Synthesis of Cu Nanoparticles Using Copper Carbonate as Cu Source Toward Versatile Applications.

Cu nanoparticles (NPs) coated with polyvinylpyrrolidone (PVP) were fabricated by polyol method using copper carbonate as a raw material. To increase the reaction temperature, glycol multimers such as diethylene glycol, triethylene glycol, or tetraethylene glycol were examined as a solvent. With increasing degree of multimerization, average diameter of Cu NPs decreased. The synthesis of Cu NPs was further investigated by changing reaction temperature, the amount and molecular weight of PVP in triethylene glycol as a solvent. Average diameter and standard deviation of Cu NPs were found to be highly dependent on those factors. As a result, fine Cu NPs ranging from 28 to 67 nm in average size with narrow size distribution (standard deviation: 16-28%) were obtained. The obtained Cu NPs were applied to a nanofluid, which showed higher thermal conductivity than the theoretical value. The antibacterial activity of Cu NPs was also demonstrated, and found to have strong antibacterial activity.