Effects of initial supersaturation on spontaneous precipitation of calcium carbonate in the presence of charged poly-l-amino acids

Njegić-Džakula, Branka; Falini, Giuseppe; Brečević, Ljerka; Skoko, Željko; Kralj, Damir

doi:10.1016/j.jcis.2009.12.010

Cited by 74 publications

(94 citation statements)

References 46 publications

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“…8B). SEM demonstrated that these birefringent particles had a corrugated spherical morphology characteristic of vaterite (39) (Fig. 8C and SI Appendix, Fig.…”

Section: Resultsmentioning

confidence: 99%

A classical view on nonclassical nucleation

Smeets

Finney

Habraken

et al. 2017

Proc. Natl. Acad. Sci. U.S.A.

217

212

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Understanding and controlling nucleation is important for many crystallization applications. Calcium carbonate (CaCO 3 ) is often used as a model system to investigate nucleation mechanisms. Despite its great importance in geology, biology, and many industrial applications, CaCO 3 nucleation is still a topic of intense discussion, with new pathways for its growth from ions in solution proposed in recent years. These new pathways include the socalled nonclassical nucleation mechanism via the assembly of thermodynamically stable prenucleation clusters, as well as the formation of a dense liquid precursor phase via liquid-liquid phase separation. Here, we present results from a combined experimental and computational investigation on the precipitation of CaCO 3 in dilute aqueous solutions. We propose that a dense liquid phase (containing 4-7 H 2 O per CaCO 3 unit) forms in supersaturated solutions through the association of ions and ion pairs without significant participation of larger ion clusters. This liquid acts as the precursor for the formation of solid CaCO 3 in the form of vaterite, which grows via a net transfer of ions from solution according to z Ca 2+ + z CO 3 2− → z CaCO 3 . The results show that all steps in this process can be explained according to classical concepts of crystal nucleation and growth, and that long-standing physical concepts of nucleation can describe multistep, multiphase growth mechanisms.calcium carbonate | nucleation | crystal growth | cryo-electron microscopy | molecular simulation I n the process of forming a solid phase from a supersaturated solution, nucleation is the key step governing the timescale of the transition. Controlling nucleation is an essential aspect in many crystallization processes, where distinct crystal polymorphism, size, morphology, and other characteristics are required. It is, therefore, important to obtain a fundamental understanding of nucleation mechanisms.More than 150 years ago, a basic theoretical framework, classical nucleation theory (CNT) (1, 2), was developed to describe such nucleation events. CNT describes the formation of nuclei from the dynamic and stochastic association of monomeric units (e.g., ions, atoms, or molecules) that overcome a free-energy barrier at a critical nucleus size and grow out to a mature bulk phase. Calcium carbonate (CaCO 3 ) is a frequently used model system to study nucleation (3-5); however, despite the many years of effort, there are still phenomena associated with CaCO 3 crystal formation where the applicability of classical nucleation concepts have been questioned (6). These include certain microstructures and habits of biominerals formed by organisms (7), or geological mineral deposits with unusual mineralogical and textural patterns (8).Three anhydrous crystalline polymorphs of CaCO 3 are observed in nature: vaterite, aragonite, and calcite in order of increasing thermodynamic stability. In many cases, the precipitation of CaCO 3 from solution is described as a multistep process, with amorphous phases first pr...

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“…8B). SEM demonstrated that these birefringent particles had a corrugated spherical morphology characteristic of vaterite (39) (Fig. 8C and SI Appendix, Fig.…”

Section: Resultsmentioning

confidence: 99%

A classical view on nonclassical nucleation

Smeets

Finney

Habraken

et al. 2017

Proc. Natl. Acad. Sci. U.S.A.

