Electrophoretic Deposition of Ceramic Nanoparticles

An electrophoretic deposition (EPD) method has been developed for the deposition of nanostructured zinc oxide (ZnO) and TiO2 films. It was shown that the stabilization and charging of the nanoparticles in suspensions can be achieved using organic molecules, such as dopamine and alizarin yellow (AY) dye, which were adsorbed on the oxide nanoparticles. Fourier-transform infrared spectroscopy investigations showed that the adsorption mechanism is based on the complexation of metal ions at the surfaces of oxide nanoparticles. Cationic dopamine additive was used for the formation of deposits by cathodic EPD. The adsorption of anionic AY on the oxide nanoparticles resulted in charge reversal and enabled the formation of anodic deposits. The method enabled the codeposition of ZnO and TiO2 and the formation of composite films. It was shown that the deposition yield and deposit composition can be controlled by the variation of deposition time and suspension composition. The deposits were studied using X-ray diffraction and electron microscopy. The deposition mechanism and kinetics of deposition are discussed.