Enhanced gas and plasticizer barrier HTPB composite liner implanted with parallel orientation Fe3O4/RGO nanosheets by an ultrasound/magnet-coassisted method.

It is of great significance to prepare liners with excellent inhibition of energetic plasticizer migration and gas barrier properties. Here, we have successfully prepared magnetic iron oxide decorated reduced-graphene-oxide nanosheets (MRGO) by using ultrasound-assisted method. The obtained MRGO nanosheet-fillers were filled into hydroxyl-terminated polybutadiene (HTPB) which was exposed to a magnetic field (200 mT) to achieve ordered orientation of MRGO in the HTPB matrix (Ordered MRGO/HTPB). The laser confocal microscopy demonstrates that MRGO exhibit ordered orientation structure in HTPB matrix with good dispersion, which renders the HTPB composite liners exhibiting high gas and plasticizer barrier capability, with a reduction of 18.9 % in water vapor permeability and a decrease of 14.1 % in dibutyl phthalate (DBP) migration equilibrium concentration as compared with those of random MRGO embedded HTPB composite liners (Random MRGO/HTPB). Moreover, a theoretical model accounting for such enhanced gas/plasticizer barrier performance of HTPB due to the implantation of order aligned MRGO was established, which shows that the effective diffusion pathways of plasticizer/gas for liner penetration would be significantly enhanced when the MRGO nanosheets are oriented within the HTPB matrix. This work provides an effective and facile strategy toward the design and development of composite liners with high plasticizer/gas barrier performance for industrial applications.

Correlation of Efficient Dispersion and Catalytic Performance of Nanocombustion Catalysts in Energetic Materials: A Case Study of the Nanocopper Oxide Catalyst with Superfine Ammonium Perchlorate.

Obviously, the dispersion of nanocatalytic materials has significant influence on their catalytic performance. In this study, an evaluation method for the dispersion of nanomaterials was established according to the different solid UV absorptions of different substances by taking the dispersion of nanocopper oxide (nano-CuO) in superfine ammonium perchlorate (AP) as an example. The nano-CuO/superfine AP composites with different nano-CuO dispersions can be obtained by changing the process parameters, such as varying the grinding method, the grinding strength, and the grinding time. Three replicate experiments were carried out for different composites to derive the average values of absorbance at 212 nm, and the dispersion of nano-CuO in superfine AP was calculated using the difference equation, as the solid UV curves at 210-214 nm were almost identical for each sample, especially at 212 nm. The properties of different samples were tested by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (IR), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), differential scanning calorimetry (DSC), and thermogravimetry-mass spectrometry (TG-MS). The results show that the particle size and structure of superfine AP in the composites prepared by different methods were not changed. The XRD and IR techniques in this study were unable to characterize the dispersion of nano-CuO in the composites due to its low content. The dispersion of nano-CuO in the nano-CuO/superfine AP composites was significantly enhanced with the increase of grinding strength and grinding time, and the dispersion of nano-CuO was positively correlated with its catalytic performance, which means that the thermal decomposition performance of different composites improved with the increasing dispersion of nano-CuO. Highly dispersed nano-CuO exhibited a significant catalytic effect on superfine AP in TG-MS. The above conclusions demonstrate the accuracy of the difference equation for evaluating the dispersion of nanomaterials based on solid UV curves, which is expected to be used extensively in evaluating the dispersion of nanocatalytic materials in energetic materials.

Research Progress of Self-Healing Polymer for Ultraviolet-Curing Three-Dimensional Printing.

Ultraviolet (UV)-curing technology as a photopolymerization technology has received widespread attention due to its advantages of high efficiency, wide adaptability, and environmental friendliness. Ultraviolet-based 3D printing technology has been widely used in the printing of thermosetting materials, but the permanent covalent cross-linked networks of thermosetting materials which are used in this method make it hard to recover the damage caused by the printing process through reprocessing, which reduces the service life of the material. Therefore, introducing dynamic bonds into UV-curable polymer materials might be a brilliant choice which can enable the material to conduct self-healing, and thus meet the needs of practical applications. The present review first introduces photosensitive resins utilizing dynamic bonds, followed by a summary of various types of dynamic bonds approaches. We also analyze the advantages/disadvantages of diverse UV-curable self-healing polymers with different polymeric structures, and outline future development trends in this field.

