydrazine and its strong reducing ability. In these films, the Ti:N ratio is approximately 1:1.

Asymmetric syntheses via metalated chiral hydrazones : Overall enantioselective α-alkylation of acyclic ketones

A general method is described, which allows the overall enantioselective α-alkylation of acyclic ketones in good overall yields (44–86%,, 4 steps) and enantioselectivities ranging routinely from > 94% ee up to virtually complete asymmetric induction (99.5% ee). The acyclic ketones are transformed to their corresponding “SAMP-hydrazones” ( S)- 2 by reaction with the enantiomerically pure hydrazine ( S)-l-amino-2-methoxymethyl-pyrrolidine [ SAMP, ( S)- 1], readily available from ( S)-proline. Metalation to form chiral azaenolates ( S)- 3 of E ccZ cn-configuration and then alkylation to product hydrazones 4 followed by hydrazone cleavage via acidic hydrolysis of methiodides 9 in a two phase system or ozonolysis, leads to α-substituted, enantiomerically enriched, acyclic ketones 5. In special cases, where a phenyl group is directly attached to the newly generated center of chirality ( 5n, o, p), only low enantiomeric excesses are observed. 17 Examples, including first applications in natural product synthesis (cf 5abe and h) are summarized

Use of hydrazine salts as modifying agents for polyacrylonitrile in the preparation of carbon fibres

Polyacrylonitrile (PAN) fibres are used as a raw material for the preparation of highmodulus and high-strength carbon fibres [i]. Sometimes, with the objective of cutting down the time for thermal stabilization of the fibres, they are treated in the presence of cyclization catalysts. These catalysts are substances which aid in the dehydrogenation of hydrocarbons or the dehydrogenation of hydroxyl-containing organic compounds, for example ZnCI2, AICI3, or FeCI3 [2]. Compounds of the Lewis acid type [3], acids, or alkalis can serve as catalysts [i]. In our research we used salts of hydrazine as modifiers-- the hydrochloride and the sulfate, and also combinations of hydrazine salts with caustic soda. Modification of the PAN fibres was carried out at 343°K in solutions whose concentration was from 0.5 to 20% by wt. The length of the treatment was i ho When the salt-NaOH system was used, the ratio of the components in the solution was varied from i:i to 2:1. After treatment, the fibre was subjected to oxidation in a heating chamber. The color of the fibres hardly changes if they are treated with the pure salts. Addition of alkali leads to a change in color from white to dark yellow. For comparison we carried out experiments on modification of fibres with caustic soda solutions alone. At a solution concentration greater than 0.5%, the morphological structure of the fibre is destroyed. Treatment of PAN fibres with hydrazine salts leads to an increase in the strength of the carbon fibres (Fig. i)o Treatment with salts at low concentration, 0.5-1% by wt., exerts the most important effect on the strength of the carbon fibres; the increase in their strength on treatment with 15 or 20% solutions of the salts is slight° The strength of the carbon fibres obtained by modification of PAN fibres with pure hydrazine, salts remains below the strength of the fibre obtained asa result of adding the salt--NaOH system. The difference in strength of the carbon fibres at various ratios of the components in this system is small; it is more prominent when the PAN fibres are modified with hydrazine sulfate° Within definite limits, the additions of alkali aids in raising the pH of the medium and favorably affects the quality of the carbo~ fibres, Treatment in an alkaline medium in combination with the cross-linking action of the hydrazine [4],which is liberatedondissociation of the salt, leads in the end to an increase in the strength of the carbon fibres. This fact may be explained by structural changes in the PAN fibres during the modification process. These changes are recorded on a differential scanning calorimeter, where the thermal effects of the cross-linking process are determined, which are characterized by the specific enthalpy values: Fibre AH, J/g

Quenching, radical formation, and disproportionation in the photoreduction of 4-carboxybenzophenone by 4-carboxybenzhydrol, hydrazine, and hydrazinium ion

Laser flash and steady irradiation studies have been carried out on the 4-carboxybenzophenone (CB)-4-carboxy-benzhydrol (CBH/sub 2/) and CB-hydrazine systems over the pH range 5.8 to 12. In reaction with CBH/sub 2/, CB triplet is quenched in part by the carboxylate, k/sub q/ approx. = 4 x 10/sup 6/ M/sup -1/s/sup -1/; total reaction, k/sub 4/ = 3.0 x 10/sup 7/ M/sup -1/s/sup -1/ leads to the ketyl radical CBH, phi = 1.7. Absorption spectra were recorded for CB triplet, lambda/sub max/ = 535 nm (epsilon = 6600 M/sup -1/ cm/sup -1/), for CBH, lambda/sub max/ = 570 nm (epsilon = 5500), and for the radical anion CB/sup -/, lambda/sub max/ = 660 nm (epsilon = 8100). The pKa ofCBH was determined, 8.2. Rate constants were determined: for combination of CBH to pinacol, 2k/sub 6/ = 1.8 x 10/sup 9/ M/sup -1/s/sup -1/; for reactions of CBH with CB/sup -/, k/sub 7/ = 1.1 x 10/sup 9/ M/sup -1/s/sup -1/; for disproportionation of 2CB/sup -/, 2k/sub 8/ = 9.8 x 10/sup 6/ M/sup -1/s/sup -1/. Factors to convert observed yields of photoreduction by hydrazine to yields of ketyl radical leading to pinacol and hydrol were determined from effects of pH onmore » quantum yields of reduction of CB by CBH/sub 2/. Reduction of CB triplet by neutral hydrazine occurs with k/sub ir/ = 6.8 x 10/sup 8/ M/sup -1/s/sup -1/, forming ketyl radical with phi = 1.0, measured relative to the CBH/sub 2/ reaction. The reaction with protonated hydrazine is slower, k'/sub ir/ = 4.4 x 10/sup 6/ M/sup -1/s/sup -1/. Computer simulation, using the measured rate constants, pK/sub a/ and primary yields, and literature constants for pure hydrazine systems, leads to calculated reduction yields very similar to the observed values, with phi/sub ketyl/ approx. = 0.0 for reaction of triplet with protonated hydrazine, and ratios of rate constants for ketyl-hydrazyl disproportionations appropriately close to unity.« less

Pulse radiolytic formation of solvated electrons in hydrazine

The spectrum and yield of solvated electrons in anhydrous hydrazine have been investigated by pulse radiolysis. At room temperature the optical absorption band has a maximum at 1.22 eV (1015 nm) with a molar extinction coefficient of 2.2 ± 0.1 × 104 M−1 cm−1 and a temperature coefficient of 1.5 × 10−3 eV deg−1 from 7–45 °C. The oscillator strength is estimated to be 0.6. The optical transition energy is in reasonable agreement with an empirical correlation of solvent properties proposed by Freeman provided that only the polarisability of the nitrogen lone-pair electrons contribute to Emax. Comparisons are made with liquid amides which also have lone-pair polarisable groups and with water and liquid ammonia which have physical properties very similar to hydrazine. Electron yields increase from [Formula: see text] in pure hydrazine to 2.65 + 0.15 in basic solutions containing ≥0.1 M sodium hydrazide.

Hydrazine Decomposition in Glow Discharge

Glow-discharge decomposition of pure hydrazine in a flow system was studied at an inlet temperature of 25°C for several currents and flow rates. The emission spectrum from 3000 to 6000 Å was observed. Stable products were analyzed using gas chromatography. An important characteristic of the decomposition is the observation of an initial threshold level of hydrazine decomposition. The principal feature of the proposed reaction mechanism is the use of competitive reactions involving the rupture of the N–H and N–N bonds.