デンドリマー存在下で調製した炭酸カルシウム結晶の形態変化

Abstract

Calcium carbonate particles were prepared using solutions of CaCl 2 , urea, and poly(amidoamine)PAMAM dendrimers (G 1.5, G 3.5, and G5.5) with terminal carboxylates at 90°C. In the absence of dendrimers, uniform needle -like aragonite particles were formed, whereas when the concentration of dendrimers increased particles transformed to spherical vaterite. We used another method to obtain calcium carbonate particles from solutions containing CaCl 2 , urea, urease, and dendrimer at 25°C. Transmittance in the samples and X-ray diffraction measurements indicate that in the presence of dendrimer, at first vaterite particles are formed which then transform to calcite with the elapsed time, while in the absence of dendrimer only calcite particles are formed.