2003 年 10 巻 303 号 p. 78-85
This paper investigated about synthesis and control of secondary particle size on hollow calcium carbonate, which was spherical aggregate of primary particle. The hollow calcium carbonate was synthesized by adsorbing calcium carbonate onto the octane droplet surface dispersed in calcium chloride solution. The sample was characterized by means of X-ray diffraction, scanning electron microscopy and infrared spectrometer.
The calcium carbonate was adsorbed onto the octane droplet surface including palmitic acid. This adsorption was based on-COOCa bonding formed by reaction of calcium ion of calcium carbonate and carboxylato ion of palmitic acid, which existed to the octane droplet surface. The modification of calcium carbonate adsorbed on the octane droplet surface was calcite and the primary particle size was approximate 0.1-0.3 μm. Also, hollow calcium carbonate has cavity inside. Repeating number controlled the wall thickness of hollow calcium carbonate. In the case of repeating number of 5, its wall thickness was about 1.3 μm. The average particle size of hollow calcium carbonate was adjusted from 7 to 18 μm by changing concentration of octane. The pore volume was increased with increase of wall thickness of hollow calcium carbonate with spherical.