Preparation and Characterization of Silver Citrate Nano-emulsion and Nano-silver Film

摘要

To prepare the nano-scale silver carboxylate emulsions and investigate their applications in the preparation of nano-scale silver films, the silver citrate emulsion was synthesized through the reaction of silver nitrate with sodium citrate in the presence of polyvinylpyrrolidone (PVP) as a surface modification agent in water. The emulsion was coated onto the surface of the PET substrate to form a thin latex layer of silver citrate. And this was followed by drying at about 100 ℃. Then, the silver citrate thin film was deoxidized by aqueous ascorbic acid. Finally, a translucent silver thin film was formed on the surface of the PET substrate. Properties of the silver citrate emulsion and the silver film on the PET were characterized by X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), laser particle size analysis, scanning electron microscopy (SEM), thermogravimetry(TG) ,UV-visible absorption spectroscopy, atomic force microscopy(AFM) and digital multimeter analysis. It was found that the silver citrate particle surface-modified by PVP has a nano-rod structure and homogeneous size distribution. The nano-rod was about 20 nm in diameter and 200 nm in length. For the UV-visible absorption spectrum of the thin film exhibited an absorption peak at 430 nm, the silver thin film prepared on the surface of the PET substrate was a typical nano-scale sliver film. Measurements of the sliver thin film at room temperature indicated that the silver film was electrically conductive, and the surface resistance was 2.42 kΩ/cm.