For increasing thermoelectric properties, making core-shell structure of alumina and thermoelectric material was studied. As the first step of this study, the nano alumina particle was dispersed in D. I. water and ethylene glycol without dispersant. The concentration of alumina and other enhanced methods were adapted in water and ethylene glycol respectively. In D. I. water, the dispersion of alumina was related to the alumina concentration and the re-dispersion was also possible by ultrasonic homogenizer. However, in the case of ethylene glycol, the mean particle size wasn't changed by the enhanced dispersion methods. After the dispersion, the mean particle size was changed significantly during the short keeping time. As a whole, the mechanical dispersion of alumina in ethylene glycol was possible in a few second. And, in the experiment of dispersion stability by the addition of commercial dispersants, the slurry using D. I. water has kept under submicron for a month. However, in the case of ethylene glycol, particles were coagulated for a moment regardless of the kind of dispersion agent.

Keywords: Mechanical dispersion; Nano Particles; Alumina; Solvent