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Showing papers on "Ammonium perchlorate published in 2008"


Journal ArticleDOI
TL;DR: In this article, the authors used X-ray diffraction (XRD), thermogravimetric (TG) analysis coupled with differential thermal analysis (DTA), transmission electron microscope (TEM), Brunauer-Emmett-Teller (BET) technique, and Fourier transformation infrared spectroscopy (FTIR) for ammonium perchlorate (AP) decomposition.

245 citations


Journal ArticleDOI
TL;DR: In this paper, nanorods and octahedrons of α-Fe 2 O 3 were selectively synthesized through one-step hydrothermal treatment of iron(III) chloride in aqueous formamide solution for different time.

165 citations


Journal ArticleDOI
TL;DR: The variations of photoluminescence spectra and catalytic roles in ammonium perchlorate decomposition were discussed in terms of the defect structure of ZnO twin-cones.
Abstract: ZnO twin-cones, a new member to the ZnO family, were prepared directly by a solvothermal method using a mixed solution of zinc nitrate and ethanol. The reaction and growth mechanisms of ZnO twin-cones were investigated by X-ray diffraction, UV-visible spectra, infrared and ion trap mass spectra, and transmission electron microscopy. All as-prepared ZnO cones consisted of tiny single crystals with lengths of several micrometers. With prolonging of the reaction time from 1.5 h to 7 days, the twin-cone shape did not change at all, while the lattice parameters increased slightly and the emission peak of photoluminescence shifted from the green region to the near orange region. ZnO twin-cones are also explored as an additive to promote the thermal decomposition of ammonium perchlorate. The variations of photoluminescence spectra and catalytic roles in ammonium perchlorate decomposition were discussed in terms of the defect structure of ZnO twin-cones.

129 citations


Journal ArticleDOI
TL;DR: In this paper, the performance of nanometer copper ferrite on the thermal decomposition of ammonium perchlorate (AP) was investigated by DTA and the results showed that the nanometer CuFe 2 O 4 has high a catalytic activity, and the temperature of AP shift 105 ˚C downward with the effect of nano-copper ferrite.

124 citations



Journal ArticleDOI
TL;DR: In this article, the catalytic effect of two different sizes of a-Fe2O3 nanoparticles synthesized using an electrochemical method was investigated on the thermal decomposition of ammonium perchlorate (AP) using differential scanning calorimetry as a function of catalyst concentration.
Abstract: The catalytic effect of two different sizes of a-Fe2O3 nanoparticles synthesised using an electrochemicalmethod was investigated on the thermal decomposition of ammonium perchlorate (AP) using differentialscanning calorimetry as a function of catalyst concentration. The nanosized ferric oxide particles exhibitedmore of a catalytic effect on the thermal decomposition of AP than commercial Fe2O3 particles. A loweringof the high-temperature decomposition of AP by 59 oC was observed after mixing with 2 Wt per cent ofa-Fe2O3 particles with the very fine size of 3.5 nm. The mixture produced a high heat release of 4.574 kJ/g compared to 0.834 kJ/g of pure AP. The kinetic parameters were evaluated using Kissinger method. Thedecrease in the activation energy and increase in rate constant confirmed the catalytic activity of thesenanoparticles. Defence Science Journal, 2008, 58(6), pp.721 -727 , DOI:http://dx.doi.org/10.14429/dsj.58.1699

86 citations


Journal ArticleDOI
TL;DR: In this paper, X-ray diffraction, transition electron microscopy, thermogravimetry, Brunauer-Emmett-Teller technique, Fourier transform infrared spectroscopy, and Raman phonon modes were used.
Abstract: CuO nanocrystals of different surface areas were prepared. All samples were characterized by X-ray diffraction, transition electron microscope, thermogravimetry, Brunauer-Emmett-Teller technique, Fourier transform infrared spectroscopy, and Raman spectroscopy. CuO nanocrystals showed a stable monoclinic structure. With increasing surface areas, the surface hydration became significant, which is followed by shifts in infrared frequencies and Raman phonon modes. CuO nanocrystals were explored as an additive to catalytic decomposition of ammonium perchlorate (AP). AP decomposition underwent a two-stage process. Addition of CuO nanocrystals led to a downshift of high-temperature stage towards lower temperatures.

