Studies On The Preparation And Properties Of Nanocrystalline Catalysts Used In Explosives And Propellants

The technology of propellants and explosives is one of the key national defence technologies that are largly developed in many countries. The combustion property of propellants and explosives is the most important technology of propellants and explosives. Using less combustion catalyst is the best method that is used to adjust the combustion property of propellants and explosives, especially solid propellants. In this Ph. D. dissertation, a series of nanometer combustion catalysts with different sorts and microstructures were prepared, and the catalysis of these nanometer materials on the energetic material was investigated in order to obtain the preparation technology of nanometer combustion catalysts and the more strongly active catalysts and the influence of the microstructure of such catalysts on their catalytic activity. These results will have important significance on developing new propellants and explosives that have better properties. The dissertation was mainly discussed as follows:1. Firstly, nanocrystalline CuO, PbO, Fe2O3 et al. were prepared, because these mono-metal oxides are usually used in propellants and explosives. The catalysis of these nanoscale materials on the thermal decomposition of energetic material NH4CIO4 (AP) was investigated by thermal analysis. Results indicate that the nanocrystalline CuO powders have more strongly catalytic activities than the others. Nanoscale CuO ( 2 wt %) makes the higher temperature peak of AP thermal decomposition drop down 85.46 癈 and makes the exothermic quantities of AP thermal decomposition rise to 1280 J/g from 590.12 J/g.2. Secondly, the catalysis of nanoscale CuO prepared by different methods on AP thermal decomposition was investigated. Results indicate that the nanoscale CuO prepared by fast precipitation method has more strongly catalytic activities than the others prepared by solid-state methods. The effect of fast precipitation conditions on the microstructure of nanoscale CuO was systemically studied. It is found that the microstructure of nanoscale CuO is influenced by the thermal temperature, precipitant, dispersing media, and additive PEG The different size(e.g. 6-65 nm) and morphology (e.g. ball, ellipsoid, and flower shape with better dispersion) of nanoscale CuO can be obtained by controlling preparation conditions. Some nanoscale CuO samples possess specific surface area of 112.4 m2/g. CuO nanorods with better dispersion were designed andsuccessfully fabricated by additive PEG. Besides, the FT-IR of nanoscale CuO was investigated, and the mechanism of formation of nanocrystalline CuO was discussed.3. The catalysis of the different microstructure of nanocrystalline CuO on AP thermal decomposition was investigated by thermal analysis. Results indicate that the catalytic activities of the nanocrystalline CuO on the thermal decomposition of AP have relations to the microstructure of nanocrystalline CuO. Compared with the average particle sizes of nanocrystalline CuO, the influence of the morphology and surface structure of nanocrystalline CuO samples on its catalytic activity is much greater. The spherical shape nanocrystalline CuO with better dispersion( 2 wt %) can make the higher temperature peak of AP decomposition drop down 99.13 C and the exothermic quantities of AP decomposition rise to 1380 J/g from 590.12 J/g. The nanocrystalline CuO samples prepared by using C2H5OH and DMF (H2O 10 vol %) as dispersing media make the higher temperature peak of AP decomposition drop down 101.33 C and 105.23 C, and the exothermic quantities of AP decomposition rise to 1350 J/g and 1420 J/g, respectivly. Moreover, lots of nanocrystalline CuO samples prepared by fast precipitation method can make the decomposition content of AP at lower temperature rise to 45 ~ 51 % from about 30 %. In addition, the catalytic mechanism of AP thermal decomposition was discussed.4. In order to enhance nanocrystalline Fe2O3 catalytic activity on the thermal decomposition of AP, nanocrystalline Fe2O3 and nanocrystalline Fe2O3 with...