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Solubility investigations in the amorphous calcium magnesium carbonate system
Amorphous precursors are known to occur in the early stages of carbonate mineral formation in both biotic and abiotic environments. Although the Mg content of amorphous calcium magnesium carbonate (ACMC) is a crucial factor for its temporal stabilization, to date little is known about its control on...
Autores principales: | , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Royal Society of Chemistry
2019
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6336086/ https://www.ncbi.nlm.nih.gov/pubmed/30760969 http://dx.doi.org/10.1039/c8ce01596a |
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author | Purgstaller, Bettina Goetschl, Katja E. Mavromatis, Vasileios Dietzel, Martin |
author_facet | Purgstaller, Bettina Goetschl, Katja E. Mavromatis, Vasileios Dietzel, Martin |
author_sort | Purgstaller, Bettina |
collection | PubMed |
description | Amorphous precursors are known to occur in the early stages of carbonate mineral formation in both biotic and abiotic environments. Although the Mg content of amorphous calcium magnesium carbonate (ACMC) is a crucial factor for its temporal stabilization, to date little is known about its control on ACMC solubility. Therefore, amorphous Ca(x)Mg(1–x)CO(3)·nH(2)O solids with 0 ≤ x ≤ 1 and 0.4 ≤ n ≤ 0.8 were synthesized and dispersed in MgCl(2)–NaHCO(3) buffered solutions at 24.5 ± 0.5 °C. The chemical evolution of the solution and the precipitate clearly shows an instantaneous exchange of ions between ACMC and aqueous solution. The obtained ion activity product for ACMC (IAP(ACMC) = “solubility product”) increases as a function of its Mg content ([Mg](ACMC) = (1 – x) × 100 in mol%) according to the expression: log(IAP(ACMC)) = 0.0174 (±0.0013) × [Mg](ACMC) – 6.278 (±0.046) (R(2) = 0.98), where the log(IAP(ACMC)) shift from Ca (–6.28 ± 0.05) to Mg (–4.54 ± 0.16) ACMC endmember, can be explained by the increasing water content and changes in short-range order, as Ca is substituted by Mg in the ACMC structure. The results of this study shed light on the factors controlling ACMC solubility and its temporal stability in aqueous solutions. |
format | Online Article Text |
id | pubmed-6336086 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2019 |
publisher | Royal Society of Chemistry |
record_format | MEDLINE/PubMed |
spelling | pubmed-63360862019-02-11 Solubility investigations in the amorphous calcium magnesium carbonate system Purgstaller, Bettina Goetschl, Katja E. Mavromatis, Vasileios Dietzel, Martin CrystEngComm Chemistry Amorphous precursors are known to occur in the early stages of carbonate mineral formation in both biotic and abiotic environments. Although the Mg content of amorphous calcium magnesium carbonate (ACMC) is a crucial factor for its temporal stabilization, to date little is known about its control on ACMC solubility. Therefore, amorphous Ca(x)Mg(1–x)CO(3)·nH(2)O solids with 0 ≤ x ≤ 1 and 0.4 ≤ n ≤ 0.8 were synthesized and dispersed in MgCl(2)–NaHCO(3) buffered solutions at 24.5 ± 0.5 °C. The chemical evolution of the solution and the precipitate clearly shows an instantaneous exchange of ions between ACMC and aqueous solution. The obtained ion activity product for ACMC (IAP(ACMC) = “solubility product”) increases as a function of its Mg content ([Mg](ACMC) = (1 – x) × 100 in mol%) according to the expression: log(IAP(ACMC)) = 0.0174 (±0.0013) × [Mg](ACMC) – 6.278 (±0.046) (R(2) = 0.98), where the log(IAP(ACMC)) shift from Ca (–6.28 ± 0.05) to Mg (–4.54 ± 0.16) ACMC endmember, can be explained by the increasing water content and changes in short-range order, as Ca is substituted by Mg in the ACMC structure. The results of this study shed light on the factors controlling ACMC solubility and its temporal stability in aqueous solutions. Royal Society of Chemistry 2019-01-07 2018-11-20 /pmc/articles/PMC6336086/ /pubmed/30760969 http://dx.doi.org/10.1039/c8ce01596a Text en This journal is © The Royal Society of Chemistry 2019 http://creativecommons.org/licenses/by-nc/3.0/ This article is freely available. This article is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported Licence (CC BY-NC 3.0) |
spellingShingle | Chemistry Purgstaller, Bettina Goetschl, Katja E. Mavromatis, Vasileios Dietzel, Martin Solubility investigations in the amorphous calcium magnesium carbonate system |
title | Solubility investigations in the amorphous calcium magnesium carbonate system
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title_full | Solubility investigations in the amorphous calcium magnesium carbonate system
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title_fullStr | Solubility investigations in the amorphous calcium magnesium carbonate system
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title_full_unstemmed | Solubility investigations in the amorphous calcium magnesium carbonate system
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title_short | Solubility investigations in the amorphous calcium magnesium carbonate system
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title_sort | solubility investigations in the amorphous calcium magnesium carbonate system |
topic | Chemistry |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6336086/ https://www.ncbi.nlm.nih.gov/pubmed/30760969 http://dx.doi.org/10.1039/c8ce01596a |
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