writer：Qi Li, Lijie Dong, Wei Deng, Qingming Zhu, Yun Liu, Chuanxi Xiong
keywords：CaCO3 NPs，solvent-free nanofluid，nanostructures
source：期刊
Issue time：2009年
It is reported that the aqueous slurry of CaCO3 NPs has a basic pH of 9.4, and under ambient conditions, CaCO3 has OH groups on the surface. The pH value was adjusted to 10-12 in our synthesis procedure so that more OH groups would be attached to the incompletely coordinated calcium ions on the surface, and a basic pH of ∼10.5 was proven to be favorable in promoting the condensation of OH groups on other inorganic particles surfaces. By investigating the X-ray photoelectron spectroscopy (XPS) of C1s and Ca2p core levels from CaCO3 NPs both before and after adjusting the pH value, we found surface differences in the two cases. Under an adjusted pH value, we successfully synthesized the solvent-free fluids based on CaCO3 NPs in a facile and user friendly method. Since we can only obtain a solid-like product based on CaCO3 NPs without adjusting the pH value, it can be concluded that the pH adjustment is effectual.