碳纳米管/高氯酸铵复合粒子的制备及热分解性能

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。     

纳米Fe_3O_4纤维的制备及对高氯酸铵热分解的影响

以五羰基铁为铁源,N,N-二甲基甲酰胺(DMF)为还原剂,采用水热法制备纳米Fe_3O_4纤维。利用X射线衍射(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)和电子能谱(EDS)对产物的晶面结构、表面形貌和元素组成进行表征,并对反应机理进行探讨。结果表明,制备的纳米Fe_3O_4为纤维状,由许多球状颗粒定向连接而成;体系中DMF浓度对产物形貌存在显著的影响。将制备的纳米Fe_3O_4纤维作为高氯酸铵(AP)热分解的催化剂,通过差示扫描量热手段(DSC)研究发现,纳米Fe_3O_4纤维可显著促进AP的热分解。     

高氯酸铵/石墨烯纳米复合材料的制备及热分解行为

通过溶胶-凝胶法制备了高氯酸铵/石墨烯气凝胶(AP/GA)纳米复合材料,用SEM、元素分析和XRD对其结构进行了表征,用TG-DSC-IR联用技术对其热分解行为进行了研究.结果表明,AP/GA纳米复合材料中,AP以纳米尺寸存在于石墨烯气凝胶中,AP质量分数高达94.4％,平均粒径约为69.41 nm.石墨烯对AP的热分解过程具有明显的催化作用,与AP相比,AP/GA纳米复合材料的低温分解峰消失,高温分解峰温降低了83.7℃.总分解热达2110J/g.     

化学镀法制备纳米镍及其对高氯酸铵热分解的催化作用

采用化学镀镍工艺制备纳米镍粉,用TEM和XRD等分析仪器对纳米镍粉的结构和特性进行表征。所得纳米镍粉不含氧化物质,呈球形,为面心立方晶体,平均粒径约60 nm。采用热分析实验（TG-DTA）研究纳米镍对高氯酸铵热分解的催化作用。结果表明,在高氯酸铵中加入质量分数5%的纳米镍粉,高氯酸铵的低温热分解峰和高温热分解峰分别提前了约17 ℃和72 ℃,纳米镍粉对高氯酸铵热分解催化作用明显。     

纳米级金属和金属复合物粉末对高氯酸铵和高氯酸铵/聚合丁二烯复合固体推进剂热分解特性的影响

Effects of metal (Ni, Cu, Al) and composite metal (NiB, NiCu, NiCuB) nanopowders on the thermal decomposition of ammonium perchlorate (AP) and composite solid propellant ammonium perchlorate/hydroxyterminated polybutadiene (AP/HTPB) were studied by thermal analysis (DTA). The results show that metal and composite metal nanopowders all have good catalytic effects on the thermal decomposition of AP and AP/HTPB composite solid propellant. The effects of metal nanopowders on the thermal decomposition of AP are less than those of the composite metal nanopowders. The effects of metal and composite metal nanopowders on the thermal decomposition of AP are different from those on the thermal decomposition of the AP/HTPB composite solid propellant.     

聚合物分散剂对纳米四氧化三钴制备的影响

在均匀沉淀法制备纳米Co3O4的过程中,研究了加入聚乙二醇(PEG-600,PEG-1000)和低相对分子质量的聚丙烯酸钠(PAANa)作为分散剂对前驱体和产物的影响。研究结果表明:加入聚合物分散剂后,能有效地防止纳米粒子的团聚,并能通过聚合物分散剂的相对分子质量来控制产物粒子的形状和大小;当PEG-1000的用量为40mg/mL时,可以获得平均粒径为20nm左右的球形Co3O4;当PAANa用量在15mg/mL左右时,可得到粒径     

钴纳米粒子的制备,特性及应用

纳米粒子(又称团簇、超微粒、超小粒子、量子点等)一般是指尺寸在1～100nm之间的粒子,是处于原子簇和宏观物体交界的过渡区域,从通常的关于微观和宏观的观点看,这样的系统既非典型的微观系统亦非典型的宏观系统,是一种典型的介观系统。纳米材料具有明显的表面效应、体积效应、量子尺寸效应和宏观隧道效应,这些不同于体相材料和单个分子的特性,使其在陶瓷、化工、电子、光学、生物、医药等许多方面有重要的应用价值。自80年代以来,纳米粒子的研究已成为世界性的热点之一。本文对钴及其化合物纳米粒子的制备、特性及应用等方面作一综述。 1 制备 纳米粒子制备方法很多,传统的物理方法     

