Preparation Of Copper Nanoparticles And Copper-Silver Bimetal Nanoparticles

Nano-sized metal may display unique properties due to their small dimension and special surface, and the research of metal nanoparticles has become one of most significant themes in the field of nanotechnology. Peculiarly, copper nanoparticles and copper-silver bimetal nanoparticles have attracted increasing attention recently for their low electrical resistance, catalytic activity and selectivity. These nanoparticles can be wildly used in many fields, such as catalyst and high electrical conductivity material. Therefore, the preparation of copper nanoparticles and copper-silver bimetal nanoparticles is very important from both scientific and practical point of view. In this work, we discussed the preparation and the performance of nano-sized copper dry-powders, nano-copper sol in aqueous media for antistatic coating, as well as the synthesis of copper-silver bimetal nanoparticles. The main results obtained are:(1) The preparation of nano-sized copper dry-particles using chemical reduction method was investigated. The work was mainly focused on the effect of the ratio of reactants, the surfactants and their amount, hydrothermal process, complexing-agent, pH value, the time of chemical aging on the purity, crystallization, aggregation and particle size. The results indicated that the purity and dispersed state of products can be controlled by changing the complexing-agent and the amount of surfactant. The well dispersed spherical copper nanoparticles with the particle size of20nm can be obtained on the condition that ammonia was used as complexing-agent with pH=E3and the amount of surfactant-1was C3. Moreover, the nano-sized copper dry-particles with high purity and crystallization can be obtained after hydrothermal process.(2) Nano-copper sol dispersed in aqueous media was prepared, and the antistatic ability was also tested by added into MF resin. The results revealed that nano-copper sol can be obtained when the mass concentration of copper was less than G6with the protection of surfactant-1. The amount of surfactant-1and the mass concentration of copper were the two important factors that affected the stability of nano-copper sol. The longest suspended time of nano-copper sol can reached35h when the theoretical mass concentration of copper was G1and the amount of surfactant-1was H3. Furthermore, the stability of nano-copper sol can be improved by added into MF resin, and the antistatic ability of MF resin can be promoted with the increase of the amount of nano-copper sol.(3) Copper-silver bimetal nanoparticles with antioxidation were prepared by chemical replacement and co-precipitation method, and we also synthesized copper-silver bimetal nanoparticles by nucleation growth method innovatively. Compared these three methods, it can be concluded that nucleation growth method have great advantages than the others, considering that this method can induce well-proportioned and well-dispersed copper-silver bimetal nanoparticles while other methods tend to produce the mixture of copper and silver nanoparticles.