Research On The Preparation And Dispersion Technology Of Nano-copper Powder

Nano materials with different physical and chemical properties of conventional materials, and is widely used in various fields. At present, there are a variety of methods for preparing nano materials. From the aspects of production process, chemical preparation of nano material has the advantages of high production efficiency, convenient operation, low equipment requirements, etc. but the production process is accompanied by pollution and the preparation technology is instable. From the quality of metal nanoparticle, the physical method has obvious advantages, and the whole preparation process is friendly to the environment.Wire electrical explosion method is a new physical form for preparing nano material, Which has many advantages, such us, simple operation, adjustable process parameters, high energy utilization rate, narrower particle size distribution and high product purity. However, due to the smaller particle size, nanoparticle has a higher surface energy and chemical activity, which lead to agglomeration and oxidation in the process of preparation and storage, making the application of nano materials is limited greatly.The fluid electric explosive device developed by self-regulating is used to prepare nano-copper powder. Which introduces the liquid spraying circulation device on the basis of the traditional electric explosive device, and forming an uniform and complete oil curtain in the electrical explosion process, making the nano-copper powder immersed in the lubricant base oil directly. So it is significant to reduce the surface energy and improve the dispersion properties of nano-copper powder. X-ray diffraction(XRD) and transmission electron microscopy(TEM) are used to characterize the composition and mophology of nano-copper powder. The TEM images of nano-copper powder are spherical or similar to spherical and a handful irregular-shaped. The particle size distributions range from15nm to55nm and with an average particle size of30nm. Compared with the TEM images of different conditions which with oil curtain and without oil curtain, sedimentation experiments and combined with the Ultraviolet-visible spectroscopy(UV-Vis) to illustrate the liquid spraying circulation device can effectively avoid the agglomeration of nano-copper powder, while can reduce the oxidation and improve the purity of nano-copper powder. Subsequently, the dispersing experiments are carried out. Oleic acid as the surfactant, and using its steric-hinerance effect to change the surface character of the nano-copper powder, so as to prevent the particle’s agglomeration. The absorbance values of nano-copper powder are measured at the maximum absorption wavelength by changing the the volume percentage concentration of oleic acid, and drawing the concentration-absorbance curve to obtain the optimal amount of oleic acid.