Paper Title
Preparation of Nano-Silver Colloid Using Micro-Electrical Discharge Machining System

The Electrical Discharge Machining(EDM) can be used to prepare nanocolloid, and the method of preparing nanocolloid is called Electrical Spark Discharge Method(ESDM). Good nanocolloid can be prepared without any additives through the process of Electrical Spark Discharge. This study employed the Micro-Electrical Discharge Machining System to prepare nano-colloid, and the preparation of nano-silver colloid was taken as an example. In order to analyze the characteristics of nano-silver colloid, the UV-Visible Spectroscopy(UV-Vis), nanoparticle size and potential analyzer, X-ray diffractometer(XRD) and transmission microscope(TEM) were used for analyses. When the Ton-Toff was 30-30 μs, the Micro-Electrical Discharge Machining System(micro-EDM) could prepare nano-silver colloid which met the particle size and had good suspension property. The absorption peak of this colloid was 384nm, the absorbance was 0.237, the particle size was 35.55 nm, and the Zeta Potential was -32.2 mV. The analysis of the transmission microscope showed that the lattice width and particle size of silver particles were about 0.2389 and 24.84 nm respectively. According to the XRD analysis of the crystalline phase and characteristic peaks, the colloid was a silver material. Keywords - Electrical Spark Discharge Method, Dielectric Fluid, Silver nanoparticle, Zeta Potential