Results of DTA‐TG investigation and chemical analysis of electro‐exploded aluminum nanopowders, passivated and/or coated with the non‐inert reagents: nitrocellulose (NC), oleic acid (C17H33COOH) and stearic acid (C17H35COOH), which were suspended in kerosene and ethanol, amorphous boron, nickel, fluoropolymer, ethanol and air (for comparison), are discussed. Surface protection of aluminum nanopowders by coatings of different origin results in significant advantages in the energetic properties of the powders. Aluminum nanopowders with a protecting surface show increased stability to oxidation in nitrogen, air and in water during storage period. On the basis of the experimental results, a diagram of the formation and stabilization of the coatings is proposed. The kinetics of the interaction of aluminum nanopowders with nitrogen, air and water is discussed. Recommendations concerning the efficiency of non‐inert reagent passivation are proposed on the basis of comprehensive analysis of the experimental data.
In this study HMX was recrystallized from different solvents by a cooling crystallization process to improve the product quality and to produce a more insensitive product. It was found that particles with the best quality were crystallized from propylenecarbonate with a nucleation initiation by dosing a small amount of water as drowning‐out substance. This leads to particles with a very high density (near to the theoretical value) and thus to particles with a small amount of inclusions. GAP tests with this product show less sensitivity against shock. A clear linear dependence of the particle density on the shock initiation pressure was found. The particle density is relatively easy to measure so it will be a useful measure to determine the sensitivity of the material.
Outre l'analyse de l'in¯uence des divers parame Átres du proce Âde  tels que les taux de dispersion, la puissance applique Âe, le temps de mise en e Âmulsion, on e Âtudie l'in¯uence des agents e Âmulsi-®ants et le comportment rhe Âologique de la phase continue. Au cours de la deuxie Áme e Âtape du proce Âde Â, la cristallisation des gouttes d'ADN en particules solides sphe Âriques est obtenue par refroidissement du syste Áme. Cette me Âthode de cristallisation en e Âmulsion permet de produire des particules d'ammonium dinitramide de granulome Âtrie moyenne situe  entre 10 et 600 mm. La qualite  de l'ADN rescristallise Â, ainsi obtenu, discute Âe dans cet article, a e Âte  de Âtermine Âe a  l'aide de diffe Âr-entes me Âthodes d'analyse telles que la calorime Âtrie diffe Ârentielle dynamique (DSC), la spectroscopie IR, la chromatographie ionique et la spectrome Âtrie a Á diffraction laser.
SummaryThe described process aims to produce spherical ammonium dinitramide (ADN) particles of different sizes with a narrow particle size distribution. The crystallization process presented in this paper consists of two stages. In the ®rst stage, molten ADN is dispersed in a continuous phase in which ADN is insoluble. The droplet size produced can be controlled by varying the amount of mechanical energy supplied to the two-phase system. In addition to discussing the in¯u-ence of the different process parameters, such as dispersion rate, dispersion power, emulsi®cation time etc. this paper also reports the in¯uence of emulsifying agents and the rheological behavior of the continuous phase. In the second stage of the process, crystallization of the emulsi®ed ADN droplets to spherical, solid particles is obtained by reducing the temperature of the system. The process described enables production of spherical ammonium dinitramide particles with mean sizes from 10 mm to 600 mm. The product quality of the crystallized ADN, which is also discussed in this paper, was determined using various analysis techniques, including differential scanning calorimetry (DSC), IR spectroscopy, ion chromatography and laser light diffraction spectrometry.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.