The Synthesis And Properties Of Nanomatel Crystals

The nonmaterials have the unique physical, chemical and mechanical properties that are neither those of bulk materials nor those of molecular compounds. They have been exploited for the extensive potential applications in optics, electronics, magnetic, catalyst, sensing, biomedicine, etc. Nowadays a great variety of effective chemical methods have been demonstrated to be able to prepare silver nanostructures. Though on simple method has yet been found to fabricate nonmaterial with arbitrary shapes, polyol process supplies the good way. Reasons for the popularity and versatility of this synthesis included the ability for polyols to dissolve many precursor salts (and ions), their highly temperature-dependent reducing powder, and their relatively high boiling points. In particular, the temperature-dependent reducing power of polyols makes them ideal for the synthesis of colloidal particles over a broad range, as it gives one the ability to control the nucleation and growth processes through careful regulation of reaction temperature. Based on the newest international achievements, synthesis of two kinds of nano metals, silver and bismuth crystals by polyol process, were studied. During synthesis of bismuth nano powders, used solvothermal method as the compared experiment.Well-dispersed silver Nan particles of various morphologies were synthesized in large quantities by reducing silver nitrate with ethylene glycol in the presence of poly(vinylpyrrolidone) (PVP). The effects of the concentration of AgNO₃, reaction temperature, the adding rate of the PVP and AgNO₃ injected into ethylene glycol and the molar ratio between the repeating unit of PVP and AgNO₃ were discussed. By varying reaction conditions, silver nanocubes, nonoprisms and nanospheres could be obtained. Based on the previous studies about the formation mechanism of nano silver crystals, discussed the formation mechanism of nano silver from two stages: nucleation and crystal growth, crystallinity of a seed and the extent of the PVP...