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无形CaCO3:形成时间对其水分和稳定程度的影响
Huachuan Du1, Mathias Steinacher1, Camelia Borca2
1Soft Materials Laboratory , Institute of Materials, École Polytechnique Fédérale de Lausanne (EPFL) , 1015 Lausanne , Switzerland.
Journal of the American Chemical Society
|September 29, 2018
概括
研究人员开发了一种研究无形碳酸 (ACC) 形成的新方法. 较大的ACC颗粒含有更多的水,使它们不太稳定,但PAA等添加剂可以提高稳定性.
科学领域:
- 材料科学
- 生物矿物化
- 化学工程
背景情况:
- 碳酸 (CaCO3) 在自然界中大量存在,并用于海洋结构,具有卓越的机械性能.
- 了解CaCO3形成是复制这些特性在合成材料的关键.
- 目前的方法缺乏时间分辨率来研究早期的无形CaCO3 (ACC) 形成.
研究的目的:
- 在早期形成阶段研究无形碳酸 (ACC) 颗粒的结构和组成的演变.
- 开发一种新的,无有机溶剂的方法来进行高分辨率的时间研究.
- 阐明移动水含量在ACC粒子稳定性和转化中的作用.
主要方法:
- 使用微流体喷雾干燥器在空气中产生ACC颗粒.
- 控制的粒子形成时间从100ms到10s,允许高时间分辨率的火.
- 使用各种表征技术分析了粒子大小,移动水含量和稳定性之间的关系.
主要成果:
- 证明较大的ACC粒子在较长时间内形成, 含有更多的移动水.
- 显示较高的移动水含量降低了对温度诱导的结晶和电子束分解的粒子稳定性.
- 证实使用多烯酸 (PAA) 等有机添加剂可以减少水的流动性,并提高动力稳定性.
结论:
- 建立了形成时间,颗粒大小,移动水含量和无形碳酸稳定性的联系.
- 确定移动水是影响ACC固态转化途径的关键因素.
- 突出了使用添加剂控制ACC稳定性的潜力,为制造具有定制性质的仿生CaCO3材料铺平了道路.
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