Electrophoretic deposition of titanium dioxide using organic acids as charging additives

Electrophoretic deposition (EPD) of TiO2 was performed from suspensions in ethanol using organic acids as dispersing agents. Anodic deposition was achieved using caffeic acid (CA). Cathodic deposition was performed using 2,4 dihydroxycinnamic acid (DCA), p-coumaric acid (PCA) and trans cinnamic acid (TCA). The adsorption of the organic molecules was studied by Fourier transform infrared spectroscopy (FTIR). CA showed catecholate type of bonding which enabled strong adsorption on TiO2 nanoparticles. The organic molecules provided good dispersion and charging of TiO2 particles for application in EPD. The deposition yield can be varied and controlled. The charging mechanism is discussed.