共查询到18条相似文献,搜索用时 296 毫秒
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复合纳米材料的制备研究(Ⅰ) 总被引:29,自引:9,他引:20
亚铬酸铜是促进高氯酸铵分解的一种很好的催化剂,但由于以往制备的亚铬酸铜及高氯酸超细微粒易发生团聚,因而并不能最有效地对高氯酸铵的分解起催化作用。本文采用溶剂-非溶剂法,使溶液变为过饱和而析出晶体,高氯酸铵晶体包覆纳米级亚铬酸铜形成复合粒子,较好地解决了这一问题。在复合粒子中,纳米级的亚铬酸铜微粒均匀分散于高氯酸铵中,由于亚铬酸铜纳米粒子具有很大的比表面积和很高的化学活性,因而大大地提高了对高氯酸铵的催化效果,使高氯酸铵的热分解反应温度区间明显前移,热分解反应的激烈程度大大提高。 相似文献
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用热分析法研究了纳米金属粉(Ni,Cu和Al)以及纳米Fe2O3对高氯酸铵(AP)热分解的催化性能.结果表明,质量分数为5%的纳米镍粉、铜粉和铝粉可以明显降低AP的高温分解温度,显示出对AP高温分解反应很好的催化活性;纳米铜粉对AP的低温分解也有很好的催化作用,而纳米镍粉和铝粉却表现出对AP低温分解反应具有一定的阻碍作用.微米级金属粉对AP高温分解反应的催化作用明显小于纳米金属粉.纳米Fe2O3对高氯酸铵的高温分解具有很好的催化效果,并且其催化效果明显优于微米Fe2O3.纳米Fe2O3与AP进行复合处理,可以提高纳米Fe2O3粒子对AP的催化性能. 相似文献
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NiCu复合金属粉的制备及其催化性能 总被引:1,自引:0,他引:1
采用化学还原法制备得到了纳米级NiCu复合金属粉,对其结构进行了表征. 用热分析法研究了纳米NiCu复合金属粉对高氯酸铵(AP)热分解的催化性能. 结果表明,组成为Ni60Cu40的纳米NiCu复合金属粉可使AP的高温和低温热分解温度分别降低140.4和26.8℃,使总表观分解热增至1.29 kJ/g,表现出对AP的高温和低温热分解的显著催化作用. 纳米NiCu复合金属粉的组成对其催化性能有一定影响,以Ni60Cu40的催化效果最强. 纳米NiCu复合金属粉的含量增加,其催化作用增强. 纳米NiCu复合金属粉催化AP热分解的作用机理为:(1) 氧化物在AP热分解起始阶段电子转移过程中的桥梁催化作用;(2) 纳米NiCu复合金属粉与AP分解产物发生反应;(3) 纳米NiCu复合金属粉的表面效应等. 相似文献
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纳米Ni及碳纳米管对AP热分解的催化性能 总被引:4,自引:0,他引:4
分别用溶液还原法和化学沉淀法制备出了纳米NiNi/CNTs复合催化剂粒子,并用TEM,SEM,XRD,FT—IR对其进行了表征;运用差热分析(DTA)研究了纳米Ni及Ni/CNTs复合催化剂粒子对AP热分解性能的影响。结果表明。纳米Ni使AP热分解的高温分解峰温降低104.47C,纳米Ni/CNTs复合催化剂粒子可使AP热分解的高温分解峰温降低137.05℃,证明碳纳米管在纳米Ni对AP热分解的催化过程中起到了很好的助催化作用。 相似文献
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利用TG-DTA分析研究了表面活性改性剂对纳米NiB/SiO2粒子催化高氯酸铵(AP)热分解反应活性的影响.结果表明,十六烷基三甲基溴化铵(CTAB)对SiO2载体表面改性效果最好,对NiB/SiO2粉体催化AP热分解的活性改善最明显.质量分数5%的纳米NiB/SiO2/CTAB粉体将AP的低温热分解质量损失提高了22... 相似文献
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碳纳米管/高氯酸铵复合粒子的制备及热分解性能 总被引:1,自引:1,他引:1
采用溶剂蒸发法制备了碳纳米管(CNTs)/AP复合粒子,并用TEM,SEM,FT—IR和XRD对其进行表征,用DTA研究了纳米复合粒子中CNTs对AP热分解的催化性能,并与纯AP以及相同含量的CNTs与AP简单混合物进行对比。结果表明,CNTs对AP的热分解有一定的催化作用,且CNTs/AP复合粒子中CNTs对AP的催化性能优于CNTs与AP的简单混合物;与纯AP样品相比,复合粒子中AP的高温分解峰温降低了113.9℃,低温分解峰几乎消失,表观分解热由309.92J/g提高到984.18J/g,而CNTs与AP简单混合样的表观分解热为709.50J/g,表明CNTs与AP的复合处理可改善AP的高温热分解性能。 相似文献
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铜铬类催化剂对HTPE低易损推进剂燃烧性能的影响 总被引:1,自引:0,他引:1
采用差示扫描量热仪(DSC)研究了铜铬类燃速催化剂(亚铬酸铜CC01和铜铬复合氧化物CC02)对端羟基聚醚(HTPE)低易损推进剂中的高氯酸铵(AP)、改性硝酸铵(AN)、HTPE黏合剂体系热分解性能的影响。结果表明,加入少量的CC01和CC02均使AP高温分解峰温明显降低了16和29.7℃,AP高温分解活化能依次降低了16.65和22.59kJ/mol,均可提高AP的高温分解反应速率。CC01和CC02均使AN的热分解峰向低温方向依次前移了52.3和53.6℃,均降低了AN的分解活化能,使AN的热分解反应速率提高了3~4倍。CC01和CC02对HTPE黏合剂体系的热分解影响较小。在AP/AN/Al/HTPE低易损推进剂中,分别添加质量分数0.5%的CC01和CC02可显著提高HTPE低易损推进剂在3~15MPa下的燃速,可使推进剂在7MPa下的燃速分别提高34.1%和43.4%,但CC01和CC02对HTPE低易损推进剂在3~9MPa下的压强指数几乎无影响,而9~15MPa下的压强指数有所降低。 相似文献
