scholarly journals Impact of a Partial Solid Solution and Water Molecules on the Formation of Fibrous Crystals and Fluid Inclusions

Crystals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1188
Author(s):  
Laureline Marc ◽  
Chrystal Lopes ◽  
Jean-Marie Schneider ◽  
Morgane Sanselme ◽  
Gérard Coquerel
Keyword(s):  
Solid Solution ◽  
Fluid Inclusion ◽  
Single Crystals ◽  
Fluid Inclusions ◽  
Solid Phase ◽  
Large Bubble ◽  
Water Molecules ◽  
Pure Ethanol ◽  
High Fraction ◽  
Phase Water

Resolution of (±)ibuprofen using S-α-Methylbenzylamine in pure ethanol leads to the enriched S-IBU/S-αMBA diastereomeric salt which crystallizes as very fine needles. In order to improve the filterability and processability of the solid phase, water can be added to the medium and lead to more equant particles that are still elongated. A high fraction of the resulting platelets display on both ends a fluid inclusion containing both liquid and a large bubble of gas. A detailed analysis of the particles reveals that they are not really single crystals but more an ordered association of fibers defined as fibrous crystal. A domain of partial solid solution is evidenced near the pure less soluble diastereomer and its impact on the formation of fibrous crystals is demonstrated. When pure S-IBU/S-αMBA diastereomeric salt is recrystallized in the same medium (e.g., ethanol–water) the crystallinity is improved, but fluid inclusions can still be observed.

scholarly journals Prediction of Mississippi-Valley type ore fluid metal concentrations from solid solution metal concentrations in ore-stage minerals

2017 ◽  
Author(s):  
◽  
Sarah Smith
Keyword(s):  
Solid Solution ◽  
Fluid Inclusion ◽  
Distribution Coefficient ◽  
Fluid Inclusions ◽  
Mississippi Valley ◽  
Carbonate Minerals ◽  
Metal Concentrations ◽  
Fluid Inclusion Data ◽  
Mvt Deposits ◽  
Mississippi Valley Type

Mississippi-Valley-type (MVT) deposits have some of the greatest enrichments of Pb, Zn, Ba, and F in the Earth's crust. Fundamental to understanding how these elements were transported and precipitated to form MVT deposits is knowledge of their concentrations in the ore fluids. Recent research aimed at determining the concentrations of Pb, Zn, and Ba in the ore fluids that formed the MVT deposits of the U.S. midcontinent, the type examples for the MVT deposit class, has focused on using LA-ICPMS to analyze fluid inclusions. This research has shown U.S. mid-continent MVT ore fluids to have Ba concentrations on the order of 10's of ppm. However, LA-ICP-MS results for Pb and Zn concentrations are equivocal due to interferences from Zn and Pb in the host mineral matrix and uncertainties about whether the measured Pb and Zn signals represent aqueous solute or "accidentals", i.e. Pb or Zn solid particulates entrained within the fluid inclusions. In light of these limitations, this study sought to determine metal concentrations in MVT ore fluids instead by calculating them theoretically based on their solid solution concentrations in the ore-stage minerals calcite and galena. Using experimental partition coefficients from Rimstidt et al. (1998) at ore stage temperatures and measured compositions of ore-stage calcite from the Illinois-Kentucky and Central Tennessee MVT districts, concentrations of Mg, Mn, Fe, Zn, Sr, Ba, and Pb in the ore fluid were predicted. The predicted ore fluid concentrations of Mg and Mn, which form carbonate minerals (magnesite and rhodochrosite) with the calcite structure, were in good agreement with available fluid inclusion data for these elements. Thus, the predicted ore fluid concentrations of Zn and Fe, which also form carbonate minerals (smithsonite and siderite) with the calcite structure, 10s of ppm Zn and 1s to 10s of ppm Fe in Illinois-Kentucky and a maximum of 10s of ppm Zn and 1s to 10s of ppm Fe in Central Tennessee , are likely to be accurate. These Zn concentrations are typical of modern sedimentary brines and high enough to allow efficient Zn ore formation. In contrast, the predicted ore fluid concentrations of Sr and Ba, which form carbonate minerals (strontianite and witherite) with the aragonite structure, were in poor agreement with available fluid inclusion data for these elements. Thus, the predicted 1s of ppm ore fluid concentration of Pb, which also forms a carbonate mineral (cerussite) with the aragonite structure, is unlikely to be accurate. Using predicted thermodynamic data (Sverjensky, 1985) for ZnS with the galena structure, a thermodynamic distribution coefficient for Zn between aqueous solution and solid solution in galena was calculated. This distribution coefficient was used in combination with Zn concentrations measured in solid solution in galena from the Central Missouri, Central Tennessee, Illinois-Kentucky, Northern Arkansas, Tri-State, and Southeast Missouri MVT districts to predict Zn/Pb ratios for the ore fluids. The Zn/Pb ratios do not agree with the ore Zn/Pb ratios of the districts and appear to be an artifact of the temperature used in the calculations. Therefore the predicted ore fluid Zn/Pb ratios are unlikely to be correct.

