Preparation of CaO-SiO2 glass-ceramic spheres by electrospraying combined with sol-gel method

Abstract

CaO-SiO2 glass-ceramic spheres were prepared by an electrospray method using hydrolyzed silicon alkoxide containing calcium nitrate. Crystalline calcium silicates, such as Ca2SiOand β-CaSiO formed around the surface of the spheres after heat treatment. The dissolution of the crystal phase of the spheres caused the release of Ca2+ and Si4+ ions during the initial stage of soaking in Tris-buffer solution, leading to the formation of nanosized pores at the sphere surface. The incorporation of Ca2+ ions into the glassy phase of the spheres suppressed the rapid pH increase during the initial stage of soaking in Tris-buffer solution. © 2013 Hirotaka Maeda et al.