CHARACTERIZATION OF LIQUID AMORPHOUS CALCIUM CARBONATE PHASES BY IN SITU XAS

这个子项目是利用资源的许多研究子项目之一。 由NIH/NCRR资助的中心拨款提供。对子项目的主要支持 子项目的首席调查员可能是由其他来源提供的， 包括美国国立卫生研究院的其他来源。为子项目列出的总成本可能 表示该子项目使用的中心基础设施的估计数量， 不是由NCRR赠款提供给次级项目或次级项目工作人员的直接资金。 从饱和的碳酸氢钙溶液(即硬水)通过一种非常不常见的液体中间体形成碳酸钙(白垩石)，这种中间体非常稳定，而且是纳米级的，在中性pH下形成碳酸钙(这是活体动物或海水中矿物形成的典型)。该项目的目标是在原位表征沉淀过程中的机理和中间钙化合物。所采用的悬浮液滴技术可以在线监测碳酸钙的均匀结晶过程，同时避免任何可能通过非均相成核影响析出过程的外来相界。 了解经典生物矿物形成的基础知识对于仿生或生物启发的新材料以及骨植入物和骨/牙齿替代材料的开发至关重要。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. The formation of calcium carbonate (chalk) from a saturated calcium bicarbonate solution (i.e. hard water) proceeds at neutral pH (which is typical for the formation of minerals in living animals or sea water) via a very uncommon liquid intermediate, which is remarkable stable and nanosized. The goal of this project is to characterize in situ the mechanism and the intermediate calcium compounds which occur during this precipitation. The employed levitated droplet technique allows an in situ monitoring of the homogenous crystallization of calcium carbonate while avoiding any foreign phase boundaries that may influence the precipitation process by heterogeneous nucleation. Understanding the basics of classical biomineral formation is essential for biomimetic or bio-inspired new materials and for the development of bone implants and bone/teeth substitute materials.