Ultra-Low-Power Electrophoretic Deposition of Silica Powder with Nonflammable Organic Solvent

Abstract

Although conventional organic solvents are used in electrophoretic deposition (EPD) owing to several advantages, they are hazardous because of their inflammability or ignition properties. In contrast, hydrofluoro ether (HFE) is nonflammable, polar and possesses excellent electrical insulation properties. In this study, methoxy-nonafluorobutane (MNFB), which is one of HFE was used as the solvent for the EPD of silica powder. Because the density of MNFB is larger than water, sedimentation of inorganic particles is slow. The deposition behavior in MNFB was similar to the EPD in conventional solvents, and was controlled by tuning the applied voltage, deposition time, and particle concentration. A uniform coating was obtained. Notably, the power consumed in this process was significantly lower than that in the EPD using conventional solvents. The current density was of the order of 10 nA/cm2; therefore, the electric power consumption for EPD using MNFB was less than 0.1% of those using conventional solvents. Therefore, MNFB can be used as an effective solvent for EPD because it is nonflammable, allows the application of high voltage, and enables the deposition of particles with low power consumption.