The positive correlation between the dispersion and catalytic performance of Fe2O3 nanoparticles in nano-Fe2O3-ultrafine AP energetic composites supported by solid UV-vis spectroscopy.

Recently, the widespread use of nanocatalytic materials has contributed to an enormous improvement in the performance of energetic materials, especially, highly dispersed nanomaterials. However, the lack of quantitative methods for analyzing the dispersion of nanomaterials limits their further widespread use. Although various techniques such as scanning electron microscopy (SEM), transmission electron microscopy (TEM), etc. are used to analyze the relative dispersion of nanomaterials, it is not possible to quantitatively analyze their dispersion. Therefore, there has been an effort to develop new methods for the quantitative analysis of nanocatalytic materials. Fortunately, we were able to analyze the dispersion of nanocatalytic materials using the difference in their UV absorbance. More importantly, we established the corresponding difference equation to quantify the dispersion of nanocatalytic materials, which is capable of quantifying the dispersion of nano-Fe2O3 in nano-Fe2O3-ultrafine AP composites. The accuracy of the difference equation was verified using a variety of techniques and the desired results were obtained. Based on the above conclusions, the quantitative analysis method for the dispersion of nanomaterials that we established is expected to be widely used and promote the development of energetic materials.

Equal-Material Manufacturing of a Thermoplastic Melt-Cast Explosive Using Thermal-Pressure Coupling Solidification Treatment Technology.

To eliminate internal defects of grains developed during melt-cast charging, the formation mechanism and the trend of crystal morphology of internal defects of 2,4,6-trinitrotoluene and 2,4-dinitroanisole-based melt-cast explosives under different process conditions were simulated. The effects of solidification treatment on melt-cast explosive molding quality were investigated by combining pressurized feeding, head insulation, and water bath cooling. The single pressurized treatment technology results showed that grains were exposed to layer-by-layer solidification from outside to inside, resulting in V-shaped shrink areas of the contract cavity in the core. The defect area was proportional to the treatment temperature. However, the combination of treatment technologies, such as head insulation and water bath cooling, promoted longitudinal gradient solidification of the explosive and controllable migration of its internal defects. Moreover, the combined treatment technologies effectively improved the heat transfer efficiency of the explosive with the help of a water bath to reduce the solidification time, thus achieving highly efficient equal-material manufacturing of microdefect or zero-defect grains.

Enhancing the Anti-Migration Performance and Mechanical Properties of EPDM Insulation through Functionalized GO.

The excessive migration of small molecular plasticizers in solid propellants may lead to debonding and changes in combustion characteristics, affecting the safety of solid rocket motors. Herein, two functionalized graphene oxides (GO) were used to enhance the anti-migration performance of EPDM insulation. GO, 3-Aminopropyltriethoxysilane-modified GO (AGO) and octadecylamine-modified GO (HGO) were filled into EPDM to fabricate EPDM insulation. The anti-migration properties and migration kinetics of EPDM insulations were studied using immersion tests. Moreover, the mechanical properties, including the tensile properties, crosslink density, hardness, and aging resistance of different EPDM insulations, were also explored. Compared with GO, AGO, and HGO obviously enhanced the anti-migration and mechanical properties of the EPDM insulations. This study shows that the anti-migration performance of EPDM insulation can be enhanced by functionalized GO.

Transposable element and host silencing activity in gigantic genomes.

