In situ synthesis of cobalt alginate/ammonium perchlorate composite and its low temperature decomposition performance

Electrochemical Synthesis of the Energetic Combustion Catalyst Co(BODN)·9H2O and Its Catalytic Effect on Ammonium Perchlorate Thermal Decomposition

Safe, efficient, and green synthetic energetic combustion catalysts are of great importance for the application of ammonium perchlorate (AP) in solid propellants. In this study, a novel, simple, efficient, and green electrochemical method for synthesizing energetic combustion catalysts was designed and implemented to successfully synthesize Co(BODN)·9H2O (BODN = [2,2'-bi{1,3,4-oxadiazole}]-5,5'-dinitramide), a novel energetic combustion catalyst. The target products were characterized via single-crystal X-ray diffraction, powder X-ray diffraction, Fourier transform infrared spectroscopy, optical microscopy, scanning electron microscopy, differential scanning calorimetry, and thermogravimetric analysis. Results reveal that Co(BODN)·9H2O crystallizes in the triclinic P1̅ space group and has a density of 1.836 g cm-3. The size of the Co(BODN)·9H2O crystal increases gradually with the increase in the reaction current and the prolongation of the reaction time, respectively. However, the change in reaction current and time does not affect the crystal form. In addition, with the increase in Co(BODN)·9H2O content, the peak temperature of high-temperature decomposition (HTD) and apparent activation energy of AP/Co(BODN)·9H2O gradually decrease, and the heat release during thermal decomposition gradually increases. The HTD peak temperature and apparent activation energy of AP/Co(BODN) 9H2O (10%) decrease by 97.9 °C and 94.2 kJ·mol-1, respectively, compared with those of pure AP, and the heat release during thermal decomposition increases by 1613 J·g-1. Furthermore, compared with those of the propellant containing pure AP, the burning rate and flame temperature of the propellant containing AP/Co(BODN)·9H2O (10%) increase by 8.15 mm s-1 and 458.44 °C, respectively. Real-time Fourier transform infrared spectroscopy reveals that CoO catalyzes the thermal decomposition of AP mainly by promoting electron transfer to accelerate the oxidation of NH3 and the conversion of N2O to NO. In brief, this work provides new insights into synthesizing energetic combustion catalysts. Moreover, Co(BODN)·9H2O synthesized through the electrochemical method exhibits considerable application prospects for improving the thermal and energy performance of AP and the combustion performance of propellants.

Gelatin-modified Mxene carbon aerogels for ammonium-perchlorate-catalyzed thermal decomposition

The assembly of 2D Ti3C2Tx nanosheets into 3D structures with orderable structure has great importance for their use as catalyst carriers. However, Ti3C2Tx nanosheets are prone to accumulate in aqueous solutions owing to the strong van der Waals forces between Ti3C2Tx nanosheet layers, degrading their chemical properties. Carbon aerogel (Ti3C2Tx/G/Co) with a 3D porous structure and cobalt as the active site was prepared by a simple co-assembly-freeze-drying-high-temperature carbonization method for application in catalysis of ammonium perchlorate.

Prism-like bimetallic (Ni-Co) alkaline carboxylate-based non-enzymatic sensor capable of exceptionally high catalytic activity towards glucose

In this study, we fabricated a novel non-enzymatic glucose sensor based on prism-like bimetallic alkaline carboxylate (CoNi-MIM). The morphology and structure of CoNi-MIM were carefully investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM), powder X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The electrochemical glucose oxidation of the synthesized sensor was then explored by cyclic voltammetry (CV) and chronoamperometry in alkaline medium. It was found that CoNi-MIM is the optimal choice with a remarkably high sensitivity of 5024.4 μA mM^-1 cm^-2, low detection limit of 56.1 nM (S/N = 3), linear response of up to 14.3 mM and excellent selectivity compared to Co-MIM, CoFe-MIM and CoMn-MIM. Furthermore, the as-fabricated sensor demonstrated appreciable practicality for the determination of glucose in real samples. These results indicate that CoNi-MIM holds a good application prospect in non-enzymatic glucose sensing.

Significantly Enhanced Thermal Decomposition of Mechanically Activated Ammonium Perchlorate Coupling with Nano Copper Chromite

In this article, nano-CuCr₂O₄ (copper chromite)/ultrafine ammonium perchlorate (AP) composites were prepared by a ultrasonic dispersion method and a mechanical grinding method. A series of nano-CuCr₂O₄/ultrafine AP composites with different dispersions were prepared by controlling the compounding time to study the best catalytic effect of nano-CuCr₂O₄ on the ultrafine AP. The microstructures, surface elements, and morphologies of samples were analyzed by X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, and energy dispersion X-ray spectroscopy. The catalytic effect of nano-CuCr₂O₄ on the thermal decomposition of AP was investigated by differential scanning calorimetric techniques and thermogravimetric analysis. The results indicated that the mechanical ball milling method could make nano-CuCr₂O₄ more evenly dispersed on the ultrafine AP, and with the increase in the milling time, the uniformity of nano-CuCr₂O₄ on the ultrafine AP was better. When the milling time was 6-12 h, nano-CuCr₂O₄ was most evenly dispersed on the ultrafine AP. At this time, the decomposition temperature and Gibbs free energy of the nano-CuCr₂O₄/ultrafine AP composite were the lowest, which decreased by 78.1 °C and 25.16 kJ/mol compared with those of ultrafine AP, respectively. Moreover, the mechanical sensitivity of nano-CuCr₂O₄/ultrafine AP composites was lower than that of ultrafine AP. It showed that ball milling for 6-12 h could make nano-CuCr₂O₄ evenly dispersed on the ultrafine AP, and nano-CuCr₂O₄ could play the best catalytic effect on the ultrafine AP.

Improving safety and thermal decomposition performance by the in situ synthesis of core–shell structured ammonium perchlorate/cobalt acetate hydroxide composites

The AP/Co₃(CH₃COO)₅(OH) composites of the core–shell structure were prepared, the safety and thermal decomposition properties of AP were improved simultaneously, and the possible catalytic mechanism was analyzed.

Interpol review of detection and characterization of explosives and explosives residues 2016-2019

This review paper covers the forensic-relevant literature for the analysis and detection of explosives and explosives residues from 2016-2019 as a part of the 19th Interpol International Forensic Science Managers Symposium. The review papers are also available at the Interpol website at: https://www.interpol.int/Resources/Documents#Publications.

Porous Cr2O3 bead with a 3D continuous pore architecture: synthesis and its catalytic performance for decomposition of ammonium perchlorate

Mesoporous/macroporous Cr₂O₃ beads with 3D continuous pore structure exhibit improved thermal decomposition of ammonium perchlorate compared with Cr₂O₃ crystals.

In situ synthesis of hydrophobic coatings: an effective strategy to reduce hygroscopicity and catalyze decomposition of ammonium perchlorate

An in situ reaction of stearic acid with copper acetate or cobalt acetate was adopted to prepare hydrophobic coatings, which effectively reduced the hygroscopicity and accelerated the thermal decomposition process of ammonium perchlorate.