scholarly journals Solid-Phase “Self-Hydrolysis” of [Zn(NH3)4MoO4@2H2O] Involving Enclathrated Water—An Easy Route to a Layered Basic Ammonium Zinc Molybdate Coordination Polymer

Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 4022
Author(s):  
Kende Attila Béres ◽  
István E. Sajó ◽  
György Lendvay ◽  
László Trif ◽  
Vladimir M. Petruševski ◽  
...  
Keyword(s):  
Coordination Polymer ◽  
Solid Phase ◽  
Water Molecules ◽  
Temperature Dependent ◽  
Dynamic Interactions ◽  
Ammonia Release ◽  
Successive Substitution ◽  
Red Dye ◽  
Hydrolysis Of ◽  
Zinc Molybdate

An aerial humidity-induced solid-phase hydrolytic transformation of the [Zn(NH3)4]MoO4@2H2O (compound 1@2H2O) with the formation of [(NH4)xH(1−x)Zn(OH)(MoO4)]n (x = 0.92–0.94) coordination polymer (formally NH4Zn(OH)MoO4, compound 2) is described. Based on the isostructural relationship, the powder XRD indicates that the crystal lattice of compound 1@2H2O contains a hydrogen-bonded network of tetraamminezinc (2+) and molybdate (2−) ions, and there are cavities (O4N4(μ-H12) cube) occupied by the two water molecules, which stabilize the crystal structure. Several observations indicate that the water molecules have no fixed positions in the lattice voids; instead, the cavity provides a neighborhood similar to those in clathrates. The @ symbol in the notation is intended to emphasize that the H2O in this compound is enclathrated rather than being water of crystallization. Yet, signs of temperature-dependent dynamic interactions with the wall of the cages can be detected, and 1@2H2O easily releases its water content even on standing and yields compound 2. Surprisingly, hydrolysis products of 1 were observed even in the absence of aerial humidity, which suggests a unique solid-phase quasi-intramolecular hydrolysis. A mechanism involving successive substitution of the ammonia ligands by water molecules and ammonia release is proposed. An ESR study of the Cu-doped compound 2 (2#dotCu) showed that this complex consists of two different Cu2+(Zn2+) environments in the polymeric structure. Thermal decomposition of compounds 1 and 2 results in ZnMoO4 with similar specific surface area and morphology. The ZnMoO4 samples prepared from compounds 1 and 2 and compound 2 in itself are active photocatalysts in the degradation of Congo Red dye. IR, Raman, and UV studies on compounds 1@2H2O and 2 are discussed in detail.

scholarly journals Removal of Chromium from Aqueous Solution Using Modified Pomegranate Peel:Mechanistic and Thermodynamic Studies

