Facile Self-Assembly Synthesis of Hierarchical 3D Flowerlike Calcium Citrate Microspheres

Three-dimensional (3D) flowerlike calcium citrate microspheres assembled from nanosheets were successfully synthesized through a soft chemical method. The phase structure, morphology and microstructure of the synthesized products were characterized by the SEM, XRD, infrared and Raman spectroscopy. The characterization results indicated that the well-organized products with the diameter ranging from 10 to 30 mu m were composed of nanosheet precursors (50 similar to 500nm-50 similar to 200nm-8 similar to 30nm). The (200) crystal plane was the preferential growth face in the self-assembly process and the sheet precursors could be progressively transformed into consecutive strip with continuous heating treatment. The novel flowerlike calcium citrate microspheres with controllable morphology shows potential application prospect in biomaterials or other fields.