Transposable elements (TEs) and the silencing machinery of their hosts are engaged in a germline arms-race dynamic that shapes TE accumulation and, therefore, genome size. In animal species with extremely large genomes (>10 Gb), TE accumulation has been pushed to the extreme, prompting the question of whether TE silencing also deviates from typical conditions. To address this question, we characterize TE silencing via two pathways-the piRNA pathway and KRAB-ZFP transcriptional repression-in the male and female gonads of Ranodon sibiricus, a salamander species with a ∼21 Gb genome. We quantify 1) genomic TE diversity, 2) TE expression, and 3) small RNA expression and find a significant relationship between the expression of piRNAs and TEs they target for silencing in both ovaries and testes. We also quantified TE silencing pathway gene expression in R. sibiricus and 14 other vertebrates with genome sizes ranging from 1 to 130 Gb and find no association between pathway expression and genome size. Taken together, our results reveal that the gigantic R. sibiricus genome includes at least 19 putatively active TE superfamilies, all of which are targeted by the piRNA pathway in proportion to their expression levels, suggesting comprehensive piRNA-mediated silencing. Testes have higher TE expression than ovaries, suggesting that they may contribute more to the species' high genomic TE load. We posit that apparently conflicting interpretations of TE silencing and genomic gigantism in the literature, as well as the absence of a correlation between TE silencing pathway gene expression and genome size, can be reconciled by considering whether the TE community or the host is currently "on the attack" in the arms race dynamic.

Molecular Engineering of Binder for Improving the Mechanical Properties and Recyclability of Energetic Composites.

Mechanical properties and reprocessing properties are of great significance to the serviceability and recyclability of energetic composites. However, the mechanical robustness of mechanical properties and dynamic adaptability related to reprocessing properties are inherent contradictions, which are difficult to optimize at the same time. This paper proposed a novel molecular strategy. Multiple hydrogen bonds derived from acyl semicarbazides could construct dense hydrogen bonding arrays, strengthening physical cross-linking networks. The zigzag structure was used to break the regular arrangement formed by the tight hydrogen bonding arrays, so as to improve the dynamic adaptability of the polymer networks. The disulfide exchange reaction further excited the polymer chains to form a new "topological entanglement", thus improving the reprocessing performance. The designed binder (D2000-ADH-SS) and nano-Al were prepared as energetic composites. Compared with the commercial binder, D2000-ADH-SS simultaneously optimized the strength and toughness of energetic composites. Due to the excellent dynamic adaptability of the binder, the tensile strength and toughness of the energetic composites still maintained the initial values, 96.69% and 92.89%, respectively, even after three hot-pressing cycles. The proposed design strategy provides ideas for the design and preparation of recyclable composites and is expected to promote the future application in energetic composites.

Effects of Vinyl Functionalized Silica Particles on Thermal and Mechanical Properties of Liquid Silicone Rubber Nanocomposites.

It is very important to develop a new method of preparing high-performance liquid silicone rubber-reinforcing filler. Herein, the hydrophilic surface of silica (SiO2) particles was modified by a vinyl silazane coupling agent to prepare a new type of hydrophobic reinforcing filler. The structures and properties of modified SiO2 particles were confirmed using Fourier-transform infrared spectroscopy (FT-IR), X-ray photoelectron spectrometer (XPS), specific surface area and particle size distribution and thermogravimetric analysis (TGA), the results of which demonstrated that the aggregation of hydrophobic particles is greatly reduced. Additionally, the effects of the vinyl-modified SiO2 particle (f-SiO2) content on the dispersibility, rheology, and thermal and mechanical properties of liquid silicone rubber (SR) composites were studied for application toward high-performance SR matrix. The results showed that the f-SiO2/SR composites possessed low viscosity and higher thermal stability, conductivity, and mechanical strength than of SiO2/SR composites. We believe that this study will provide ideas for the preparation of high-performance liquid silicone rubber with low viscosity.

Plasmonic Photocatalysis for CO2 Reduction: Advances, Understanding and Possibilities.

Plasmonic photocatalysis for CO2 reduction is attracting increasing attention due to appealing properties and great potential for real applications. In this review, the fundamentals of plasmonic photocatalysis and the most recent developments regarding its application in driving CO2 reduction are reported. Firstly, we present the review on the mechanism of plasmonic photocatalytic CO2 reduction, the energy transfer of plasmon, and the CO2 reduction process on the catalyst surface. Then, the modulation on the plasmonic nanostructures and also the semiconductor counterpart to regulate CO2 photoreduction is discussed. Next, the influence of the core-shell structure and the interface between the plasmonic metal and semiconductor on the CO2 photoreduction performance is also outlined. In addition, the latest progress on the emerging direction regarding the plasmonic photocatalysis for methane dry reforming with CO2 is especially emphasized. Finally, a summary on the challenges and prospects of this promising field are provided.

