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The dissolution properties of 2-oxo-1,3,5-trinitro-1,3,5-triazacyclohexane (Keto-RDX) in dimethyl sulfoxide (DMSO) were studied by using a RD496-2000 Calvet microcalorimeter at four different temperatures under atmospheric pressure. The heat effects, molar enthalpies (ΔdissH), and differential enthalpies (ΔdifH) of dissolution were determined. Furthermore, the corresponding kinetic equations describing the dissolution processes at the four experimental temperatures are dα/dt = 10−2.43 (1 − α)0.63 (T = 298.15 K), dα/dt = 10−2.41 (1 − α)0.67 (T = 303.15 K), dα/dt = 10−2.40 (1 − α)0.75 (T = 308.15 K), and dα/dt = 10−2.38 (1 − α)0.76 (T = 313.15 K). The determined values of the activation energy E and pre-exponential factor A for the dissolution process are 5.99 kJ mol−1 and 10−1.38 s−1, respectively. [ABSTRACT FROM AUTHOR]

• Porous plate-like Li2ZnTi3O8 was prepared in a low energy consumption method. • The nanostructure formation mechanism was analyzed in detail. • The kinetics properties was enhanced due to the advanced microstructure. • Enhanced Li+ storage with a mass of pseudocapacitance was achieved. • Its reversible capacity exceeds all current reports of LZTO-based anodes. Spinel Li 2 ZnTi 3 O 8 (LZTO) is widely studied in the field of anode materials for lithium-ion batteries (LIBs) in recent years because of its stable cycling performance, no volume expansion and higher theoretical capacity than that of Li 4 Ti 5 O 12. In this work, porous plate-like LZTO is synthesized via a simple in situ topological reaction with layered Titanic acid as the precursor. Due to its special morphology, a large amount of pseudocapacitance is introduced for lithium-ion storage in conjunction with the intercalation reaction. This co-storage mode allows more Li+ to be stored, resulting in the plate-like LZTO getting the highest capacity in the LZTO-based anode. It shows a reversible capacity of 338 mAh/g at 0.1 A/g and maintains excellent performance in long cycle tests under high current density (208 mAh/g after 1000 cycles at 1 A/g and 118 mAh/g after 2000 cycles at 5 A/g). In terms of electrochemical reaction kinetics, the two-dimensional plate structure provides a flat path for electron transport and the micropores on its surface provide many fast channels for the Li+ diffusion. Its simple synthesis method and excellent electrochemical properties prove that it has a great potential to become the new generation of anode materials for LIBs. [Display omitted] [ABSTRACT FROM AUTHOR]

A new nitrogen-rich energetic material, hydrazinium 3,5-dinitroamino-1,2,4-triazole (HDNAT), was synthesized. Thermal behavior and non-isothermal decomposition kinetics of HDNAT were studied with DSC and TG/DTG methods. The non-isothermal decomposition kinetic equation is $$\frac{{{\text{d}}\alpha }}{{{\text{d}}T}} = \frac{{10^{19.37} }}{\beta }6(1 - \alpha )^{{{2 \mathord{\left/ {\vphantom {2 3}} \right. \kern-0pt} 3}}} [1 - (1 - \alpha )^{{{1 \mathord{\left/ {\vphantom {1 3}} \right. \kern-0pt} 3}}} ]^{{{1 \mathord{\left/ {\vphantom {1 2}} \right. \kern-0pt} 2}}} \exp ( - 188.6 \times 10^{3} /RT)$$ . Self-accelerating decomposition temperature and critical temperature of thermal explosion of HDNAT are 168.1 and 178.1 °C, respectively. Specific heat capacity of HDNAT was determined with a micro-DSC method and the molar heat capacity is 258.96 J mol K at 298.15 K. Adiabatic time-to-explosion of HDNAT is about 100 s. The impact sensitivity, friction sensitivity, detonation velocity and detonation pressure of HDNAT are >13.1 J, 84 %, 9.0 km s and 36.0 GPa, respectively. [ABSTRACT FROM AUTHOR]

