Preparation and characterization of three-dimensional chrysanthemun flower-like calcium carbonate

Calcium carbonate with three-dimensional chrysanthemun flower-like structure was successfully prepared from calcium chloride and sodium carbonate ethanol/water mixed solution by a simple precipitation method, using trisodium citrate as crystal modifier. The experimental results show that the three-dimensional structure of chrysanthemun flower-like calcium carbonate is built up with several symmetrical micrometer multi-layer petals arranged around the multi-layer pancake-liked center, and the micrometer center and petals are assemblied by a large number of nanometer spherical particles with size 10-20 nm. It is found that the amount of trisodium citrate, the ethanol volume content has an important influence on the formation of this morphology. A possible mechanism is proposed to explain the formation of three-dimensional chrysanthemun flower-like calcium carbonate according the results. Scanning electron microscopy (SEM), X-ray powder diffraction (XRD), flourier transform infrared spectroscopy (FT-IR), thermogravimety analysis (TG), transmission electron microscopy (TEM) equipped with energy-dispersive X-ray (EDX), and selected area electron diffraction (SAED) were used to characterize the crystals.