Current Self-Healing Binders for Energetic Composite Material Applications.

Energetic composite materials (ECMs) are the basic materials of polymer binder explosives and composite solid propellants, which are mainly composed of explosive crystals and binders. During the manufacturing, storage and use of ECMs, the bonding surface is prone to micro/fine cracks or defects caused by external stimuli such as temperature, humidity and impact, affecting the safety and service of ECMs. Therefore, substantial efforts have been devoted to designing suitable self-healing binders aimed at repairing cracks/defects. This review describes the research progress on self-healing binders for ECMs. The structural designs of these strategies to manipulate macro-molecular and/or supramolecular polymers are discussed in detail, and then the implementation of these strategies on ECMs is discussed. However, the reasonable configuration of robust microstructures and effective dynamic exchange are still challenges. Therefore, the prospects for the development of self-healing binders for ECMs are proposed. These critical insights are emphasized to guide the research on developing novel self-healing binders for ECMs in the future.

Modulating crystal and electronic structure of NiFe-MOFs by inorganic acid for highly efficient electrochemical water oxidation.

Seeking new methods to modulate the structure of metal-organic frameworks (MOFs) for diverse applications, particularly for water splitting, is intensively urgent but challenging. Herein, a simple hydrothermal method employing HCl as the modulator is developed to synthesize a series of NiFe-MOF-n/NF. The amount of HCl modulator not only changes the elemental composition and crystal structure but also modulates the electronic structure of NiFe-MOF-n/NF, thus improving intrinsic activity. Owing to the synergetic interactions between Ni and Fe atoms, free-standing feature, the optimized NiFe-MOF-2/NF yields excellent OER activity with overpotentials of 209 and 260 mV at 10 and 100 mA cm-2, respectively, a small Tafel slope of 36.4 mV dec-1 and excellent OER stability for 24 h at 100 mA cm-2 in 1 M KOH. This demonstrates that NiFe-MOF-2/NF are in situ converted into metal oxide/oxyhydroxide after OER, thereby serving as the real active sites. This study offers a feasible way to fabricate low-cost, efficient MOF-based electrocatalysts.

Dense, Three-Dimensional, Highly Absorbent, Graphene Oxide Aerogel Coating on ZnCo2O4/ZnO Particles Exerts a Synergistic Catalytic Effect for Ammonium Perchlorate Thermal Decomposition.

As a new type of carbon material, graphene oxide aerogel (GA) is widely used in catalysis due to its porous structure, high-efficiency adsorption, and superb conductivity. In this study, GA was prepared into a dense coating layer surrounding ZnCo2O4/ZnO particles to form a composite GA-ZnCo2O4/ZnO by means of a hydrothermal, blast drying, and vacuum-freeze-drying approach applied to catalyze the thermal decomposition of ammonium perchlorate (AP). The physicochemical properties of the obtained GA-ZnCo2O4/ZnO were characterized by different analytical methods. Scanning electron microscopy (SEM) analysis exhibited that GA is coated on the surface of ZnCo2O4/ZnO, forming a dense layer. Brunner Emmet Teller (BET) measurement results show that GA-ZnCo2O4/ZnO has a smooth macropore distribution curve and a larger specific surface area. Moreover, The catalytic effect investigation on AP with GA-ZnCo2O4/ZnO: the high temperature decomposition (HTD) peak temperature of AP in the presence of 5 wt % GA-ZnCo2O4/ZnO was reduced from 441 to 294 °C, and the exotherm of AP was expanded from 205 to 1275 J/g at a heating rate of 15 °C/min. Through the calculation, GA-ZnCo2O4/ZnO makes the activation energy and Gibbs free energy of the AP pyrolysis lower so that the reaction is easier to occur. Thermogravimetric-mass (TG-MS) spectrometry revealed that during thermal decomposition of AP, GA-ZnCo2O4/ZnO leveraged the synergistic catalysis of ZnCo2O4/ZnO and GA that boosted the flow of electrons from ClO4- to O2 and increased the absorption of the gas product to accelerate the AP pyrolysis. These results provided a facile strategy to prepare GA-based composite catalysts with extraordinary application prospects in the domain of solid propellants.