The effects of nano-CuO particles on thermal decomposition behavior of the copolymer of 3,3′-bis(azidomethy) oxetane and glycidyl azide polymer (BAMO–GAP) were investigated by employing DSC–TG–FTIR–MS coupling technique. The results showed that, when the nano-CuO was dispersed into the BAMO–GAP copolymer, the thermal decomposition temperatures of copolymer was decreased, the apparent activation energy was decreased by 11.2 kJ mol −1 and the apparent decomposition heat increased by maximum 12%. The major gaseous products of BAMO–GAP copolymer and BAMO–GAP/CuO were identified. It was suggested that nano-CuO enhanced the N N bond breaking in azido groups and more N 2 was released. Namely, nano-CuO is a marked kind of catalyst, which has a crucial effect on thermal decomposition of BAMO–GAP copolymer. [ABSTRACT FROM AUTHOR]

The dissolution properties of ammonium dinitramide (ADN) in N-methyl pyrrolidone (NMP) were studied with a RD496-2000 Calvet microcalorimeter at four different temperatures under atmospheric pressure. The heat effects were determined for ADN in NMP. The molar enthalpies and the differential molar enthalpies for ADN in NMP were also obtained at the same time. The corresponding kinetic equations that describe the four dissolution processes are discussed. [ABSTRACT FROM AUTHOR]

A new energetic zinc-FOX-7 complex, Zn(NH)(FOX-7) (FOX-7 = 1,1-diamino-2,2-dinitroethylene), was first synthesized. Thermal decomposition behavior and nonisothermal decomposition kinetics of Zn(NH)(FOX-7) were studied with DSC and TG/DTG methods. The kinetic equation obtained is $$ \frac{{{\text{d}}\alpha }}{{{\text{d}}T}} = \frac{{10^{13.99} }}{\beta }4(1 - \alpha )[ - \ln (1 - \alpha )]^{{{3 \mathord{\left/ {\vphantom {3 4}} \right. \kern-0pt} 4}}} \exp ( - 1.448 \times 10^{5} /RT) $$ . The self-accelerating decomposition temperature ( T) and critical temperature of thermal explosion ( T) are 183.2 and 195.8 °C, respectively. The specific-heat capacity of Zn(NH)(FOX-7) was determined with a micro-DSC method, and the molar-heat capacity is 454.6 J mol K at 298.15 K. Adiabatic time-to-explosion was also estimated to be about 20 s. The thermal stability of Zn(NH)(FOX-7) is good and higher than that of analogous Cu(NH)(FOX-7). [ABSTRACT FROM AUTHOR]

The high nitrogen compound 3,6-bis(1H-1,2,3,4-tetrazol-5-yl-amino)-1,2,4,5-tetrazine and the high energy density material hexanitrohexaazaisowurtzitane (HNIW), were used as substitute of hexogen (RDX) in the composite modified double base (CMDB) propellant formulations, the propellant samples were prepared, the thermal behaviors, nonisothermal reaction kinetics, and thermal safety were carried out, and the eight important parameters were calculated and obtained as the self-accelerating decomposition temperature ( T), thermal ignition temperature ( T), critical temperatures of thermal explosion ( T), critical temperature of hot-spot initiation ( T), characteristic drop height of impact sensitivity ( H), critical thermal explosion ambient temperature ( T), safety degree ( S), and thermal explosion probability ( P). It shows that the content of HNIW has a large effect on the decomposition reaction mechanism of the CMDB propellant, when the content of HNIW is 10 %, the decomposition reaction are controlled by the random nucleation and subsequent growth ( n = l), and the reaction mechanism obeys Mampel law; but when the content of HNIW is 20 %, the decomposition reaction are controlled by the chemical reaction ( n = 1/4). The mechanism can not be changed by the catalysts, and they just make the apparent activation energy change slightly. For the sample, from BC01 to BC04, the values of T and T making an upward tendency, show the resistivity to heat: BC04 > BC03 > BC02 > BC01; the values of T and S, BC01 are the maximum and BC02 are the minimum, show the heat sensitivity: BC01 > BC03 > BC04 > BC02. For the same radius, the thermal safety of the sphere sample is greater than that of the infinite cylinder one. [ABSTRACT FROM AUTHOR]

The thermal decomposition behavior of composite modified double-base propellant containing hexanitrohexaazaisowurtzitane (CL-20/CMDB propellant) was studied by microcalorimetry. The kinetic and thermodynamic parameters were obtained from the analysis of the heat flow curves. The effect of different proportion of CL-20 to the thermal decomposition behavior, kinetics, and thermal hazard was investigated at the same time. The critical temperature of thermal explosion ( T), the self acceleration decomposition temperature ( T), and the adiabatic decomposition temperature rise (Δ T) were calculated to evaluate the thermal hazard of the CL-20/CMDB propellant. It shows that the CMDB propellant with 38% CL-20 has relative lower values of E and lg A, and with 18% CL-20 has the highest potential hazard. [ABSTRACT FROM AUTHOR]

Abstract: The enthalpies of dissolution for ammonium dipicrylamide (ADPA) in dimethyl sulfoxide (DMSO) and N-methyl pyrrolidone (NMP) were measured using a RD496-2000 Calvet microcalorimeter at 298.15K under atmospheric pressure. Empirical formulae for the calculation of the enthalpies of dissolution (Δdiss H) were obtained from the experimental data of the dissolution processes of ADPA in DMSO and NMP. The linear relationships between the rate (k) and the molality (b) were found. The corresponding kinetic equations describing the two dissolution processes were for the dissolution of ADPA in DMSO, and for the dissolution of ADPA in NMP, respectively. [Copyright &y& Elsevier]

ABSTRACT Safflower seed oil rich in linoleic acid is a kind of functional health oil. The effects of various parameters, such as solvents, liquid-solid ratio and extraction time, on both ultrasonic-aided and conventional safflower seed oil extractions were investigated through experiments. The results indicated that n-hexane was a better solvent for the two above-mentioned extraction methods. Under the following conditions: temperature 35C, liquid-solid ratio 5, extraction time 30 min and ultrasound power 300 W, the oil extraction yield reached 27.02%. However, with the conventional safflower seed oil extraction method, it was only 25.00% when the technical parameters were: temperature 50C; liquid-solid ratio 6; extraction time 60 min. Obviously, the advantages of ultrasonic extraction were as follows: reducing extraction temperature; decreasing solvent quantity; saving time; and improving oil yield. In addition, on the basis of Fick's first law, the kinetic models of ultrasonic extraction and conventional extraction were compared and authenticated. The results showed that a close match was found between experimental data and kinetic equations, and the equations could better simulate safflower oil extraction process. This approach provided a theoretical background for the extraction of safflower seed oil. PRACTICAL APPLICATIONS In this work, an efficient extraction method - ultrasound-aided extraction method for safflower seed oil - was acquired. Compared with conventional extraction method, the advantages of ultrasonic extraction were: reducing extraction temperature, decreasing solvent quantity, saving time and improving oil yield. In addition, equipments used in ultrasound-aided extraction and operation were simple and high efficiency. Therefore, this ultrasonic technology has a brilliant application prospect in extraction of safflower seed oil and other vegetable oils. [ABSTRACT FROM AUTHOR]

Abstract: The composite modified double base (CMDB) propellants (nos. RB0601 and RB0602) containing 3,6-bis (1H-1,2,3,4-tetrazol-5-yl-amino)-1,2,4,5-tetrazine (BTATz) without and with the ballistic modifier were prepared and their thermal behaviors, nonisothermal decomposition reaction kinetics, thermal safety and burning rates were investigated. The results show that there are three mass-loss stages in TG curve and two exothermic peaks in DSC curve for the BTATz-CMDB propellant. The first two mass-loss stages occur in succession and the temperature ranges are near apart, and the decomposition peaks of the two stages overlap each other, inducing only one visible exothermic peak appear in DSC curve during 350–550K. The reaction mechanisms of the main exothermal decomposition processes of RB0601 and RB0602 are all classified as chemical reaction, the mechanism functions are f(α)=(1− α)2, and the kinetic equations are and . The thermal safety evaluation on the BTATz-CMDB propellants was obtained. With the substitution of 26% RDX by BTATz and with the help of the ballistic modifier in the CMDB propellant formulation, the burning rate can be improved by 89.0% at 8MPa and 47.1% at 22MPa, the pressure exponent can be reduced to 0.353 at 14–20MPa. [Copyright &y& Elsevier]