2009 ◽  
Vol 6 (s1) ◽  
pp. S153-S158 ◽  
Author(s):  
Tariq S. Najim ◽  
Suhad A. Yassin
Keyword(s):  
Activation Energy ◽  
Solid Solution ◽  
Aqueous Solution ◽  
Adsorption Process ◽  
Batch Process ◽  
The Other ◽  
Water Molecules ◽  
Pomegranate Peel ◽  
Solution Interface ◽  
Adsorbent Surface

Modified pomegranate peel (MPGP) and formaldehyde modified pomegranate peel (FMPGP) were prepared and used as adsorbent for removal of Cr(VI) ions from aqueous solution using batch process. The temperature variation study of adsorption on both adsorbents revealed that the adsorption process is endothermic, from the positive values of ∆H˚. These values lie in the range of physisorption. The negative values of ∆G˚ show the adsorption is favorable and spontaneous. On the other hand, these negative values increases with increase in temperature on both adsorbents, which indicate that the adsorption is preferable at higher temperatures. ∆S˚ values showed that the process is accompanied by increase in disorder and randomness at the solid solution interface due to the reorientation of water molecules and Cr(VI) ions around the adsorbent surface. The endothermic nature of the adsorption was also confirmed from the positive values of activation energy, Ea, the low values of Ea confirm the physisorption mechanism of adsorption. The sticking probability, S*, of Cr(VI) ion on surface of both adsorbents showed that the adsorption is preferable due to low values of S*(0< S*< 1 ), but S*values are lower for FMPGP indicating that the adsorption on FMPGP is more preferable .

scholarly journals Low-temperature Synthesis of Nanometer-sized Single Crystals in MgO-ZnO Solid Solution

2002 ◽  
Vol 75 (7) ◽  
pp. 327-329 ◽  
Author(s):  
Seisaku OHSHIRO ◽  
Mitsunobu IWASAKI ◽  
Masayoshi HARA ◽  
Seishiro ITO
Keyword(s):  
Solid Solution ◽  
Low Temperature ◽  
Single Crystals ◽  
Low Temperature Synthesis ◽  
Temperature Synthesis

Growth and structural investigations of La1−xPrxGaO3 solid solution single crystals

2001 ◽  
Vol 222 (1-2) ◽  
pp. 194-201 ◽  
Author(s):  
M. Berkowski ◽  
J. Fink-Finowicki ◽  
P. Byszewski ◽  
R. Diduszko ◽  
E. Kowalska ◽  
...  
Keyword(s):  
Solid Solution ◽  
Single Crystals ◽  
Structural Investigations

Formation of emeralds at pegmatite-ultramafic contacts based on fluid inclusions in Kianjavato emerald, Mananjary deposits, Madagascar

2006 ◽  
Vol 70 (2) ◽  
pp. 141-158 ◽  
Author(s):  
Ye. Vapnik ◽  
I. Moroz ◽  
M. Roth ◽  
I. Eliezri
Keyword(s):  
Fluid Inclusion ◽  
Fluid Inclusions ◽  
East Coast ◽  
Fluid Inclusion Data ◽  
Pan African ◽  
Probe Analysis ◽  
Raman Probe

AbstractKianjavato emerald (Mananjary deposits, East coast of Madagascar) was formed during metasomatic processes at the contact between pegmatites and hornblendites. The metasomatic exchange was related to a Pan-African tectonometamorphic event.Fluid inclusions in the Kianjavato emerald and quartz were studied by means of microthermometry and Raman probe analysis. Three main types of inclusions were revealed: CO2-rich, CH4-rich and aqueous-rich, with a salinity of ∼2 wt.% NaCl equiv. The inclusions occurred along the same primary and pseudosecondary trails and were considered to be formed simultaneously. Based on fluid-inclusion data, the conditions of emerald growth were 250°C < T < 450°C and P = 1.5 kbar.The fluid inclusion data for Kianjavato emerald were compared to the data for another Madagascar emerald, Ianapera. The latter is of similar age, but its genesis was determined by a shearing event. Our fluid inclusion data suggested that shearing was also important as a mechanism of introducing CO2-rich fluid for the genesis of the Kianjavato emerald.

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