A biomimetic experimental study of magnesium ion mineralization in Mg-enriched aragonite
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In this work, we test the hypothesis that the Mg2+ content in biogenic aragonite has a systematic relationship with biomolecules. A series of biomimetic experiments were conducted to show the dependence of Mg2+ in aragonite on the model organic molecules added to the mineralizing solution, including the concentration of various organics, mineralization temperature, Mg/Ca ratio and Mg2+ initial concentration. The mineralized products were characterized by powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FESEM), thermogravimetric analysis (TGA), and inductively coupled plasma-atomic emission spectrometry (ICP-AES). High Mg2+ is detected in aragonite obtained in the presence of organics, whereas the lowest Mg2+ is measured in aragonite without organics. Moreover, the concentration of Mg2+ in aragonite increases gradually with the amended organics. Mg K-edge NEXAFS spectra show that the magnesium microenvironment in aragonite is similar to the organic-associated environment, indicating that the Mg2+ ions are not on the aragonite lattices, but adhere to the intracrystalline organics. Furthermore, the mineralization temperature, Mg/Ca ratio and Mg2+ content in mineralization medium significantly influence Mg2+ content in aragonite, reiterating the effect of the microenvironment on aragonite biomineralization.
KeywordsAragonite Magnesium content Organics Calcium carbonate Biomineralization
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This work was partially supported by the National Natural Science Foundation of China (Grant Nos. 41272054 and 41372053), and the Specialized Research Fund for the Doctoral Program of Higher Education (Grant No. 20133402130007).
- Finch A A, Allison N. 2008. Mg structural state in coral aragonite and implications for the paleoenvironmental proxy. Geophys Res Lett, 35: L08704Google Scholar
- Folk R L. 1974. Petrology of Sedimentary Rocks. Austin: Hemphill. 177Google Scholar
- Oomori T, Kaneshima K, Nakamura Y, Kitano Y. 1982. Seasonal variation of minor elements in coral skeletons. Galaxea, 1: 77–86Google Scholar
- Railsback L B, Brook G A, Chen J. 1994. Environmental controls on the petrology of a late Holocene speleothem from Botswana with annual layers of aragonite and calcite. J Sediment Res, 64: 147–155Google Scholar
- Zhou G T, Zheng Y F. 2001. Chemical synthesis of CaCO3 minerals at low temperatures and implication for mechanism of polymorphic transition. Neues Jb Miner Abh, 176: 323–343Google Scholar