79 citations


01 Jan 2008
TL;DR: In this paper, the catalytic effect of two different sizes of a-Fe 2 O 3 nanoparticles synthesized using an electrochemical method was investigated on the thermal decomposition of ammonium perchlorate (AP) using differential scanning calorimetry as a function of catalyst concentration.
Abstract: The catalytic effect of two different sizes of a-Fe 2 O 3 nanoparticles synthesised using an electrochemical method was investigated on the thermal decomposition of ammonium perchlorate (AP) using differential scanning calorimetry as a function of catalyst concentration. The nanosized ferric oxide particles exhibited more of a catalytic effect on the thermal decomposition of AP than commercial Fe 2 O 3 particles. A lowering of the high-temperature decomposition of AP by 59 o C was observed after mixing with 2 Wt per cent of a-Fe 2 O 3 particles with the very fine size of 3.5 nm. The mixture produced a high heat release of 4.574 kJ/ g compared to 0.834 kJ/g of pure AP. The kinetic parameters were evaluated using Kissinger method. The decrease in the activation energy and increase in rate constant confirmed the catalytic activity of these nanoparticles.

72 citations


Journal ArticleDOI
TL;DR: In this paper, the effect of various concentrations of nitrate on perchlorate reduction was analyzed and determined whether perchlorates concentrations in the profile are toxic to the native microbial population.
Abstract: In the United States, perchlorate has been officially recognized as an environmental contaminant. In Israel, widespread perchlorate contamination has been found in the 40-m deep vadose zone near an ammonium perchlorate manufacturing plant north of Tel Aviv, above the central part of Israel's coastal aquifer, with peak concentrations of 1200 mg kgsediment−1. In this study, we examined the perchlorate-reduction potential by native microbial communities along this deep contaminated vadose zone profile. We analyzed the effect of various concentrations of nitrate on perchlorate reduction and determined whether perchlorate concentrations in the profile are toxic to the native microbial population. All experiments were performed in soil slurries with sediments taken from the contaminated site. Perchlorate was reduced to chloride in three (1, 15 and 35 m) of the four examined sediment samples taken from different depths (1, 15, 20, and 35 m below surface). No activity was observed in the sediment sample from 20 m below land surface, suggesting low viable microbial communities and water content, and high perchlorate concentrations. In the presence of nitrate, the lag time for perchlorate degradation was inversely correlated to nitrate concentration. We found no perchlorate degradation as long as nitrate was present in the system, and perchlorate degradation initiated only after all the nitrate had been reduced. Nitrate-reduction rates were correlated to the initial concentrations of nitrate and no lag period was observed for nitrate reduction. Viable microbial populations were observed at both high concentrations (10,000 mg l−1 and 20,000 mg l−1) and with no addition of perchlorate, at levels of 2.35 × 105, 4.01 × 105, and 3.41 × 103 CFU ml−1, respectively; these results were well correlated to those found by PCR amplification analysis of chlorite dismutase. We suggest that the microbial community has adapted to the conditions of high perchlorate concentrations in the unsaturated zone over 30 years of exposure. When no external carbon source was added to the slurry of soil from land surface, all perchlorate was removed after 134 days of incubation. The average perchlorate-reduction rate using natural organic matter as a carbon source was 0.45 mg day−1, while the average rate using acetate as an external carbon source was 7.2 mg day−1.

57 citations


Journal ArticleDOI
TL;DR: In this paper, single crystalline Ni nanoparticles with high purity have been prepared by a hydrogen plasma method and it is found that these nanoparticles have significant catalytic effect on the decomposition of ammonium perchlorate (AP).

50 citations


Journal ArticleDOI
TL;DR: In this paper, the catalytic activities of NiO nanocrystals on the thermal decomposition of ammonium perchlorate were investigated by thermogravimetric analysis (TG) coupled with differential thermal analysis (DTA).
Abstract: This work reported on the thermal decomposition of ammonium perchlorate activated by addition of NiO nanocrystals with different surface areas. NiO samples were characterized by X-ray diffraction (XRD), transition electron microscope (TEM), Brunauer-Emmett-Teller (BET) technique, Fourier transform infrared spectroscopy (FTIR), and Raman spectroscopy. With increasing annealing temperature, the surface areas of NiO samples reduced from 108.6 to 0.9 m2 g−1. The catalytic activities of NiO nanocrystals on the thermal decomposition of ammonium perchlorate were investigated by thermogravimetric analysis (TG) coupled with differential thermal analysis (DTA). With addition of NiO nanocrystals, thermal decomposition temperature of AP decreased greatly. Larger surface areas of NiO nanocrystals promoted the thermal decomposition of AP.

Journal ArticleDOI
TL;DR: In this article, Mg nanoparticles were prepared in tetrahydrofuran via lithium reduction of the corresponding Mg salt and X-ray diffraction and scanning electron microscope investigations confirm the formation of hexagonal phase Mg particles with an average size of 300 nm.

Journal ArticleDOI
TL;DR: The results shows that the p states for the two solids play a very important role in their chemical reaction, and ADN has more motion modes for the vibrational frequencies than AP from the low frequency to high frequency region.
Abstract: The electronic structure, vibrational properties, absorption spectra, and thermodynamic properties of crystalline ammonium perchlorate (AP) and ammonium dinitramide (ADN) have been comparatively studied using density functional theory in the local density approximation. The results shows that the p states for the two solids play a very important role in their chemical reaction. From the low frequency to high frequency region, ADN has more motion modes for the vibrational frequencies than AP. The absorption spectra of AP and ADN display a few, strong bands in the fundamental absorption region. The thermodynamic properties show that ADN is easier to decompose than AP as the temperature increases.

Journal ArticleDOI
TL;DR: In this paper, the catalytic effect of Co nanoparticles on the decomposition of ammonium perchlorate (AP) was investigated by differential thermal analyzer (DTA).

Journal ArticleDOI
TL;DR: In this article, the catalytic activities of the MTTMF nanocrystallites on thermal decomposition of ammonium perchlorate (AP) were investigated using thermogravimetric analysis (TG), differential scanning calorimetry (DSC), differential thermal analysis (DTA), and ignition delay measurements.

Journal ArticleDOI
TL;DR: A detailed study of the structural, electronic, and vibrational properties of crystalline ammonium perchlorate under hydrostatic compression was performed with density functional theory and shows that the interactions between electrons are strengthened under the influence of pressure.
Abstract: A detailed study of the structural, electronic, and vibrational properties of crystalline ammonium perchlorate (AP) under hydrostatic compression was performed with density functional theory. The results show that the compressibility of AP is nearly isotropic. Our calculated cell volumes under compression are in agreement with experimental data. As the pressure increases, the band gap of AP first increases, peaks, and then gradually decreases. An analysis of density of states shows that the interactions between electrons, especially for the valence electrons, are strengthened under the influence of pressure. The calculated vibrational frequencies under different pressures are in agreement with available experimental data. On the whole, the frequency increase is more pronounced in the low-pressure range compared to the high-pressure region, and furthermore, different vibrational modes show distinctly different pressure-dependent behaviors.

Journal ArticleDOI
TL;DR: In this paper, a row of progressively complicated ammonium-nitrate-based systems: ammonium nitrate/catalyst, ammonium perchlorate and Al to the binary mixture of a catalyzed ammonium Nitrate/binder yields a regular increase in the burning rate and a small change in the pressure exponent.
Abstract: DOI: 10.2514/1.35233 This paper discusses results obtained by studying a row of progressively complicated ammonium-nitrate-based systems: ammonium nitrate/catalyst, ammonium nitrate/catalyst/hydroxy terminated polybutadiene, ammonium nitrate/catalyst/hydroxy terminated polybutadiene/ammonium perchlorate, and ammonium nitrate/catalyst/ hydroxy terminated polybutadiene/ammonium perchlorate/Al. The successive addition of ammonium perchlorate and Al to the binary mixture of a catalyzed ammonium nitrate/binder yields a regular increase in the burning rate, accompanied by a small change in the pressure exponent. On the basis of flame-structure investigation by fine tungsten-rhenium thermocouples, it has been determined that the surface temperature of catalyzed ammonium nitrateaswellasammonium-nitrate-based propellantsiscontrolledbythedissociationreactionofthesaltoccurring at the surface. An analysis of the results obtained suggests a combustion mechanism of ammonium-nitrate-based propellants, which is based on the leading role of heat release in the condensed phase.

