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To explore the new energetic candidate with high energy and low sensitivity, hexagonal boron nitride nanosheets (hBNNS) are first introduced into the field of energetic materials with a bioinspired strategy, and a novel core@dual shell energetic composite is constructed with 1,3,5,7‐tetranitro‐1,3,5,7‐tetrazocane (HMX) as core, adhesive polydopamine (PDA) as inner shell and hBNNS as exterior shell. The composites are analyzed by several methods to in‐depth investigate the core@dual shell structure and its influence on the performance of energetic crystal. These results indicate adhesive PDA is a crucial bridge between HMX and low contents of hBNNS in core@dual shell structure, and the adhesive PDA is a crucial bridge between the HMX and hBNNS. The coating does not affect the chemical structure and polymorph of HMX. The PDA can stabilize the polymorph of HMX, and hBNNS can increase the thermal stability of HMX. The nonisothermal analysis further shows HMX@PDA@hBNNS composites exhibit better thermal stability than that of HMX and HMX@PDA by increasing the apparent activation energy. Furthermore, the coated PDA and hBNNS can reduce the impact and friction sensitivities significantly, precisely because of the buffering effect of "soft" hBNNS and isolation effect of dual shell. [ABSTRACT FROM AUTHOR]

The cocrystal of 2,4,6,8,10,12‐hexanitrohexaazaisowurtzitane (HNIW) with 2,4,6‐trinitrotoluene (TNT) (in a 1 : 1 mole ratio) was prepared by a solvent /non‐solvent (acetonitrile/distilled water) method, and systematically characterized by several methods. The thermal decomposition kinetics of HNIW ⋅ TNT cocrystal were investigated using dynamic Differential Scanning Calorimetry (DSC), and the apparent activation energy (Ea) was calculated by Kissinger‐Akahira‐Sunose (KAS), Flynn‐Wall‐Ozawa (FWO) and Starink methods. The standard molar enthalpy of formation (ΔfHmθ) of HNIW ⋅ TNT cocrystal was acquired by a DC08‐1 Calvet microcalorimeter with the help of a rational thermochemical cycle and was 324.45±0.15 kJ mol−1. A continuous Cp mode of Micro‐DSC III was used to determine the specific heat capacity (Cp,m) of HNIW ⋅ TNT cocrystal from T=(283.15–333.15) K, and the Cp,m was 673.62 J mol−1 K−1 at 298.15 K. [ABSTRACT FROM AUTHOR]

2,4,6,8,10,12-Hexanitro-2,4,6,8,10,12-hexazisowurtzitane (HNIW)·1,3,5,7-tetranitro-1,3,5,7-tetrazocane (HMX) co-crystal in a 2:1 molar ratio was prepared by a solvent/non-solvent method, and the co-crystal has been characterized by several methods. The enthalpies of dissolution of 2HNIW·HMX co-crystal in N,N-dimethylformamide at different temperatures were measured by a DC08-1 Calvet microcalorimeter under standard atmospheric pressure, and it is indicated that the dissolutions are exothermic process. The empirical formulae for the calculation of the molar enthalpy (ΔdissH) of dissolution, relative partial molar enthalpy (ΔdissHpartial), relative apparent molar enthalpy (ΔdissHapparent), and enthalpy of dilution (ΔdilH1,2) at 298.15 K are obtained. The differential enthalpies (ΔdifH) and kinetic equations describing the dissolution process at different temperatures are deduced. Furthermore, the apparent activation energy E = 10.54 ± 0.22 kJ mol-1 and pre-exponential constant A = 0.34 ± 0.03 s−1 of 2HNIW·HMX co-crystal are obtained. The standard molar Gibbs free energy of activation (ΔG≠θ) at different temperatures is 86.44 ± 0.02 kJ mol−1 (298.15 K), 88.02 ± 0.03 kJ mol−1 (303.15 K), 89.61 ± 0.01 kJ mol−1 (308.15 K), 91.18 ± 0.01 kJ mol−1 (313.15 K), and 92.75 ± 0.02 kJ mol−1 (318.15 K), respectively. The standard molar entropy of activation (ΔS≠θ) and standard molar enthalpy of activation (ΔH≠θ) are − 262.55 ± 0.72 J mol−1 K−1 and 7.98 ± 0.22 kJ mol−1, respectively. [ABSTRACT FROM AUTHOR]