Theoretical simulation study on crystal property and hygroscopicity of ADN doping with nitramine explosives (RDX, HMX, and CL-20).

To effectively modify the strong hygroscopicity of ammonium dinitramide (ADN) crystal, the modification of ADN crystal in the 298 K under vacuum environment was studied through theoretical calculation. Three kinds of energetic nitramine molecules (X = RDX, HMX, and CL-20) were inserted into ADN crystal in different proportions (the molecular ratios of ADN to X are 6/1, 12/1, 18/1, and 24/1), to form a total of 12 kinds of designed ADN crystals. The results show that with the modification of ADN crystal with RDX, HMX, and CL-20, the crystal space group, cell parameters, crystal density, and growth morphology will be changed under vacuum conditions. According to the analyses of adsorption heat data, four proportional modification systems all reduced the hygroscopicity of ADN crystal to varying degrees. It is worth noting that the hygroscopicity of modified ADN crystal tends to decrease with the increase of the proportion of doping molecules, but the stability gradually deteriorates, especially 18ADN/1CL-20 and 24ADN/1CL-20. Although they have an excellent anti-moisture effect, from the perspective of crystal energy stability, the actual syntheses of these two kinds of crystal cells are the most difficult. Combined with the energy stability and hygroscopicity analysis, 1HMX/24ADN crystal is a more suitable anti-hygroscopicity modification scheme among the doped ADN crystals. In this case, the isothermal adsorption heat of ADN crystal decreases from 0.692 kcal/mol to 0.573 kcal/mol. The theoretical simulation study of ADN doping modification in a vacuum will provide significant references for ADN modification in the actual situation.

Evaluation of Blend Uniformity and Terminal Point during Continuous Mixing in Water for Modified Double-Base Propellant Components Using a Near-Infrared Method.

A near-infrared (NIR) spectrometer was used to test the double-base absorbent powder sample and to quantitatively analyze the contents of each component as well as their dispersion uniformity to establish a rapid quantitative test method for blending uniformity of modified double-base (MDB) propellant components. First, the quantitative calibration models of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) were constructed based on sample testing, and the RDX model's correlation coefficient was 0.9929. Then, during the blending process, NIR spectra were continually collected. For the original spectra of samples, the blend uniformity was assessed using the coefficient of moving block standard deviation (MBSD). After 160 min, the sample's MBSD value had reached a steady state of less than 0.003, indicating that the sample's components were distributed uniformly. The findings reveal that NIR spectroscopy can be used to verify the blending uniformity of MDB propellant components.

Covariance matrix reconstruction method based on amplitude and phase constraints with application to extend array aperture.

The angular resolution has always been a concern in the underwater direction of arrival (DOA) estimation. The resolution of the uniform linear array will worsen if the array aperture decreases. When the element spacing is determined, increasing the number of array elements (NAE) can improve the resolution. However, the NAE cannot be greatly increased in practical applications. To address this problem, we propose an array aperture extension method. For this method, we design an optimization algorithm to reconstruct the covariance matrix of the extended array by using that of the original array. Moreover, to make the extended array resemble the actual array, the reconstructed covariance matrix is constrained with a pure signal covariance matrix. The solution method of the optimization algorithm is described in detail. The function of this method is to improve the array aperture by increasing the virtual array elements without changing the element spacing. Therefore, when the array elements are insufficient, this method helps to improve the DOA estimation performance, such as the estimation precision and resolution probability of dual targets. Experiments including simulations and real lake experiments are implemented to validate the effectiveness of the proposed method.

