シリカゲルからのSiO₂-ZrO₂-CaO-Na₂O組成の多孔性微小球状粒子の合成

抄録

Preparation of porous microspheres in the SiO₂-ZrO₂-CaO-Na₂O system was investigated by heating a mixture of fine Na₂CO₃ powder and commercially available, microspherical silica gel impregnated with ZrOCl₂ and CaCl₂, and by subsequently washing the product with water. Porous microspheres, whose surface was composed of sponge-like skeletons were obtained; their pore volume was up to 0.59cm³·g^-1 and the mode pore radius was in the range between 23 and 38nm. The composition of the porous microspheres was SiO₂-ZrO₂-CaO-Na₂O, which contained ZrO₂ in the range between 11 and 17mass%. Almost all amounts of Ca and Zr added and a certain amount of Na remained in the porous microspheres. Addition of CaCl₂ resulted in a more homogeneous distribution of ZrO₂ and an increase in resistance to alkaline solution, compared to those of the microspheres prepared by the same procedure without CaCl₂ addition.