Loading...
Please wait, while we are loading the content...
Similar Documents
Effect of pH and Type of Stirring on the Spontaneous Precipitation of $CaCO_{3}$ at Identical Initial Supersaturation, Ionic Strength and a(Ca^{2+})/a(CO_{3}$^{2−}$) Ratio
| Content Provider | MDPI |
|---|---|
| Author | Nenad, Tomašić Nives, Matijaković Mlinarić Branka, Njegić Džakula Kontrec, Jasminka Kralj, Damir |
| Copyright Year | 2021 |
| Description | $CaCO_{3}$ precipitation is physical-chemical basis of biomineral formation of hard tissue (shells, skeletons) in marine calcifying organisms (=biomineralization). Processes controlling biomineralization are still not fully clarified, so the study of influence of pH on basic processes of $CaCO_{3}$ precipitation should contribute to better understanding of biomineralization under climate change. This paper reports on the effect of initial pH $(pH_{0}$) and type of stirring (mechanical and magnetical) on spontaneous precipitation and phase composition, size and morphology of spontaneously precipitated $CaCO_{3}$ formed at the identical initial supersaturation, ionic strength and a(Ca^{2+})/a(CO_{3}$^{2−}$) ratio. The initial pH varied in a range 8.50 ≤ $pH_{0}$ ≤ 10.50 and included values relevant for mimicking the conditions related to biomineralization in marine organisms. In all systems two $CaCO_{3}$ polymorphs were found: calcite and/or vaterite. The increase of $pH_{0}$ favoured the formation of rhombohedral calcite no matter the type of stirring. This was exclusively influenced by the systems’ $pH_{0}$ (other relevant initial parameters were identical). Furthermore, increase of $pH_{0}$ caused change of vaterite morphology from cauliflower-like spheroids to regular spherulites. The mechanically stirred systems produced larger calcite and vaterite particles and higher content of calcite. |
| Starting Page | 1075 |
| e-ISSN | 20734352 |
| DOI | 10.3390/cryst11091075 |
| Journal | Crystals |
| Issue Number | 9 |
| Volume Number | 11 |
| Language | English |
| Publisher | MDPI |
| Publisher Date | 2021-09-05 |
| Access Restriction | Open |
| Subject Keyword | Crystals Calcium Carbonate Biomineralization Spontaneous Precipitation Stirring Calcite Vaterite |
| Content Type | Text |
| Resource Type | Article |