Journal ArticleDOI
TL;DR: In this paper, the effects of fullerenes including fellerene soot (FS), extracted fullerene SOot (EFS) and pure C60 on the thermal decomposition of ammonium perchlorate (AP) compared with traditional carbon black (CB) catalyst has been studied by employing thermogravimetry (TG), differential thermal analysis (DTA), infrared spectroscopy (IR) and ignition temperature experiments.
Abstract: The effects of fullerenes, including fellerene soot (FS), extracted fullerene soot (EFS) and pure C60 on the thermal decomposition of ammonium perchlorate (AP) compared with traditional carbon black (CB) catalyst has been studied by employing thermogravimetry (TG), differential thermal analysis (DTA), infrared spectroscopy (IR) and ignition temperature experiments. The results showed that the addition of CB and FS to AP reduced the activation energy as well as the temperature at maximum decomposition rate, but that of EFS and pure C60 had little effect on the thermal decomposition of AP, and among all catalysts, FS was the best one.

Journal ArticleDOI
TL;DR: In this article, the burning rate of bimodal ammonium perchlorate-based composite propellant is investigated, and the combustion characteristics of the coarse particles and the fill region are investigated.
Abstract: It is well known that the burning rate of the ammonium perchlorate-based composite propellant depends on the mean particle diameter of ammonium perchlorate. Recently, it was reported that the packing fraction of ammonium perchlorate in the propellant matrix influences the burning rate. The mean particle diameter of the bimodal ammonium perchlorate system decreases by increasing the fine ammonium perchlorate content, and the packing fraction is a maximum when the coarse ammonium perchlorate content is approximately 0.8. The detailed experimental data on the burning rate characteristics of the propellants with bimodal ammonium perchlorate systems were investigated in this study. The burning rates of the ammonium perchlorate-based propellants at a constant mean diameter would not be identical when the packing fractions of the ammonium perchlorate particles were not constant. The burning rate of the bimodal ammonium perchlorate propellant is influenced not only by the mean particle diameter of the ammonium perchlorate, but also by the coarse ammonium perchlorate content and the diameter ratio of the coarse ammonium perchlorate to the fine ammonium perchlorate. The coarse ammonium perchlorate particles play an important role in the combustion of the bimodal ammonium perchlorate propellant even when the coarse particles are loosely dispersed in the fill region consisting of the fine particles and hydroxyl terminated polybutadiene. The combustion characteristics of the coarse ammonium perchlorate particles and the fill region would be the dominant factors influencing the burning rate of the bimodal ammonium perchlorate propellant.

01 Jan 2008
TL;DR: In terms of publications, ammonium perchlorate (AP) has been the most extensively investigated solid oxidizer since its introduction into propellants, probably in the late 1940s by the Jet Propulsion Laboratory as discussed by the authors.
Abstract: W ORLDWIDE, ammonium perchlorate (AP, NH^CIC^) and hydroxylterminated-polybutadiene (HTPB) composite mixtures, usually also containing aluminum powder and ballistic modifiers, are the most frequently used formulations in solid rocket propellants. In terms of publications, AP has been the most extensively investigated solid oxidizer since its introduction into propellants, probably in the late 1940s by the Jet Propulsion Laboratory. A large number of publications appeared in 1950-1970, and, by comparison, a relatively lesser number have appeared since then. The impressive review by Jacobs and Whitehead was quite extensive in range and depth at the time of publication in 1969. The falloff in research interest after this time is reflected in the additional information reviewed 10-15 years later, but subsequent reviews of various aspects of decomposition, ignition, and combustion" of AP-composite propellants have appeared. A modest resurgence of new interest in AP-composite propellant decomposition and combustion is motivated in part by the availability of advanced methods of diagnostics," by new kinetics data and methods of modeling," and by intriguing plateau-burning behavior of some AP-HTPB formulations.' Despite the widespread use and long investigative history of AP-fuel mixtures, it still can be said that AP alone and AP-fuel composites remain among the most confounding materials in the research setting. From the point of view of chemistry, one reason is that the full range of formal oxidation states of nitrogen and chlorine can apparently become involved, for example, the formal oxidation state of Cl in C1O4 is +7, whereas that of HC1 is -1; N in NHj is -3, whereas that of N in NOj (Ref. 19) and HNO3 (Ref. 20) is +5. When all of the various combinations of

