Research on the Synthesis of Nanocomposite Colloids by Micro EDM

In this study, a micro electrical discharge machine (micro-EDM) was employed to fabricate zinc oxide–titanium dioxide (ZnO–TiO₂) nanocomposite colloids using the Electrical Spark Discharge Method (ESDM) in a deionized water dielectric. High-purity (99.99%) zinc and titanium wires were used as electrodes, and the discharge process was conducted under ambient temperature and atmospheric pressure conditions. Systematic experiments were performed to investigate the effects of various discharge pulse parameters (Ton–Toff) and discharge voltages. The particle size and zeta potential of the colloids were measured using a laser scattering particle size analyzer (Zetasizer), and their optical properties were characterized with a UV-Visible (UV-Vis) spectrophotometer. The results showed that the colloid fabricated under a Ton–Toff of 50–50µs and a discharge voltage of 160V exhibited the best suspension stability, achieving a zeta potential of 29.8mV and an average particle size of approximately 76.57nm. Overall, this study confirms that ESDM enables the rapid and environmentally friendly synthesis of high-purity nanocomposite colloids without the need for chemical additives, demonstrating significant potential for applications in biomedical materials and environmental fields.