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Koji Fujisato Hiroto Habu Atsumi Miyake Keiichi Hori Alexander B. Vorozhtsov 《Propellants, Explosives, Pyrotechnics》2014,39(4):518-525
The thermal decomposition behavior and combustion characteristics of mixtures of ammonium dinitramide (ADN) with additives were studied. Micrometer‐sized particles of Al, Fe2O3, TiO2, NiO, Cu(OH)NO3, copper, CuO, and nanometer‐sized particles of aluminum (Alex) and CuO (nano‐CuO) were employed. The thermal decomposition was measured by TG‐DTA and DSC. The copper compounds and NiO lowered the onset temperature of ADN decomposition. The heat value of ADN with Alex was larger than that of pure ADN in closed conditions. The burning rates and temperature of the pure ADN and ADN/additives mixtures were measured. CuO and NiO enhance the burning rate, particularly at pressures lower than 1 MPa, because of the catalyzed decomposition in the condensed phase; the other additives lower the burning rate. This negative effect on the burning rate is explained based on the surface temperature measurements by a physicochemical mechanism, which involves a chemical reaction, a phase change of the ammonium nitrate, and the blown‐off droplets of the condensed phase. 相似文献
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The effect of micro‐ and nanometer‐sized boron particles on boron‐potassium nitrate (BPN) ignition composition was investigated in this paper. As a starting point, thermochemical calculations were made to determine the most promising ignition compositions. Both stoichiometric and fuel‐rich formulations of BPN were produced to observe the performance variation due to boron content. Particle morphology of boron particles and the surface structure of the ignition compositions were investigated by SEM. The influence of micro‐ and nanometer‐sized boron particles on the calorific value, sensitivity properties, and pressure buildup of compositions were investigated. Sensitivity tests showed that all compositions were safe enough for handling. It was seen that although nanometer‐sized boron particles enhanced calorific value and pressurization rate, they did not have a contribution on the maximum pressure level. The maximum adiabatic flame temperature was attained by the stoichiometric composition, but in practice, the stoichiometric composition resulted in much lower performance than the fuel rich composition. Possible reasons for these behaviors of the compositions were discussed in the paper. 相似文献
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纳米TiO2对双马来酰亚胺固化反应的催化作用 总被引:3,自引:0,他引:3
研究了纳米TiO2对双马来酰亚胺树脂固化反应的影响,结果表明,纳米TiO2对双马来酰亚受树脂的固有具催化作用,它可使树脂固温度降低,固化树脂玻璃化温度提高,而保持热氧分解温度不变,纳米TiO2经溶剂处理或放置一段时间后,基本保持原有活性。 相似文献
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