Electrophoretic Deposition of Nanosized Diamond Particles

Abstract

Diamond nanoparticles deposited by electrophoretic deposition (EPD) were investigated by several microscopic techniques. We have demonstrated that EPD method is useful to deposit nanosized diamond particles from isopropyl alcohol suspensions on highly oriented pyrolytic graphite (HOPG) substrates. These nanoparticles acquire a negative surface charge in aqueous and organic suspensions. However, in isopropyl alcohol suspensions, H+ ions generated in situ by reaction between iodine and acetone are adsorbed on the diamond particles, resulting in a positive surface charge. Observation of the surface of both cathode and anode confirms that diamond particles are mainly deposited on cathode. Deposits at very low concentration exhibit a seeding of nanoparticles. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) pictures showed that the deposited diamond nanoparticles are separate and have a spherical shape. It was also established that the defect sites, such as steps on HOPG surface, are favorable for the deposition of particles.