title: Catanionic surfactant-assisted mineralization and structural properties of single-crystal-like vaterite hexagonal bifrustums.
abstract: Crystalline vaterite is the most thermodynamically unstable polymorph of anhydrous calcium carbonate (CaCO3), and various morphologies can be controlled in the presence of organic additives. Constructing vaterite with minimal defects, determining its distinctive properties, and understanding the formation mechanism behind a biomimetic process are the main challenges in this field. In this paper, a unique single-crystal-like vaterite hexagonal bifrustum with two hexagonal and 12 trapezoidal faces has been fabricated through a catanionic surfactant-assisted mineralization approach for the first time. Compared with the polycrystalline vaterite aggregates, these bifrustums clearly present a doublet for Raman v1 symmetric stretching mode, a low depolarizaiton ratio for carbonate molecular symmetry, and a high structural stability. These indicate a dominant position of hexagonal phase in each crystallite and confirm the Raman v1 doublet characteristics of synthetic and biomineral-based vaterites. Our finding may provide evidence to distinguish vaterite with different structures and shed light on a possible formation mechanism of vaterite single crystals.
authors: Key Laboratory for Colloid and Interface Chemistry of Education Ministry, School of Chemistry & Chemical Engineering, Shandong University , Jinan 250100, China.
authors: Rui
authors: R
authors: Liu
authors: Fenglin
authors: F
authors: Liu
authors: Yunlan
authors: Y
authors: Su
authors: Dujin
authors: D
authors: Wang
authors: Qiang
authors: Q
authors: Shen
mesh_terms: D000641:Ammonia / Q000737:chemistry; D002119:Calcium Carbonate / Q000138:chemical synthesis / Q000737:chemistry*; D002412:Cations / Q000737:chemistry; D015394:Molecular Structure; D010316:Particle Size; D013499:Surface Properties; D013501:Surface-Active Agents / Q000737:chemistry*
chemical_list: D002412:Cations; D013501:Surface-Active Agents; D000641:Ammonia; D002119:Calcium Carbonate