title: Preparation and structure evolution of bowknot-like calcium carbonate particles in the presence of poly(sodium 4-styrene sulfate).
abstract: Calcium carbonate particles with a novel bowknot-like superstructure were fabricated in the presence of poly(sodium 4-styrene sulfate) (PSS) and under the assistance of ultrasonication during the initial reaction stage. X-ray powder diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, transmission electron microscopy (TEM), selected area electron diffraction (SAED), and field-emission scanning electron microscopy (FE-SEM) equipped with energy-dispersive X-ray (EDX) were used to characterize the particles. Results demonstrated that the bowknot-like calcium carbonate particles were mainly composed of amorphous calcium carbonate (ACC) and some amounts of calcite and vaterite. Ultrasound irradiation associated with the presence of PSS affects the mesoscale crystallization, resulting in stepwise growth of the earlier bundles to the bowknot. Morphology evolution and dissolution of the bowknot particle were observed in different media, confirming that PSS and Ca(2+) ions in the solutions could accelerate and resist the transformation process, respectively. In the presence of PSS, ACC prefers to transform into vaterite.
authors.affiliation: MOE of Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou 310027, China.
authors.forename: Lili
authors.initials: L
authors.lastname: Xie
authors.forename: Xiaoxue
authors.initials: X
authors.lastname: Song
authors.forename: Weijun
authors.initials: W
authors.lastname: Tong
authors.forename: Changyou
authors.initials: C
authors.lastname: Gao
mesh_terms: D002119:Calcium Carbonate / Q000737:chemistry*; D011137:Polystyrenes / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods; D014961:X-Ray Diffraction / Q000379:methods
chemical_list: D011137:Polystyrenes; C071389:polystyrene sulfate; D002119:Calcium Carbonate