Effects of different particle sizes of titanium dioxide on electrophoretic mobility were investigated. Methodology to synthesize different sizes of titaniumdioxide were carried outwith varyingmolar ratio, wo ï»[H2O]/[Surfactant] values,which later hydrolyzed byTetrapropyl orthotitanate (TPOT) based with sol-gel microemulsions techniques. Synthesized TiO2 demonstrated the increase in sizes as the molar ratio of water over surfactant increased. Electrophoretic mobility of TiO2 with different sizes was measured in different pH range from4 to 10, temperatures from150Cto 600C and applied voltages varied from10Vto 60V. Results showed that the optimum electrophoretic mobility was observed at pH 6 for all the particles sizes. Buffer for pH 6 with less hydrogen ion increased the electrophoretic mobility. Meanwhile, electrophotic mobility of TiO2 at temperatures below 600C did not show any significant changes for all sizes of particles, unless 600C. This indicated that higher temperatures increased kinetic energy of charged particleswhich led to a random movement of particles and reduced electrophoretic mobility. In different applied voltages, the electrophoretic mobility of the biggest size of TiO2 increased propotionally as increase in voltages. The higher applied voltage provided a greater electrostatic force to the particles. The smallest size of TiO2 recorded higher electrophoretic mobility. This indicated that the smallest TiO2 possessed denser negative charges on its surface and experienced lesser frictional force contributed to greater mobility.