铁酸铋/石墨烯纳米复合材料的制备及其对高氯酸铵热分解的催化作用

为了提高纳米复合金属氧化物对高氯酸铵(AP)热分解的催化作用,以Bi(NO₃)₃·5H₂O、Fe(NO₃)₃·9H₂O和GO为前驱体,采用水热法制备了铁酸铋/石墨烯(BiFeO₃/rGO)纳米复合材料;利用XRD、FT-IR、XPS、TGA、SEM和TEM等对所制备样品的结构、粒径及形貌进行了表征;采用差热分析研究了不同添加量的BiFeO₃/rGO纳米复合材料对AP热分解过程的影响,分析了BiFeO₃/rGO对AP热分解的催化机理及其对AP热分解动力学的影响。结果表明,rGO的引入有效阻止了纳米BiFeO₃颗粒的团聚,大大增加了比表面积;当BiFeO₃/rGO纳米复合材料的质量分数为4%时,AP的高温分解峰降低最多,达167℃,表观分解热增加了1631J/g,达2518J/g,表观活化能从172.07kJ/mol降低至128.35kJ/mol,表明所制备的BiFeO₃/rGO纳米复合材料能有效催化AP的热分解。     

纳米金属粉及Fe2O3对高氯酸铵热分解的催化性能研究

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.     

气雾化Al-Li合金对高氯酸铵热分解特性的影响

采用紧耦合气雾化法制备了一系列Al-Li合金粉体,利用DSC研究了它们对高氯酸铵(AP)热分解的影响。结果表明Al-Li抑制AP的低温分解,但促进AP的高温分解,使得AP的两个分解峰相互靠近并结合成一个集中的放热峰。当锂含量达10wt%时,合金能够使AP的高温分解峰降低约80℃,表观分解热增加至1046. 2 J/g,并使混合物的高温分解活化能由纯AP的139. 4 kJ/mol降低至76. 5 kJ/mol。此外,对分解产物进行分析,发现Al-10Li合金粉体能够有效减少Cl~-的排放。     

纳米钛酸锌的制备及其对AP热分解性能的影响

以四氯化钛、六水硝酸锌为原料,碳酸铵为沉淀剂,制备了纳米ZnTiO3的粉体,用X射线衍射、红外光谱和透射电镜等对产物进行表征,用差热分析考察了纳米ZnTiO3对高AP热分解的催化作用.结果表明,在550℃可制得结晶良好的立方相纳米ZnTiO3,呈球形或近似球形,粒径约100 nm.在AP中加入质量分数5%的纳米ZnTiO3,AP的低温和高温热分解峰分别提前约18.3℃和25.1℃;提高纳米ZnTiO3的含量可以增强对AP高温热分解反应的催化作用,阻碍AP的低温热分解.     

Preparation of Magnesium‐based Hydrogen Storage Materials and Their Effect on the Thermal Decomposition of Ammonium Perchlorate

Magnesium‐based hydrogen storage materials (MgH₂, Mg₂NiH₄, and Mg₂Cu‐H) were prepared and their structures were determined by XRD and ICP investigations. Mg₂NiH₄ has a monoclinic crystal structure and Mg₂Cu‐H is a mixture of MgCu₂ and MgH₂. The effects of magnesium‐based hydrogen storage materials on the thermal decomposition of ammonium perchlorate (AP) were studied by thermal analysis (DSC). It was found that magnesium‐based hydrogen storage materials show obvious boosting effects on the thermal decomposition of AP. The thermal decomposition peak temperature of AP was decreased, while the heat release of the decomposition of AP was increased. It was revealed that the effects of magnesium‐based hydrogen storage materials on the decomposition of AP become stronger with increasing content. The influence mechanism on the thermal decomposition of AP is suggested as follows: hydrogen released from magnesium‐based hydrogen storage materials and Mg, Ni, or Cu react with the decomposed products of AP.     

