Preparation of Thermal Insulator of Silica from Waterglass Using Electrophorectic Deposition

摘要

Thermal insulating material was prepared by electrophoretic deposition of nanosilica from sodium silicate in a mixture of water and ethanol. The as-prepared silica powders have the surface area ranged from 138.53 to 338.81 m~2/g and the pore volume from 0.57 cm~3/g to 0.74 cm~3/g, depending on the applied electric field intensity and the solvent composition. The thermal conductivity of the porous silicas ranged from 0.75 to 3.61 W/m?K., depending on the porosity of the silicas. The higher the porosity is, the lower the thermal conductivity is.