Journal ArticleDOI
01 May 2008-Fuel
TL;DR: In this paper, an experimental study was conducted to evaluate the ignitibility of a family of potential gas-generator solid propellants under different CO 2 laser heat fluxes and chamber operating conditions.

Journal ArticleDOI
TL;DR: In this article, the catalytic activity of mixed valent manganese oxide octahedral molecular sieve (OMS) on the thermal decomposition of ammonium perchlorate (AP) has been briefly studied.

Journal ArticleDOI
TL;DR: Experimental data on comparative study indicate that the compositions containing aluminium and ammonium perchlorate are superior to propellant NQ in respect of energy.

Journal ArticleDOI
TL;DR: In this article, an ammonium perchlorate (AP) with different morphologies was synthesized by the polymer-assisted crystal-habit modification route using poly(vinyl alcohol) and AP salt solutions were prepared and mixed in different proportions.
Abstract: One of the key aspects in the development of new inorganic materials is the synthesis of particles with specific sizes and morphologies. Nowadays, water-soluble polymers as crystal-growth modifiers are gaining more importance in the field of morphogenesis of inorganic crystals. Ammonium perchlorate (AP) is an extensively used solid propellant oxidizer. Oxidizer particles with a particular morphology are a challenging requirement in the propellant field. In the present study, AP with different morphologies was synthesized by the polymer-assisted crystal-habit modification route. Poly(vinyl alcohol) and AP salt solutions were prepared and mixed in different proportions. Samples were drawn from the mixture, dried on glass slides, and analyzed by scanning electron microscopy and powder X-ray diffraction (PXRD). AP crystals with a rectangular prism and a rectangular wedge shape were obtained, and the reasons for their shapes are discussed. The PXRD patterns showed that the phase of AP obtained is the same as t...

Journal ArticleDOI
TL;DR: In this paper, the catalytic effect of Zn nanopowders on the thermal decomposition of ammonium perchlorate (AP) and those of zn nano-drone powders was investigated using differential thermal analysis (DTA).
Abstract: In this paper, the catalytic effect of Zn nanopowders on thermal decomposition of ammonium perchlorate (AP) as well as those of Zn micropowders has been investigated using differential thermal analysis (DTA). The results show that both nanometer and micrometer Zn powders show similar excellent catalytic effect on the decomposition of AP, while the total heat releases of AP added by Zn nanopowders are generally higher than those of AP added by Zn micropowders. In addition, an attempt has been made to explain the observed results with the help of theoretical considerations and data generated during this work.

Journal ArticleDOI
TL;DR: In this paper, the authors describe experimental work on laser-assisted combustion and its use to control solid propellants, including ignition and interruption by laser irradiation, with a custom-made (fuel-rich) non-self-combustible solid propellant with a burning rate coincident with Vieille's law and a pressure exponent of approximately 0.5.
Abstract: This paper describes experimental work on laser-assisted combustion and its use to control solid propellants. Burning rates of hydroxyl-terminated polybutadiene and ammonium perchlorate composite solid propellants were measured at pressures up to 90 kPa under laser irradiation, and propellant-preheat temperature distribution was measured by thermography. Combustion control, including ignition and interruption by laser irradiation, was feasible with custom-made (fuel-rich) non-self-combustible solid propellants with a burning rate coincident with Vieille's law and a pressure exponent of approximately 0.5. Consequently, this combustion-control concept seems to be applicable to a microsatellite thruster. The heat balance on the burning surface evaluated at a laser power density of 1.4 W ·mm -2 at 50 kPa produced the following results: chemical reaction was endothermic at a heat flux of -0.7W mm -2 , heat was supplied to the solid phase of the propellant at a heat flux of 3.7 W ·mm -2 , and heat-feedback rate to the burning surface was 3.0 W ·mm -2 , which suggests that approximately 70% of the energy transferred to the burning surface was provided by combustion itself, and the laser supplied supplementary heat flux to compensate for the heat insufficiency to sustain combustion.