CuO/Al复合材料的制备及对高氯酸铵催化作用研究

为了改善固体推进剂中高氯酸铵（AP）热分解性能,本文利用溶胶凝胶法制备了CuO/Al复合催化剂,并利用SEM、XRD等手段对其形貌和结构进行了表征,通过DSC方法考察了催化剂对AP 热分解的催化效果。结果表明：CuO/Al催化剂复合结构完整,其对AP的催化效果明显优于普通混合物CuO/Al的催化效果,并对比了加入1%、3%、5%不同质量分数的CuO/Al复合催化剂的催化效果,发现当加入量为5%时,低温分解峰和高温分解峰分别降低24.2℃和120.2℃,表明所制备的CuO/Al复合催化剂可有效降低AP的热分解温度,改善其热分解性能。     

高氯酸铵复合物研究概况

对近年来高氯酸铵(AP)与推进剂燃烧剂、燃烧催化剂、高导热材料碳纳米管(CNTs)组成的复合物的热分解性能进行了总结,介绍了燃烧剂、催化剂和CNTs在含AP推进剂中的应用效果。结合当前含AP推进剂研究现状,认为AP复合处理是改善推进剂燃烧性能、能量性能和工艺性能的新型方法和有效途径,AP复合物具有良好的工程应用前景。     

纳米MnFe2O4的制备及其对高氯酸铵热分解的催化性能（英文）

Nano-MnFe2O4 particles were synthesized by co-precipitation phase inversion method and low-temperature combustion method respectively, using MnCl2, FeCl3, Mn(NO3)2, Fe(NO3)3, NaOH and C6H8O7. X-ray diffraction (XRD), transmission electron microscope (TEM), Fourier transform infrared spectroscopy (FT-IR), thermogravim-etry-differential thermal analysis (TG-DTA) and differential scanning calorimetry (DSC) were used to characterize the structure, morphology, thermal stability of MnFe2O4 and its catalytic performance to ammonium perchlorate. Results showed that single-phased and uniform spinel MnFe2O4 was obtained. The average particle size was about 30 and 20 nm. The infrared absorption peaks appeared at about 420 and 574 cm-1, and the particles were stable below 524 ℃. Using the two prepared catalysts, the higher thermal decomposition temperature of ammonium perchlorate was decreased by 77.3 and 84.9 ℃ respectively, while the apparent decomposition heat was increased by 482.5 and 574.3 J?g?1. The catalytic mechanism could be explained by the favorable electron transfer space provided by outer d orbit of transition metal ions and the high specific surface absorption effect of MnFe2O4 particles.     

Nano‐Computed Tomographic Measurements of Partially Decomposed Ammonium Perchlorate Particles

High performance solid rocket motors typically contain ammonium perchlorate (AP) particles as the oxidizer. Ammonium perchlorate provides good performance, but thermal decomposition leads to safety concerns for handling and storing solid propellant. Computed tomography is shown to allow for visualization of the AP decomposition process, providing in‐situ, quantitative data. The current work demonstrates the use of nano‐computed tomography (nano‐CT) scanning to elucidate aspects of AP decomposition by studying partially decomposed 400 μm diameter AP particles after isothermal heating at 200 °C. Data provides insight into shape and location of the pores. Analysis shows that the porosity developed within the particle begins approximately 15 μm below the particle surface and moves inward as well as outward towards the surface as the heating time increases. No substantial heating time dependence was observed on the pore size distribution. The size and location distributions of decomposition sites forming below the AP particle surface were quantified for the first time. Comparisons to previous work are discussed.     

高氯酸铵比表面积对推进剂热稳定性的影响

研究了高氯酸铵（ＡＰ）比表面积对推进剂热稳定性的影响。ＡＰ比表面积的增大会导致推进剂初始分解温度、高低温热分解峰温和高低温下分解反应活化能的降低，但分解反应速度常数随ＡＰ比表面积的增大而增大。键合剂可以改善推进剂的热稳定性。     

甲酸铵催化转移氢化法制备龙血素A和龙血素B

利用催化转移氢化将查耳酮还原为二氢查尔酮,在反应中研究了以甲酸铵作为氢给予体,Pd/C为催化剂,不同溶剂,不同温度及催化剂的量对反应的影响,并对反应条件进行优化,产率在60%以上。此法与直接加氢还原法比较具有安全性高、反应温度低、设备要求低和选择性高、后处理简单等优点,该法在二氢查尔酮的制备中得到较好结果,具有较广泛的用途。