Synthesis of Cu–SiO 2 Core–Shell Using Ultrasonic Waves and Its Antibacterial Activity

In this study, we compared the final core–shell products produced in the presence or absence of ultrasonic waves and evaluated the antibacterial properties of the core–shell. When ultrasonic wave was used, a complete core–shell structure with a silica shell coated on an individual core particle could be observed. Transmission electron microscopy and energy dispersive X-ray spectroscopy were performed to confirm the shape of the core–shell structure formed in each case. In order to evaluate the antibacterial activity of the core–shell with the Cu core, their antibacterial activity was evaluated by the KS J 4206 and JIS Z 2801. The Cu–SiO 2 core–shell showed a high level of microbial reduction and it also worked as filler in the glass powder.