Research On Preparing Of Copper Nano-particle By Electrochemical Method

This thesis carries on the study of preparing of Copper Nano-particle by electrochemical Method.At the same time,after doing a lot the preparation methods of electrochemical,the preparation method of electrochemical have many excellent characteristics such as the better dispersancy,the better antioxidation,the simple equipments,the cheap cost of production,pollution free,etc.Surface dispersants and modification agent is a key factor to electrodeposit in my thesis.The particle surface will be wrapped by surface dispersants and modification agent before the growing up of the particle.The emulsification makes the powder anti-oxide in atmosphere.At the same time,the preparation of emulsified liquid and the choice principle of surface dispersants and modification agent were analyzed deeply.According to the experimental result,copper nanoparticle can synthesis preparted by no matter single surface dispersants or their composites.Single surface dispersants affect on morphology and particle size distribution of copper nanoparticle greatly,and the preparation of the nanoparticles are easy oxidized.Smaller size,better dispersibility,narrow distribution and better antioxidation of copper nanoparticles can be obtained by use of composites surface dispersants.At last the sodium dodecyl sulfate and tween-80 were selected as surface dispersants,the dodecyl mercaptan was selected as modification agent.The technique process of the nano-particle which uses electrodeposit method and the preparing equipment were explained detaily in this thesis.It is showed that the metallography of particle is like the anode material by XRD testing.It was only changed smaller in size.It was also showed that the surface of powder was wrapped by modification agent,which was measured by infrared equipment testing.The diameter of particle changed with current density,consistence and pH by TEM testing.Base on the single-factor experiments,the Curent density,pH and the consistence of CuSO₄ affect the diameter of particle were investigated.The results are as follows: The copper nanoparticle with smaller size,better dispersibility and narrow distribution of particle size can be obtained under the pH value of 0.5.The increase of pH value, the diameter of particle will change bigger.Copper nanoparticles appear serious aggregate under the pH value of 2.5.A quite ideal copper nanoparticle can be obtained under lower CuSO₄ concentration.While with increases in concentration of cupric sulphate,resulting in depression of the ionization and the weak repulsion force of surfactants,dissolving capacity of polar organic matter is greatly reduced.As a result, some copper nanoparticle is oxidized in high concentration of CuSO₄.The current density affects the size of the particles by influence on overpotential and the size of water droplet.A quite ideal copper nanoparticle can be obtained under the current density of 0.1 A/cm².