Journal ArticleDOI
TL;DR: In this article, the authors presented a computational investigation on the deflagration of composite ammonium-perchlorate-based propellant with fine/ultrafine aluminum, based on an Eulerian representation of the particle cloud formed by the ejected aluminum and a gray medium approximation of the radiative field supported by the emitting particles.
Abstract: This paper presents a computational investigation on the deflagration of composite ammonium-perchlorate-based propellant with fine/ultrafine aluminum. The model relies on an Eulerian representation of the particle cloud formed by the ejected aluminum and a gray-medium approximation of the radiative field supported by the emitting particles. The aluminum oxidation is modeled by means of an experimentally evaluated diameter power law valid for constant-ambient conditions. The energetic consequences of the addition of nanoscale aluminum are analyzed, with particular emphasis on the contributions of radiative transport and aluminum oxidation heat release. The model is validated versus experimental measurements of burn rates for both one-dimensionally (fine ammonium perchlorate) and three-dimensionally (monomodal and bimodal coarse ammonium perchlorate) supported combustion fields. The burn rate and surface shape of two-dimensional laminate propellant is also considered, and the particle consumption time is related to experimental observations.

Journal ArticleDOI
TL;DR: In this article, the burning rate trends of both pure binder sandwiches and those containing a mixture of binder with fine ammonium perchlorate particles are investigated over appreciable ranges of pressure and thickness of the middle lamina in the sandwich.

Journal ArticleDOI
TL;DR: The combined kinetic and spectroscopic results are consistent with a proton-transfer reaction as the first decomposition step in shocked AP.
Abstract: Time-resolved Raman scattering measurements were performed on ammonium perchlorate (AP) single crystals under stepwise shock loading. For particular temperature and pressure conditions, the intensity of the Raman spectra in shocked AP decayed exponentially with time. This decay is attributed to shock-induced chemical decomposition in AP. A series of shock experiments, reaching peak stresses from 10-18 GPa, demonstrated that higher stresses inhibit decomposition while higher temperatures promote it. No orientation dependence was found when AP crystals were shocked normal to the (210) and (001) crystallographic planes. VISAR (velocity interferometer system for any reflector) particle velocity measurements and time-resolved optical extinction measurements carried out to verify these observations are consistent with the Raman data. The combined kinetic and spectroscopic results are consistent with a proton-transfer reaction as the first decomposition step in shocked AP.

Book ChapterDOI
21 Jul 2008
TL;DR: In this paper, the thermal decomposition of aged and non-aged samples of ammonium perchlorate (AP)/hydroxyl-terminated-polybutadiene (HTPB), the AP/HTPB solid propellant, were studied at different heating rates in dynamic nitrogen atmosphere.
Abstract: The thermal decomposition of aged and non-aged samples of ammonium perchlorate(AP)/hydroxyl-terminated-polybutadiene(HTPB), the AP/HTPB solid propellant, were studied at different heating rates in dynamic nitrogen atmosphere. The exothermic reaction kinetics was studied by differential scanning calorimetry (DSC) in non-isothermal conditions. The Arrhenius parameters were estimated according to the Ozawa method. The calculated activation energies were 134.5 kJ/mol (non-aged) and 79.0 kJ mol -1 (aged), the pre-exponential factors, A, were 2.04 10 10 min -1 for the non-aged samples and 1.29.10 6 min -1 for the aged samples and the reaction orders for the global composite decomposition were estimated in 0.7 and 0.6 (non-aged and aged samples decomposition, respectively) by the kinetic Shimadzu software based in the Ozawa method. The Kissinger method for obtaining the activation energy value was also used for a comparison purpose. These results are here discussed.