The monoclinic I2 structure of bassanite, calcium sulphate hemihydrate (CaSO4 0.5H2O)

Ballirano, Paolo; Maras, Adriana; Meloni, Simone; Caminiti, Ruggero

doi:10.1127/0935-1221/2001/0013/0985

Cited by 81 publications

(65 citation statements)

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“…It is worthy noting that, as recent reports also do, when nanocrystals of bassanite are obtained, 5 we always refer to the generic term of bassanite (including subhydrates) as assignation is extremely difficult beyond reasonable doubt in nanocrystals. 40,41 Compositions with SrCl 2 and the lowest oleate content (OL2) lead to the typical bassanite nanofibers ( Figure 1A) associated with gypsum formation via nanofiber intermediates ( Figure 2). 5−8 However, compositions with hexadecylamine (HDA3) and the highest oleate content (OL2.5) lead to more rounded nanoparticles (Figure 2).…”

Section: Resultsmentioning

confidence: 99%

CaSO₄ Mineralization in Carboxy- and Amino-Functionalized Reverse Micelles Unravels Shape-Dependent Transformations and Long-Term Stabilization Pathways for Poorly Hydrated Nanophases (Bassanite)

Tartaj

Morales

Fernández-Dı́az

2015

Crystal Growth & Design

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Mineralization studies on calcium sulfates when compared to those on phosphates and carbonates are relatively rare despite the economic relevance of these sulfates. A series of recent findings, however, have renewed the interest in calcium sulfate mineralization. These studies, similar to those on calcium carbonates and phosphates, have shown a richer than previously thought scenario especially at the nanoscale. Here, we intentionally use confinement reactors with fast exchange rates (organically/inorganically functionalized reverse micelles) to rapidly establish pathways relevant to calcium sulfate mineralization in solution (including long-term stabilization). Furthermore, we rationalize all the results on the basis of an adsorption model with solubility inputs for inorganic additives. Thus, the typical bassanite nanofibers involving oriented attachment are observed either at weak-adsorption conditions or in the presence of less soluble inorganic dopants. At strong adsorption conditions, nanofibers are no longer observed, and long-term stabilization of nanobassanites is chemically possible if calcium/carboxylate bridging bonds are established during the first stages of nucleation and growth (aliquots after 30 min are similar to 24 h and remain preserved after 5 months). The results here presented are thus important, as they suggest specific conditions for the stabilization of biogenic bassanites. Furthermore, our results suggest that when oriented attachment is no longer energetically favored at intermediate stages (presence of rounded nanoparticles instead of nanorods), gypsum crystallization still can occur from small nanobassanites, however, through a classical dissolution−recrystallization mechanism.

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Section: Resultsmentioning

confidence: 99%

CaSO₄ Mineralization in Carboxy- and Amino-Functionalized Reverse Micelles Unravels Shape-Dependent Transformations and Long-Term Stabilization Pathways for Poorly Hydrated Nanophases (Bassanite)

Tartaj

Morales

Fernández-Dı́az

2015

Crystal Growth & Design

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“…The instrument was equipped with a Göbel mirror (Schuster and Göbel 1995) and Soller slits on both incident and diffracted beams. This experimental set-up is very effective in reducing the occurrence of texture effects (Ballirano et al 2001;Ballirano 2003). Details of data collection are reported in Table 1.…”

Section: Experimental Methodsmentioning

confidence: 99%

Mineralogical characterization of the blue pigment of Michelangelo's fresco "The Last Judgment"

Ballirano

Maras

2006

American Mineralogist

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“…When the Na 2 EDTA reaches 10 mM, α-HH polycrystals grow into perfect spheres with smooth surfaces of 2 µm in diameter (Figure 4e). 24,28 Thus without Na 2 EDTA, α-HH whiskers are obtained, which consists with its crystallization habit. As an anisotropic crystal, α-HH shows distinct growth rates at different crystal planes.…”

Section: Effect Of Na 2 Edtamentioning

confidence: 99%

A facile method to control the structure and morphology of α-calcium sulfate hemihydrate

et al. 2015

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We report a facile method to control the structure and morphology of alpha-calcium sulfate hemihydrate (α-HH) crystals precipitated in Na 2 EDTA-contained ethylene glycol aqueous solutions by simply tuning the volume ratio of ethylene glycol to water (G/W). At a low G/W from 0.4 to 2.5, single crystalline α-HH particles with hexagonal prism shape precipitate from the solution, the corresponding aspect ratio of the prisms varies from 2.7 to 0.1. While at a high G/W from 5.0 to 50.0, polycrystalline α-HH particles form with spherical and ellipsoidal shape and the diameter of the polycrystalline spheres reduces from 2 µm to 300 nm. The synergetic effect of supersaturation and Na 2 EDTA activity resulted from G/W accounts for the evolution of structure and morphology of α-HH. This method allows α-HH synthesis in micro and nanoscale size, thus enabling its morphology/structure-dependent applications.

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The monoclinic I2 structure of bassanite, calcium sulphate hemihydrate (CaSO4 0.5H2O)

Cited by 81 publications

References 0 publications

CaSO₄ Mineralization in Carboxy- and Amino-Functionalized Reverse Micelles Unravels Shape-Dependent Transformations and Long-Term Stabilization Pathways for Poorly Hydrated Nanophases (Bassanite)

CaSO₄ Mineralization in Carboxy- and Amino-Functionalized Reverse Micelles Unravels Shape-Dependent Transformations and Long-Term Stabilization Pathways for Poorly Hydrated Nanophases (Bassanite)

Mineralogical characterization of the blue pigment of Michelangelo's fresco "The Last Judgment"

A facile method to control the structure and morphology of α-calcium sulfate hemihydrate

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The monoclinic I2 structure of bassanite, calcium sulphate hemihydrate (CaSO4 0.5H2O)

Cited by 81 publications

References 0 publications

CaSO4 Mineralization in Carboxy- and Amino-Functionalized Reverse Micelles Unravels Shape-Dependent Transformations and Long-Term Stabilization Pathways for Poorly Hydrated Nanophases (Bassanite)

CaSO4 Mineralization in Carboxy- and Amino-Functionalized Reverse Micelles Unravels Shape-Dependent Transformations and Long-Term Stabilization Pathways for Poorly Hydrated Nanophases (Bassanite)

Mineralogical characterization of the blue pigment of Michelangelo's fresco "The Last Judgment"

A facile method to control the structure and morphology of α-calcium sulfate hemihydrate

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CaSO₄ Mineralization in Carboxy- and Amino-Functionalized Reverse Micelles Unravels Shape-Dependent Transformations and Long-Term Stabilization Pathways for Poorly Hydrated Nanophases (Bassanite)

CaSO₄ Mineralization in Carboxy- and Amino-Functionalized Reverse Micelles Unravels Shape-Dependent Transformations and Long-Term Stabilization Pathways for Poorly Hydrated Nanophases (Bassanite)