http://www.ugr.es/~grupo179/pdf/Rodriguez%20Navarro%20C%2007.pdf

Bacterially mediated mineralization of vaterite

We demonstrate nanoscale architectures in real biominerals and their biomimetics. Mimicking biomineralization, that is, crystal design in association with organic molecules, has been demonstrated in recent years. Although the macroscopic morphologies in real biominerals and biomimetics have been extensively studied, the nanoscopic structures in terms of the crystal growth are still not fully understood. We show that both materials form oriented architectures of bridged nanocrystals with incorporated organic polymers. The growth of nanocrystals by association with polymers is a significant step for the understanding and developing of crystal growth. The strategy could be applied to various systems in nanoscale crystal growth leading to functional materials.

Bridged Nanocrystals in Biominerals and Their Biomimetics: Classical Yet Modern Crystal Growth on the Nanoscale†

In recent years, the prevalence of hydrogel-like organic matrices in biomineralization has gained attention as a route to synthesizing a diverse range of crystalline structures. Here, examples of hydrogels in biological, as well as synthetic, bio-inspired systems are discussed. Particular attention is given to understanding the physical versus chemical effects of a broad range of hydrogel matrices and their role in directing polymorph selectivity and morphological control in the calcium carbonate system. Finally, recent data regarding hydrogel-matrix incorporation into the growing crystals is discussed and a mechanism for the formation of these single-crystal composite materials is presented.

Crystal Growth of Calcium Carbonate in Hydrogels as a Model of Biomineralization

https://digital.csic.es/bitstream/10261/66230/4/carbonation_calcium_Lopez.pdf

Influence of relative humidity on the carbonation of calcium hydroxide nanoparticles and the formation of calcium carbonate polymorphs

Raman spectroscopy was used to study vaterite samples of biological, geological and synthetic origin. The Raman band positions and the full width at half-maximum (FWHM) of the lattice modes and the internal modes of the carbonate ion of all specimens show no significant differences between vaterites of different origin. With increasing Mg concentrations, synthetic vaterite samples show increasing FWHM in the region of the lattice modes and the three ν1 bands, whereas no change in luminescence was detected. In contrast, in situ measurements of vaterite areas in freshwater cultured pearls (FWCPs) by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) together with the Raman spectra obtained at the same points show that the luminescence intensity in biological samples is affected by the magnesium content. The Raman spectroscopic features of vaterite and parisite-(Ce) are compared, and their similarities suggest that the structure of vaterite contains at least three crystallographically independent carbonate groups and similar carbonate group layers. A band at 263 cm−1 is observed for the first time in this study, whereas it could be demonstrated that bands previously reported at 130 and 190 cm−1 do not belong to vaterite. Copyright © 2009 John Wiley & Sons, Ltd.

Raman spectroscopy of synthetic, geological and biological vaterite: a Raman spectroscopic study

Calcium carbonate polymorphism is one of the most challenging problems in biomineralization. Calcium carbonate exists in three crystalline forms: calcite, aragonite and vaterite. Otoliths of teleost fishes are made of vaterite and aragonite, located in different sacs and never mixed together. This paper presents a biochemical characterization of the intracrystalline macromolecules associated to the vateritic and aragonitic phases of otoliths. Experimental evidences from cal

/pdf/influence-on-the-formation-of-aragonite-or-vaterite-by-i3gm36ak7g.pdf

Giulia Zaffino

Papers

Influence on the Formation of Aragonite or Vaterite by Otolith Macromolecules