Uniform and ultra low-power electrophoretic deposition of silica powder using a nonflammable organic solvent

Conventional organic solvents used for electrophoretic deposition (EPD) exhibit several advantages such as high electrical resistance, zero bubble formation, and the feasibility of using high voltages. However, they can be hazardous because of their high inflammability or low ignition temperatures. In this study, methoxy-nonafluorobutane (MNFB) was used as a solvent for the EPD of silica powder. MNFB is nonflammable, polar, and possesses excellent electrical insulation properties. The density of MNFB is greater than that of water, and therefore, the sedimentation of inorganic particles in MNFB is slow. As a result, a uniform coating was obtained. The deposition behavior in MNFB was similar to that observed during EPD in conventional solvents. Further, the deposition of silica could be controlled by deposition time using high voltages. The power consumed during the process was less than 0.1% of that used during EPD with conventional solvents. Therefore, MNFB is an effective solvent for EPD.