Papers by Keyword: Nano Metal

Abstract: Nano Metal/C (Metal=Fe, Co) composite materials, in which nano iron and cobalt particles were uniformly distributed in carbon matrix, was prepared by pyrolysis of M-exchanged cation exchange resin(M-PAA). X-ray diffraction (XRD), Transmission Electron Microscope (TEM) results showed the particle size and morphology of nano iron and cobalt in M/C could be controlled by pyrolytic temperature. The particle size of Co and Fe in M/C obtained at 500 was respectively 15-40 nm and 10-35 nm. DTA was employed to test the thermal decomposition of ammonium perchlorate (AP) in the M/C and AP mixture. Results indicated the decomposition temperature at high-temperature decomposition of AP was lowered with the addition of amount of M/C-500, and the high temperature decomposition peaks of AP respectively lowered as much as 145.2°Cand 68.3°C with adding amount of 5% of Co/C and Fe/C obtained at 500 . The high and low temperature decomposition peaks of AP overlapped with addition of Co/C.

Abstract: In the present work, an extensive research program has been undertaken to characterise a wide spectrum of properties of nano-metals. In particular, the effect of grain refinement on such properties as fatigue, corrosion and wear resistance, conductivity and thermal stability has been studied for various nano-metals (aluminium, copper and iron alloys). The results have revealed that nano-grain refinement also improves physical properties of single phase metals. A disadvantageous effect of large (micron sized) particles, which do not undergo refinement during the processing, has been also recognized.

Abstract: Tungsten oxide nanorods were prepared in a hot filament chemical vapor deposition (HFCVD) reactor. A mixture of gases containing hydrogen, oxygen or hydrogen and methane mixed with water vapor were passed into a quartz glass jar reactor and activated using a heated tungsten filament. The resulting deposits were characterized by transmission electron microscopy (TEM), x-ray diffraction (XRD), and Raman Spectroscopy. The deposit consisted of tungsten oxide nanorods (5 – 10 nm diameter and 50 – 75 nm long) and tungsten nanospheres with diameters of ~50nm. The tungsten oxide is then reduced to metallic tungsten by annealing in a hydrogen environment.