| The nanometer/micrometer composite technology, by which nanometer composite materials with low aggregation of nanometer particles can be prepared, is a new kind of technology in nanometer material field. With the technology, the functional characteristics of nanometer particles can be brought into play adequately. Several kinds of typical materials in nanometer field are chosen to prepare functional nanometer materials in this dissertation. Based on the study of grain composite particles and membrane composite particles, a new kind of functional nanometer composite particle is prepared in the form of nanometer grain/nanometer membrane/micrometer core particle. Through the study of nanometer grain and membrane composite technology separately, as well as the organically combination of grain and membrane composite technology, the theoretical basis and experimental foundation are presented for particles compounding.First, the grain composite technology was studied with the materials of RDX and Al powder. The RDX/Al superfine composite powder was prepared with an YLG model stirring grinding machine. The grinding media (water and alcohol) were compared and studied during the grinding process. The particle composition and their diameters, appearances of the composite particles and their properties of thermodynamics and explosive heat were studied by using the particle diameter sizer, SEM, DSC, XRD and explosive heat testing machine respectively. The study results indicated that the water grinding media may benefit the compounding of particles, while the alcohol grinding media may benefit the superfining and dispersing of particles for the energetic(C2H5O)3Al sample, which was gained in alcohol media. Accordingly the explosive heat was improved of sample ground in alcohol. In order to explain this phenomena, models on the superfining and compounding of particles and the thermolysis of superfine RDX/Al composite explosive were proposed and the models are well in accord with the experiment results.Second, the membrane and grain composite technologies were studied for compounding materials of TiO2 and SiO2. The nanometer composite particles of nanometer TiO2 covered by nanometer SiO2 membrane as well as nanometer TiO2 particles precipitated on auniform dispersed micrometer SiO2 sphere particle were prepared respectively. The sterilization experiments on several health care foods indicated that the two kinds of nanometer composite particles showed much better sterilization effect than the pure nanometer TiO2. While the samples added with nanometer TiO2/SiO2 membrane composite particles resulted in the lowest bacteria number. After 60 days, the total bacteria numbers of the samples containing membrane composite powder were only 50 to 120 units per gram, only 0.25%~0.7% of the enterprise standards of corresponding health care food, 0.52%~0.97% of the bacteria numbers of blank samples and 33.3%~83.3% of those of samples containing pure nanometer TiO2 powder.Based on the theoretical analysis and the experimental results of the two above-mentioned study, a new kind of composite particles in the form of nanometer grain/membrane/micrometer core particle was prepared by combined the grain and membrane composite technology organically. Nanometer Fe2O3 and micrometer Al were experimented to prepare the grain/membrane/core composite particles. The membrane, which was proved can protect the metal core particles from oxidation, was formed in the preparing process of composite particles. After the composite particle of inorganic membrane covering Al powder is formed, nanometer Fe2O3 is deposited on the surface of membrane. Accordingly the nanometer grain/nanometer membrane/micrometer core particle with catalytic and energetic function is achieved. The application experiments on solid propellant indicated that the decomposition of propellant is accelerated, and that the combustion heat is increased distinctively. A patent has been applied to protect the novel technology, and the patent authorization number is 03105599.0.
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