Study On Preparation And Performance Of Copper Nanomaterials And Porous Copper Materials

Copper nanomaterials have been widely used in many fields, such as electronic packaging materials, porous material for cooling, lubricating oil, catalyst, etc. And nanoporous copper(NPC) is of potential use in numerous applications such as catalysts,sensors,actuators, CPU heat dissipation and so on.Copper nanopowders were synthesized by an ionothermal method using Cu(NO3)2 as the copper source, hydrazine hydrate as reducing agent, and different kinds of ionic liquids as reaction medium, under the different reaction temperature.The influence of the type of the reaction medium and the pH value of the solution on the morphology of copper nanoparticles was studied. The prepared samples were characterized by XRD, SEM, XPS and ultraviolet-visible(UV-vis) spectrum,respectively. At the same time, Porous copper heat dissipation materials were prepared by microwave sintering method using copper nanomaterials as raw materials, g-C3N4 as pore forming materials. And the influence factors on the performance of porous copper heat dissipation materials were studied. The main conclusions are as follows:1. When the reaction temperature was between 120℃ and 160℃, the prepared sample was only copper phase, and the sample prepared by the reaction temperature reached 180℃, and the Cu2 O was formed.2. When the reaction medium is tetraethyl ammonium bromide/butanedioic acid ionic liquid system, the prepared copper nanocrystals are triangular, and the copper nanocrystals prepared in the urea/choline chloride reaction medium is not regular sphere.3. In the wavelength range of 300-900 nm, the triangle-like copper nanocrystals exhibited two absorption peaks centered at 525 nm and 605 nm, respectively.4. Through the study of porosity of the porous copper, we can discover when the porosity of porous copper heat dissipation material with the change of coppervolume fraction, the porosity of porous copper gradually reduce; When the temperature rises from 750 ℃ to 800 ℃, the change of porosity is unobvious, and when the temperature exceeds800 ℃ or 825 ℃; However As holding time increased from 10 min to 40 min, the porosity change is very small.5. The investigation on the mechanical properties of porous copper showed that:As the porosity increased, the anti-elastic deformability and the deformation range of the elastic space of the porous copper deceased dramatically. When the quantity of the copper kept as 30%, the mechanical properties of porous copper improved as the sintering temperature increased.6. The investigation on the thermal conductivity of the porous copper showed that: The coefficient of thermal conductivity of porous copper are reduced with the increase of porosity in the porous copper.when Copper sintering temperature less than 775 ℃, thermal conductivity is low, but when sintering temperature at 800 ℃and 825 ℃, the coefficient of thermal conductivity increased significantly.7. From the study results of nanoporous copper dilatation coefficient,we can find that the nanoporous copper dilatation coefficient changed little with the change of copper volume fraction at the same temperature in the temperature range of30℃~150℃, after temperature above 80℃, the nanoporous copper dilatation coefficient was almost the same with the change of copper volume fraction, which fixed at a vaule.