Chinese Journal of Applied Chemistry ›› 2015, Vol. 32 ›› Issue (7): 831-836.DOI: 10.11944/j.issn.1000-0518.2015.07.140413

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Control of Crystalline Polymorphs and Morphologies for Calcium Carbonate with Sodium Citrate

GAO Yanfang, WANG Haishui*   

  1. School of Chemistry and Chemical Engineering,South China University of Technology,Guangzhou 510640,China
  • Received:2014-12-02 Accepted:2015-03-27 Published:2015-06-30 Online:2015-06-30
  • Contact: Haishui WANG
  • Supported by:
    Supported by the National Natural Science Foundation of China(No.20873136)

Abstract:

Calcium carbonate with various polymorphs and morphologies was prepared by urea hydrolytic method in this study. The crystals were characterized by powder X-ray diffraction (XRD) and scanning electron microscopy (SEM) analysis. Uniform needle-like aragonite crystals are obtained in aqueous solution at 90 ℃. In contrast, the addition of sodium citrate results in the formation of novel morphologies of calcite crystals. We also studied the growth of calcium carbonate in the mixed solvent of ethanol/water with sodium citrate as control agent. The results show that sodium citrate also has significant influence on polymorphs and morphologies of calcium carbonate in the ethanol/water mixed solution. Hollow spherical vaterite crystals are obtained in the presence of sodium citrate by changing the volume fraction of ethanol.

 

Key words: calcium carbonate, polymorphs, sodium citrate, ethanol/water mixed solutions, urea

CLC Number: