Department of Chemical and Biomolecular Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon 305-701, Republic of Korea.
J Colloid Interface Sci. 2011 Mar 1;355(1):54-60. doi: 10.1016/j.jcis.2010.12.023. Epub 2010 Dec 14.
Hierarchically structured CaCO(3) films were synthesized at atmospheric conditions (room temperature and 1 atm) without the use of templates or amphiphilic molecules in this process. The resulting CaCO(3) film was formed by self-organization between Ca(OH)(2) and aqueous CO(2). The building blocks of the CaCO(3) film were thought to be CaCO(3) primary nanoparticles that aligned to build higher level structures with greater size, called mesocrystals, depending on the additives. The soluble additives played a key role in the control of the morphology, crystallinity, and polymorphism of the CaCO(3) film, and the effects strongly depended on the type of additive and their concentrations. The additives used in this study decreased the crystallinity of CaCO(3) (calcite) film in the order of glucose > aspartic acid > serine in a manner inversely proportional to the concentration of the additives. In addition, Mg(2+), K(+), and Na(+) ion additives led to the formation of an aragonite phase, the proportion of which increased with the concentration of ions. The threshold concentrations of these ions for the formation of the aragonite phase in CaCO(3) film were found to be in the order of Na(+) > K(+) > Mg(2+).
在此过程中，无需使用模板或两亲分子，在大气条件（室温及 1 个大气压）下即可合成具有层次结构的 CaCO3薄膜。所得 CaCO3薄膜是由 Ca(OH)2和水溶液中的 CO2之间的自组织形成的。认为 CaCO3薄膜的构建块是 CaCO3初级纳米颗粒，这些颗粒排列形成具有更大尺寸的更高层次结构，称为介晶，具体取决于添加剂。可溶性添加剂在控制 CaCO3（方解石）薄膜的形态、结晶度和多晶型方面起着关键作用，其影响强烈取决于添加剂的类型及其浓度。在这项研究中使用的添加剂按葡萄糖＞天冬氨酸＞丝氨酸的顺序降低 CaCO3（方解石）薄膜的结晶度，其降低程度与添加剂的浓度成反比。此外，Mg2+、K+和 Na+离子添加剂导致形成文石相，其比例随离子浓度的增加而增加。这些离子在 CaCO3薄膜中形成文石相的阈值浓度顺序为 Na+＞K+＞Mg2+。
