Morphological control of CaCO3 films with large area: Effect of additives and self-organization under atmospheric conditions

Hierarchically structured CaCO3 films were synthesized at atmospheric conditions (room temperature and 1 atm) without the use of templates or amphiphilic molecules in this process. The resulting CaCO3 film was formed by self-organization between Ca(OH)2 and aqueous CO2. The building blocks of the CaCO3 film were thought to be CaCO3 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 CaCO3 film, and the effects strongly depended on the type of additive and their concentrations. The additives used in this study decreased the crystallinity of CaCO3 (calcite) film in the order of glucose > aspartic acid > serine in a manner inversely proportional to the concentration of the additives. In addition, Mg2+, 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 CaCO3 film were found to be in the order of Na+ > K+ > Mg2+.

This figure shows schematic illustration for the formation of hierarchically organized CaCO3 film. The morphology control of CaCO3 film depends on a kind of additives.Figure optionsDownload high-quality image (83 K)Download as PowerPoint slideResearch highlights
► Hierarchically structured CaCO3 films are synthesized at atmospheric conditions (room temperature and 1 atm).
► The building blocks of the CaCO3 film are assembled with alignment and built into higher levels of structures.
► The soluble additives play a key role on the morphological control of CaCO3 film.