Oriented Vaterite CaCO3 Tablet-Like Arrays Mineralized at Air/Water Interface through Cooperative Regulation of Polypeptide and Double Hydrophilic Block Copolymer

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• 作者：Xinran Liu ; Bianhua Liu ; Zhenyang Wang ; Buchang Zhang ; Zhongping Zhang
• 刊名：Journal of Physical Chemistry C
• 出版年：2008
• 出版时间：July 3, 2008
• 年：2008
• 卷：112
• 期：26
• 页码：9632 - 9636
• 全文大小：1957K
• 年卷期：v.112,no.26(July 3, 2008)
• ISSN：1932-7455

文摘

Highly oriented vaterite CaCO₃ tablet-like arrays were formed at the air/water interface through the cooperative mineralization regulated by polypeptide and double hydrophilic block copolymer under ambient conditions. The nearly parallel arrangement of CaCO₃ vaterite tablets at the air/water interface shows the remarkable resemblance to the morphology of nacreous layers. The poly(aspartic acid) (PASP) with high molecular weight (M_w = 11 000) and low solubility in water promoted the formation of vaterite tablets at the air/water interface, and stabilized the vaterite tablets by aggregation at the air/water interface and adsorption at the surface of vaterite tablets. Meanwhile, the highly hydrophilic poly(ethylene glycol)-block-poly(methacrylic acid) (PEG-b-PMAA) played an important role in regulating the arrangement and orientation of vaterite CaCO₃ tablets, leading to the oriented tablet-like arrays at the air/water interface. Detailed experiments revealed that hydrophilic PEG-b-PMAA alone did not produce any form of CaCO₃ crystals at the air/water interface, but could induce the formation of calcite CaCO₃ particles in the water phase. However, high molecular weight PASP alone led to the formation of disk-like vaterite particles composed of helically aggregated nanoplates at the air/water interface, suggesting the regulating role of PEG-b-PMAA in the growth of vaterite tablet arrays. These results reported here provide a better understanding of the growth mechanism of nacreous layers and shells in nature.