Polymorph Control of Calcium Carbonate Using Insoluble Layered Double Hydroxide

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• 作者：Arpita Sarkar ; Kingshuk Dutta ; Samiran Mahapatra
• 刊名：Crystal Growth & Design
• 出版年：2013
• 出版时间：January 2, 2013
• 年：2013
• 卷：13
• 期：1
• 页码：204-211
• 全文大小：606K
• 年卷期：v.13,no.1(January 2, 2013)
• ISSN：1528-7505

文摘

This paper demonstrates crystallization of calcium carbonate in the presence of insoluble Mg鈥揂l layered double hydroxides (LDH). The metastable aragonite phase is preferentially stabilized over the thermodynamically more stable calcite phase in the presence of this insoluble inorganic matrix at ambient temperature. Such aragonite particles possess an unconventional 鈥渞osette-like鈥?morphology. In the intermediate stages of crystallization, another metastable phase, vaterite, having a 鈥渇laky-floret-like鈥?morphology, is initially formed, and an unusual transformation of 鈥榲aterite to aragonite鈥?is observed. The kinetics of such a transformation is systematically studied and captured through their crystal characterization. The presence of Mg-rich layers and the surface hydroxyl groups in LDH is postulated as one of the probable factors for such phase selectivity. The role of 鈥渟oluble鈥?Mg²⁺ ions in affecting polymorph selectivity is ruled out based on the very low concentration of Mg²⁺ ions leaching out of LDH. This is the first report of the use of Mg鈥揂l LDH as an 鈥渋nsoluble inorganic material鈥?to promote polymorph selectivity in calcium carbonate. This can also have potential significance in biomineralization.