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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]

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]

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 enthalpy of dissolution of FOX-12 in dimethyl sulfoxide (DMSO) was measured by means of a RD496-III Calvet microcalorimeter at 298.15 K. Empirical formulae for the calculation of the enthalpy of dissolution ( $$ \Updelta_{\text{diss}} H $$ ), relative partial molar enthalpy ( $$ \Updelta_{\text{diss}} H_{\text{partial}} $$ ), and relative apparent molar enthalpy ( $$ \Updelta_{\text{diss}} H_{\text{apparent}} $$ ) were obtained from the experimental data of the enthalpies of dissolution of FOX-12 in DMSO. The kinetic equation that describes the dissolution process of FOX-12 in DMSO at 298.15 K is determined as $$ \frac{{{\text{d}}\alpha }}{{{\text{d}}t}} = 8.5 \times 10^{ - 3} (1 - \alpha )^{0.59} $$ . [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 specific heat capacity (C p) of 37.2/44/16/2.2/0.2/0.4-GAP/CL-20/Al/N-100/PCA/auxiliaries mixture was determined with the continuous C p mode of microcalorimeter. The equation of C p with temperature was obtained. The standard molar heat capacity of GAP/CL-20/Al/N-100/PCA/auxiliaries mixture was 1.225Jmol−1 K−1 at 298.15K. With the help of the peak temperature (T p) from the non-isothermal DTG curves of the mixture at different heating rates (β), the apparent activation energy (Ek and Eo) and pre-exponential constant (A K) of thermal decomposition reaction obtained by Kissinger''s method and Ozawa''s method. Using density (ρ) and thermal conductivity (λ), the decomposition heat (Q d, taking half-explosion heat), Zhang-Hu-Xie-Li''s formula, the values (T e0 and T p0) of T e and T p corresponding to β →0, thermal explosion temperature (T be and T bp), adiabatic time-to-explosion (t TIad), 50% drop height (H 50) of impact sensitivity, and critical temperature of hot-spot initiation (T cr,hot spot) of thermal explosion of the mixture were calculated. The following results of evaluating the thermal safety of the mixture were obtained: T be =441.64K, T bp =461.66K, t Tlad =78.0s (n =2), t Tlad =74.87s (n =1), t Tlad =71.85s (n =0), H 50 =21.33cm. [Copyright &y& Elsevier]

The purpose of this study was to characterise the Maillard reaction in a pressurised liquid system containing β-conglycinin and dextran. The rate of browning and the free amino content in this liquid system, with an initial pH of 7.2, were measured after reaction under atmospheric pressure and at 10 MPa. The secondary and tertiary structures of the conjugates were analysed by circular dichroism, showing that the increased pressure accelerated the reaction rate of the free amino groups and reduced the rate of browning. Significant structural changes occurred in the tertiary structure of the conjugates. Additionally, the emulsifying properties of the β-conglycinin–dextran conjugates produced were studied. The emulsifying properties of the conjugates produced at 10 MPa were higher than those made at atmospheric pressure. [ABSTRACT FROM AUTHOR]

Compared to the monometal carbide Ni 3 C, the bimetal carbide Ni 3 ZnC 0.7 possesses the advantageous properties of both sulfophilic sites of Ni and lithophilic sites of Zn, which demonstrates efficient adsorption and catalytic effect towards LiPSs. Therefore, the Li-S battery with the Ni 3 ZnC 0.7 /Ni/NCNTs-based coating separator shows excellent performance even at the high rate of 7C. • The Ni 3 ZnC 0.7 demonstrated efficient adsorption and catalytic effect towards LiPSs. • The Ni 3 ZnC 0.7 possesses both sulfophilic sites of Ni and lithophilic sites of Zn. • The sulfophilic and lithophilic sites can enhance the catalysis of LPSs. • The Li-S battery with bimetal carbide coating shows excellent performance at 7C. The notorious shuttle effect and slow reaction kinetics of lithium polysulfides (LiPSs) severely limit the cycle stability and rate performance of lithium sulfur (Li-S) batteries. Herein, we demonstrated that the issue of shuttling effect of LiPSs could be effectively addressed by using a separator coating based on Ni 3 ZnC 0.7 bimetal carbide nanoparticles dispersed in nitrogen-doped porous carbon material matrix containing small amount of Ni metal particles, namely Ni 3 ZnC 0.7 /Ni/NCNTs. When used as a separator coating of Li-S cells, the Ni 3 ZnC 0.7 bimetal carbides demonstrated efficient adsorption and catalytic effect towards LiPSs, inhibiting the shuttle effect and enhancing the electrochemical performance of device. The Li-S cell still maintained excellent charging and discharging platform even at a high rate of 7C. Theoretical calculation shows that, compared to the monometal carbide Ni 3 C, the bimetal carbide Ni 3 ZnC 0.7 possesses the advantageous properties of both sulfophilic sites of Ni and lithophilic sites of Zn, resulting in reduced energy barriers for lithium ion diffusion and improved catalytic capability, thus enhancing reaction kinetics of LiPSs. This work paves a new way to resolving the critical issues of shuttle effect, cycle stability and rate capability of Li-S batteries by taking advantage of synergistic effect of Ni and Zn in the bimetal carbide. [ABSTRACT FROM AUTHOR]

The lithium–sulfur battery is considered as one of the most promising next-generation energy storage systems owing to its high theoretical capacity and energy density. However, the shuttle effect in lithium–sulfur battery leads to the problems of low sulfur utilization, poor cyclability, and rate capability, which has attracted the attention of a large number of researchers in the recent years. Among them, the catalysts with efficient catalytic function for lithium polysulfides (LPSs) can effectively inhibit the shuttle effect. This review outlines the progress of catalyst materials for lithium–sulfur battery in recent years. Based on the structure and properties of the reported catalysts, the development of the reported catalyst materials for LPSs was divided into three generations. We can find that the design of highly efficient catalytic materials needs to consider not only strong chemical adsorption on polysulfides, but also good conductivity, catalysis, and mass transfer. Finally, the perspectives and outlook of reasonable design of catalyst materials for high performance lithium–sulfur battery are put forward. Catalytic materials with high conductivity and both lipophilic and thiophile sites will become the next-generation catalytic materials, such as heterosingle atom catalysis and heterometal carbide. The development of these catalytic materials will help catalyze LPSs more efficiently and improve the reaction kinetics, thus providing guarantee for lithium sulfur batteries with high load or rapid charge and discharge, which will promote the practical application of lithium–sulfur battery. [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]

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]