Abstract: The constant-volume combustion energy, (DNTF, s, 298.15K) and kinetic behavior of the exothermic decomposition reaction of the title compound (DNTF) are determined by a precise rotating bomb calorimeter and DSC, respectively. Its standard enthalpy of combustion, (DNTF, s, 298.15K), standard enthalpy of formation, (DNTF, s, 298.15K) and kinetic parameters of the major exothermic decomposition reaction in a temperature-programmed mode [the apparent activation energy (Ea) and pre-exponential factor (A)] are calculated. The values of (DNTF, s, 298.15K), (DNTF, s, 298.15K), and (DNTF, s, 298.15K) of DNTF are -9733.96 ± 8.59Jg-1, -3018.29 ± 2.68kJmol-1, and 657.23 ± 2.70kJmol-1, respectively. The kinetic model function in integral form and the value of Ea and A of the major exothermic decomposition reaction of DNTF are , 177.03kJmol-1 and 1013.68s-1, respectively. The critical temperature of thermal explosion of DNTF is 240.6°C. [Copyright &y& Elsevier]

The illegal use and low biodegradability of psychoactive substances has led to their introduction to the natural water environment, causing potential harm to ecosystems and human health. This paper compared the reaction kinetics and degradation mechanisms of ketamine (KET) and methamphetamine (METH) by UV/H2O2. Results indicated that the degradation of KET and METH using UV or H2O2 alone was negligible. UV/H2O2 had a strong synergizing effect, which could effectively remove 99% of KET and METH (100 μg/L) within 120 and 60 min, respectively. Their degradation was fully consistent with pseudo-first-order reaction kinetics (R2 > 0.99). Based on competition kinetics, the rate constants of the hydroxyl radical with KET and METH were calculated to be 4.43 × 109 and 7.91 × 109 M−1·s−1, respectively. The apparent rate constants of KET and METH increased respectively from 0.001 to 0.027 and 0.049 min−1 with the initial H2O2 dosage ranging from 0 to 1000 μM at pH 7. Their degradation was significantly inhibited by HCO3−, Cl−, NO3− and humic acid, with Cl− having relatively little effect on the degradation of KET. Ultraperformance liquid chromatography with tandem mass spectrometry was used to identify the reaction intermediates, based on which the possible degradation pathways were proposed. These promising results clearly demonstrated the potential of the UV/H2O2 process for the effective removal of KET and METH from contaminated wastewater. [ABSTRACT FROM AUTHOR]

Highlights: [•] The crystal structure of the new ionic compound DAT·DNBA was determinated and analyzed. [•] The thermal behavior and the decomposition reaction kinetics were investigated by means of DSC and RSFTIR. [•] Some parameters were calculated to evaluate the thermal stability and safety. [ABSTRACT FROM AUTHOR]

Abstract: The thermal behavior and decomposition kinetics of C4-bonded PBXs based on some attractive cyclic nitramines were investigated by means of nonisothermal TG and DSC techniques. It has been shown that only a single decomposition process has been observed for RDX-C4 while an obvious two-step process for mixture of BCHMX-C4 CL-20-C4, and HMX-C4. The onset temperature of the exotherms were observed at 216.3, 238.7, 279.2 and 236.7°C with the peak temperatures of 235.1, 279.0, 231.2 and 233.7°C for RDX-C4, BCHMX-C4, HMX-C4 and CL-20-C4, respectively. Their corresponding exothermic decompostion processes were covered by energy changes of 1749, 1938, 1213 and 2639Jg−1, which are lower than that of their pure cyclic nitramines. It was also proved that C4 matrix has significant effect on the activation energy distribution of RDX, BCHMX and CL-20, whose initial autocatalysis effect was inhibited or weakened. With regard to HMX-C4, the activation energy of its initial step is much lower than that of the second step. [Copyright &y& Elsevier]

Abstract: The enthalpy of dissolution of 1,1-diamino-2,2-dinitroethylene (FOX-7) in DMSO was measured by means of a RD496-2000 Calvet microcalorimeter at 298.15K. Empirical formulae for the calculation of the enthalpy of dissolution (Δdiss H), relative partial molar enthalpy (Δdiss H partial) and relative apparent molar enthalpy (Δdiss H apparent) were obtained from the experimental data of the enthalpies of dissolution of FOX-7 in dimethyl sulfoxide (DMSO). The dilution/crystallization kinetic behavior of FOX-7 in DMSO/water system was investigated and the kinetic equation describing the dilution/crystallization process was presented. [Copyright &y& Elsevier]