217

212

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“…It is known that ACC is transformed to more stable calcium carbonate modifications by a so-called solution mediated transformation, which comprises processes of simultaneous dissolution of ACC and nucleation and crystal growth of the more stable modifications, calcite or vaterite. 33,34 However, in the presence of certain macromolecules, like natural glycoproteins and polysaccharides or synthetic polymers and even magnesium ions, ACC can be stabilized due to inhibition of its dissolution. 35,36 Giles et al 37 found that the dissolution of Ca(OH) 2 at low stirring rate is controlled by the diffusion of calcium and hydroxide ions away from the surface, while the dissolution is surface controlled at an intensive stirring.…”

Section: Resultsmentioning

confidence: 99%

Synthesis of Calcium Carbonate by Semicontinuous Carbonation Method in the Presence of Dextrans

Kontrec¹,

Ukrainczyk²,

Babić-Ivančić³

et al. 2011

Croat. Chem. Acta

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Abstract. Precipitated calcium carbonate (PCC) was prepared by means of semicontinuous carbonation of Ca(OH) 2 suspension, at 35 and 45 °C and in the presence of non-ionic dextran and dextran sulfate. The carbonation process was regulated at different predetermined values of electrical conductivity, that corresponded to different concentrations of dissolved Ca(OH) 2 : 0.5 mS cm. The results of physicalchemical characterization of the product showed that calcite was the only polymorphic modification obtained in the whole range of experimental conditions investigated. In addition, it was found that morphology, crystal size distribution and specific surface area of PCC strongly depended on the electrical conductivity / concentration of dissolved Ca(OH) 2 , at which the process was performed: predominantly scalenohedral crystals of higher surface area (about 5 m 2 g −1) were produced at higher electrical conductivity, while at lower electrical conductivity predominantly rhomohedral calcite crystals of relatively low specific surface area were obtained. In the system of the highest electrical conductivity, κ 25 = 5.0 mS cm, and at 35 °C, the addition of non-ionic dextran significantly influenced the process by preventing the regulation. The crystals that appeared were in the form of irregular aggregates of high specific surface area, S ≈ 29 m 2 g −1. FT-IR and TG analyses indicated that the non-ionic dextran was adsorbed onto the calcite surface, most probably by relatively strong and specific interactions between oxygen from the hydroxyl groups of dextran molecules and calcium ions from the crystal surface. On the contrary, the anionic dextran (dextran sulfate) exerted minor effects in the course of semicontinuous carbonation process and in the properties of the final product, PCC. However, the analysis of the precipitate indicated that dextran sulfate was adsorbed at the surfaces, most probably by the weak and non-specific electrostatic interactions. (doi: 10.5562/cca1746)

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“…Thus, carboxylate functions seem to be beneficial for impeding nucleation, which is reasonable when considering that most industrial scale inhibitors are based on polyacrylates or consist of pure poly(aspartic acid) [52]. Also, poly-L-aspartic acid, poly-L-glutamic acid and poly-L-lysine were reported to be nucleation inhibitors for CaCO 3 with the degree of delay increasing according to pAsp > pGlu ) pLys [53].…”

Section: Time Of Nucleationmentioning

confidence: 97%

The multiple effects of amino acids on the early stages of calcium carbonate crystallization

Picker¹,

Kellermeier²,

Seto³

et al. 2012

Zeitschrift Für Kristallographie - Crystalline Materials

109

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Abstract. Proteins have found their way into many of Nature's structures due to their structural stability, diversity in function and composition, and ability to be regulated as well as be regulators themselves. In this study, we investigate the constitutive amino acids that make up some of these proteins which are involved in CaCO 3 mineralization -either in nucleation, crystal growth, or inhibition processes. By assaying all 20 amino acids with vapor diffusion and in situ potentiometric titration, we have found specific amino acids having multiple effects on the early stages of CaCO 3 crystallization. These same amino acids have been independently implicated as constituents in liquid-like precursors that form mineralized tissues, processes believed to be key effects of biomineralization proteins in several biological model systems.

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Effects of initial supersaturation on spontaneous precipitation of calcium carbonate in the presence of charged poly-l-amino acids

Cited by 74 publications

References 46 publications

A classical view on nonclassical nucleation

A classical view on nonclassical nucleation

Synthesis of Calcium Carbonate by Semicontinuous Carbonation Method in the Presence of Dextrans

The multiple effects of amino acids on the early stages of calcium carbonate crystallization

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