Preparation and in vitro bioactivities of calcium silicate nanophase materials

Abstract Nano-sized amorphous CaSiO 3 (A-CS) and β-wollastonite (β-CS) powder were produced by chemical precipitation method and subsequent heat treatment, using Ca(NO 3 ) 2 ·4H 2 O and Na 2 SiO 3 ·9H 2 O as the starting materials, polyethylene glycol as the dispersant. Bulk materials were produced using the two powders as precursors. Rough, porous, and elongated particles occurred in A-CS material and the grains of β-CS were smooth, dense, and spheric. The particle sizes of A-CS and β-CS were about 40 nm and 90 nm in diameter respectively. The bioactivities of A-CS and β-CS materials were investigated by soaking the two materials in SBF solution at 36.5 °C for 6 h to 15 days. Experiment results revealed that CaCO 3 crystallized accompanied with HAP on the A-CS surfaces. HAP crystallized constantly on the surfaces of β-CS. The HAP layer formed on β-CS was composed of uniformly sized particles. A layer of irregular particle size was formed on the A-CS owing to the co-existence of CaCO 3 . The A-CS showed a faster formation of HAP due to the high release rate of Ca ion.