Molecular dynamics simulation on the reaction of nano-aluminum particle and water were performed by ReaxFF force field. The different reaction rates of aluminum with H 2 O and D 2 O indicate that the effect of kinetic isotope effect (KIE) is obvious. The generation rate of H 2 is 20% higher than that of D 2. The mechanism of formation and consumption of AlH 3 as well as the generation of Al 2 O 3 are elucidated. Specifically, the most frequent reaction pathways throughout the full period are clarified based on the changes of numbers of intermediate and final products. The reactions in the early period are endothermic and release isolated H atoms, which involves Al +3H 2 O → Al(OH) 3 + 3H and 3Al + 2H 2 O → 2AlO + AlH 3 + H. Afterwards, the reactions release a large amount of energy and generate H 2 molecules in the later period, in accordance with the equations of 2AlO + H 2 O → Al 2 O 3 + H 2 , Al(OH) 3 + AlH 3 → Al 2 O 3 + 3H 2 and 2AlH 3 + 3H 2 O → Al 2 O 3 + 6H 2. The initial pathways are in agreement with early DFT investigations. The diffusion coefficients of the different atoms show that the replacement of H 2 O by D 2 O reduces the diffusion rate of all the atoms (5%) in the system. The KIE is confirmed, and the results agree with experiments. In addition, the simulations were performed under different maximum temperatures. Results show that the solid residues become more disperse in space as the temperature increase. Evolution of condensed products and fragments to find new reaction pathways. Image 1 • The generation rate of H 2 is 20% higher than that of D 2. • Isolated H atoms are generated by the reaction of Al and H 2 O. • AlH 3 , Al(OH) 3 and AlO are consumed to generate Al 2 O 3 and release energy. • Solid residues become more disperse in space as the temperature increases. [ABSTRACT FROM AUTHOR]

4-Amino-3-furazanecarboxamidoxime (AAOF) is an important precursor for synthesizing new furazano (furoxano) energetic compounds. Its thermal behaviour was studied under a non-isothermal condition by DSC methods. The results of this study show that there are one melting process and two exothermic decomposition processes. Its kinetic parameters of the intense exothermic decomposition process are obtained from analysis of the DSC curves. The apparent activation energy ( E a ), pre-exponential factor ( A ) and the mechanism function ( f ( α )) were (146 ± 18) kJ · mol −1 , (10 10.9±1.8 ) s −1 and (1 − α ) 2 , respectively. The specific molar heat capacity ( C p ,m ) of AAOF was determined by a continuous C p mode of micro-calorimeter. The self-accelerating decomposition temperature ( T SADT ), thermal ignition temperature ( T TIT ) and critical temperatures of thermal explosion ( T b ) were obtained to evaluate its thermal safety. [ABSTRACT FROM AUTHOR]

Seeded emulsion polymerization of n-butyl acrylate (n-BA) was initiated by a redox initiator system: cumene hydroperoxide/ferrous sulfate hexahydrate/ethylene-diaminetetraacetic acid monosodium salt/sodium formaldehyde sulfoxylate (CHP−Fe2+−EDTA−SFS). Final poly(n-butylacrylate) (PBA) particles with narrow size distribution were obtained. The kinetics and mechanism of seeded emulsion polymerization initiated by the redox initiator system were investigated. Special care was focused on effects of component concentration of the redox initiator system on the seeded emulsion polymerization kinetics. Particle growth and pH variation during the polymerization were also studied. It was found that the polymerization rate and the overall conversion increased with increasing CHP and SFS concentration. Interestingly, the optimal molar ratio of CHP/SFS was 1.10/3.81 rather than being equimolar in our work. In addition, an optimal molar ratio of EDTA to ferrous ions (2.19 × 10−5mol/7.12 × 10−6mol) was found. The polymerization rate increased first and then decreased with increases in ferrous ion concentration. The pH value in the system decreased as the polymerization proceeded. A limiting conversion phenomenon of conversion not being able to exceed 20% was found, and an explanation to the limiting conversion was proposed on the basis of the views of the practical cumulative formation constant log KMYand reaction rate comparison. When another activator solution (EDTA/FES/SFS (mol) 2.19 × 10−5/7.12 × 10−6/1.91 × 10−3) was added, the limiting conversion was removed and the final conversion reached 97%. [ABSTRACT FROM AUTHOR]