[Display omitted] • The pyrolysis mechanism of n -heptane are investigated using ReaxFF simulations and DFT calculations. • The initiation reactions of pyrolysis are detailed analyzed. • The cleavage of C C bonds is the easiest. • The kinetic analysis of n -heptane pyrolysis has been carried out. The pyrolysis of endothermic hydrocarbon fuel with high heat sink can reduce the surface temperature of engines and aircraft fuselage. The pyrolysis mechanism of n -heptane as a model compound for endothermic hydrocarbon fuel was investigated by using ReaxFF reactive molecular dynamic simulations and density functional theory calculations. The results showed that the breakage of C C bonds of n -heptane were easier than that of C H bonds, in which the cleavage of C2 C3 bond is the easiest to generate C 2 H 5 and C 5 H 11 radicals. Temperature has a significant effect on the pyrolysis process of n -heptane, and the increase of temperature will accelerate the pyrolysis of n -heptane and promote the formation of pyrolysis products. The pre-exponential factor and apparent activation energy of the n -heptane pyrolysis were 5.4456 × 1014 s−1 and 231.3 kJ·mol−1, respectively. [ABSTRACT FROM AUTHOR]

• PAN-TeMe and PAN- b -PHEA were synthesized and characterized via TERP. • Polymerization behavior of PAN-TeMe and HEA at different temperatures were investigated by a micro-calorimeter. • Kinetics equations and parameters of polymerization were obtained at different temperatures. • Thermodynamics parameters of polymerization were acquired. The polyacrylonitrile- b -poly(hydroxyethyl acrylate) (PAN- b -PHEA) was synthesized of polyacrylonitrile-TeMe (PAN-TeMe) and 2-Hydroxyethyl acrylate (HEA) via organotellurium-mediated living radical polymerization (TERP), and the PAN-TeMe and PAN- b -PHEA were characterized by several methods. A Calvet micro-calorimeter was used to investigate the polymerization of PAN-TeMe and HEA at different temperatures (358.15 K, 363.15 K, 368.15 K, 373.15 K, 378.15 K and 383.15 K). The kinetic equations of polymerization at different temperatures were obtained, and the apparent activation energy (E) of polymerization is 16.43±0.17 kJ∙mol−1 and the pre-exponential factor (A) is 0.6845±0.0366 s−1. Furthermore, the thermodynamic parameters including the standard molar Gibbs free energy of activation (Δ G ≠ θ), the standard molar enthalpy of activation (Δ H ≠ θ) and the standard molar entropy of activation (Δ S ≠ θ) are acquired. [ABSTRACT FROM AUTHOR]

[Display omitted] • Development of a slab model for alumina-loaded Pt/Ba, considering the effects of both sites simultaneously. • The species exchange process of nitrogen-containing species between proximate Ba and Pt sites is different from the conventional view. • A good linear relationship between NOx adsorption energy and its migration energy barrier. • Detailed electronic structure analysis reveals the reason in essence. Based on density functional theory (DFT) calculations, NO x tends to migrate from Ba to Pt sites within the Lean NO x trap (LNT), rather than reacting at Pt sites before migrating to Ba sites for storage as traditionally believed. Compared with NO and N 2 O, NO 2 has the highest migration energy barrier, and there is a good linear relationship between the adsorption energy of NO x and its migration energy barrier. Furthermore, the essential cause of the above phenomenon is revealed. This study contributes to the exchange of NO x between noble metal catalytic sites and alkaline earth metal storage sites within the LNT. [ABSTRACT FROM AUTHOR]

• OPCH with hydrophilic micropores was synthesized from microalgae to optimize SSG. • OPCH significantly reduced water's evaporation enthalpy from 2216.06 to 1107.88 J g−1. • OPCH achieved an impressive evaporation rate of 2.44 kg m−2 h−1 under one sun. • Two types of bonded water contributing to enthalpy reduction were identified by DDTG. • Hydrophilic micropores decreased both the number and the lifetime of hydrogen bonds. Solar steam generation (SSG) using hydrogels is emerging as a promising technology for clean water production. Herein, a novel oxygen-doped microporous carbon hydrogel (OPCH), rich in hydrophilic groups and micropores, has been synthesized from microalgae to optimize SSG. OPCH outperforms hydrogels with hydrophobic porous carbon or nonporous hydrophilic biochar, significantly reducing water's evaporation enthalpy from 2216.06 to 1107.88 J g−1 and activating 42.3 g of water per 100 g for evaporation, resulting in an impressive evaporation rate of 2.44 kg m−2 h−1 under one sun. A detailed investigation into the synergistic effects of hydrophilic groups and micropores on evaporation via a second derivative thermogravimetry method revealed two types of bonded water contributing to enthalpy reduction. Molecular dynamics simulations provided further insights, revealing that the hydrophilic micropores considerably decrease both the number and the lifetime of hydrogen bonds among water molecules. This dual effect not only reduces the energy barrier for evaporation but also enhances the kinetic energy needed for the phase transition, significantly boosting the water evaporation process. The sustained high evaporation rates of OPCH, observed across multiple cycles and under varying salinity conditions, underscore its potential as a highly efficient and sustainable solution for SSG applications. [Display omitted] [ABSTRACT FROM AUTHOR]