Complete mitochondrial genome of the spectacled parrotbill Sinosuthora conspicillata David, 1871 (Aves: Passeriformes: Sylviidae).

The mitochondrial genome of the spectacled parrotbill Sinosuthora conspicillata is sequenced by the Sanger method. The genome is 16,982 bp in length, comprising of 13 protein-coding genes (PCGs), 2 rRNA genes, 22 tRNA genes, 1 control region (D-loop), and 1 pseudo-control region. The PCGs of COX1 and ND3 use GTG and ATA as their starting codon, respectively, while all other PCGs start with ATG codons. Four PCGs (COX3, ND4, ND5, and ND6) are terminated with CCT, TAT, AGA, and TAG, respectively, and all other PCGs end with TAA. The 22 tRNAs range from 66 bp (tRNA-Ser) to 75 bp (tRNA-Leu) in length. The two rRNAs are 984 bp (12S) and 1600 bp (16S) in length. Phylogenetic analysis indicated that S. conspicillata is closely related to the congeneric vinous-throated parrotbill S. webbiana. This mitochondrial genome sequence offers a valuable resource for future conservation genetic and phylogenetic studies of birds in the family Sylviidae (Passeriformes).

Amido-Functionalized Magnetic Metal-Organic Frameworks Adsorbent for the Removal of Bisphenol A and Tetracycline.

In this paper, amido-functionalized MOFs with core/shell magnetic particles (Fe3O4@MIL-53(Al)-NH2) was prepared by the solvothermal method and characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), Fourier transform infrared (FT-IR), Vibrating Sample Magnetometer (VSM) and UV/VIS spectrophotometer. The influence of different factors on the adsorption effect of the pollutant, including adsorbent amounts, adsorption time, ionic strength and pH, were explored. It was found that the amine-decorated Fe3O4@MIL-53(Al)-NH2 were efficient for removal of contaminant, with the adsorption capacity for bisphenol A (234.1 mg/g) and tetracycline (84.8 mg/g) under the optimized conditions. The adsorption kinetics and the equilibrium adsorption data indicated that the adsorption process of BPA and TC was more compatible with the pseudo-second-order kinetic model and the Langmuir model, respectively. The thermodynamic values show the adsorption of the mentioned contaminant was spontaneous and endothermic. Moreover, the Fe3O4@MIL-53(Al)-NH2 adsorbent had good regeneration and reusability capacity after five cyclic utilization. All these results show Fe3O4@MIL-53(Al)-NH2 adsorbent could be a potential candidate for future water purification.

Effective Magnetic MOFs Adsorbent for the Removal of Bisphenol A, Tetracycline, Congo Red and Methylene Blue Pollutions.

A magnetic metal-organic frameworks adsorbent (Fe3O4@MIL-53(Al)) was prepared by a typical solvothermal method for the removal of bisphenol A (BPA), tetracycline (TC), congo red (CR), and methylene blue (MB). The prepared Fe3O4@MIL-53(Al) composite adsorbent was well characterized by scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray diffraction (XRD), and fourier transform infrared spectrometer (FTIR). The influence of adsorbent quantity, adsorption time, pH and ionic strength on the adsorption of the mentioned pollutants were also studied by a UV/Vis spectrophotometer. The adsorption capacities were found to be 160.9 mg/g for BPA, 47.8 mg/g for TC, 234.4 mg/g for CR, 70.8 mg/g for MB, respectively, which is superior to the other reported adsorbents. The adsorption of BPA, TC, and CR were well-fitted by the Langmuir adsorption isotherm model, while MB followed the Freundlich model, while the adsorption kinetics data of all pollutants followed the pseudo-second-order kinetic models. The thermodynamic values, including the enthalpy change (ΔH°), the Gibbs free energy change (ΔG°), and entropy change (ΔS°), showed that the adsorption processes were spontaneous and exothermic entropy-reduction process for BPA, but spontaneous and endothermic entropy-increasing processes for the others. The Fe3O4@MIL-53(Al) was also found to be easily separated after external magnetic field, can be a potential candidate for future water treatment.

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.