Preparation And Characterization Of Nano-materials By Mechanochemical Method

Material science and technology and their applications are wide used. They are very important support of the national economic, aerospace, aviation, information, defense and other high-tech fields. With the development of science and technology, the composition of the materials were changed from simple to complex, particle size was changed from micron meter to nanometer. In recent years, people have found that nanomaterials have unique physical and chemical properties. Now it is a good opportunity to the research of physics, chemistry, materials, biology, medicine and other disciplines. Therefore, it would be a touch research target to prepare nanomaterials simply and effectively.In this paper, we described the different types of nanomaterials, as well as the main properties and applications, and then enumerated a variety of methods to prepare nanomaterials. We spent a more detailed investigation on the mechano-chemical method to prepare nanomaterials, and introduced a new mechano-chemical method, the screw grinding method.First, traditional mechano-chemical methods, the planetary milling and the sand milling, were employed to synthesis Y stabilized zirconia. Furthermore the screw grinding method was used to synthesis the same powder. After finishing the milling, XRD, SEM and other methods were conducted to characterize these two different kinds of synthesized powders, and compared their advantages and disadvantages. The particle size analysis showed that the planetary ball milling could be used to break large particles of raw materials, mean while, sand milling could be used to crush raw materials to about1μm in size. But according to the phase analysis, the traditional mechano-chemical method had only played a crushing effect, did not synthesize any new phase. The new mechano-chemical method, screw grinding method, could be used to crush raw materials to5μm in size, mean while, to synthesize a new phase. This was because the screw grinding method uses unique shearing force and pressure force to promote the solid state reaction of the row material powder. Aging and wet corrosion resistance were used to characterize the sintered zirconia ceramic, the aging test result showed that the higher Y content could reduce the aging phenomenon effectively.Second, wet chemical methods as the reference methods, the co-precipitation method and the hydrothermal method, were employed to synthesize Mg stabilized zirconia, comparing with the result of Mg stabilized zirconia synthesized by screw grinding method. XRD, SEM and other methods were proceeded to characterize the synthesized powders, and then mechanical performance of sintered ceramics was characterized. Studies had shown that all three synthetic methods could synthesize the required phase effectively. Screw grinding method prepared Mg stabilized zirconia could get the best mechanical performance when sintered at1500℃. The mechanical performance of ceramics prepared by screw grinding method was better than that of co-precipitation method, closing to samples of hydrothermal method.Third, functional materials of PMN and PZT were synthesized by the new mechano-chemical method, the screw grinding method. Through cross-reaction experiments, it was found that the mechanism of mechano-chemical method and solid phase diffusion method were completely different, thus the pyrochlore phase was avoided, and the phase purity of powders was developed. And a higher power could greatly short the time of the mechano-chemical reaction time, improving the phase purity and the dispersion of the powder.Finally, mechano-chemical method was used to prepare MMT nanosheets by controlling the pH value. Aluminosilicate acid nanosheets were obtained by milling method, and the impact of pH value on the nanosheets preparing was studied. Rare earth ion as a fluorescence center assembled on nanosheets was obtained. The luminescent property of nanosheets was studied.