Precipitation and Transformation of Vaterite Calcium Carbonate in the Presence of Some Organic Solvents

Abstract

In this paper, the production of CaCO3 particles via the carbonation route in the reaction of CaCl2 and CO2, using NH3 as a promoter of CO2 absorption, was studied. The solvents used as the reaction media for CaCO3 precipitation were aqueous solutions of methanol, isopropanol and dimethyl sulfoxide (DMSO), in a concentration range of 0–20% (v/v). It was found that the presence of an organic additive influenced the precipitation rate, the content of vaterite in the obtained product, the morphology and the size of the precipitated CaCO3 particles, as well as the rate of its transformation into calcite. The presence of all added organic solvents reduced the vaterite concentration in the produced CaCO3 both at the end of the reaction and after incubation in the reaction medium for 1 h. However, the transformation of vaterite particles into calcite in the tested solutions was slower when the 4 h and 24 h procedures were compared. The interactions of solvents with calcite and vaterite were compared using HPLC tests. DMSO molecules interacted with vaterite particles the most strongly, while the interaction of isopropanol with this polymorph was the weakest. The opposite effect was observed for interactions with calcite particles, and the affinity decreased in the series: isopropanol, methanol, DMSO.

Influence of Silica Functionalization on Water Sorption and Thermochemical Heat Storage of Mesoporous SBA-15/CaCl2 Composites

“…This suggests that during the post functionalization using HMDS and toluene at 80 °C, some CaCl 2 phases already present in the SBA-15 might have transformed to CaCO 3 via a carbonation route. 40 XRD of COO − functionalized SCa4 exhibited both CaCl 2 •2H 2 O and CaCl 2 •4H 2 O phases suggesting the presence of large crystalline CaCl 2 particles in this composite that are outside the silica mesopores (Figure 1b).…”

“…CaCl 2 phases already present in the SBA-15 might have transformed to CaCO 3 via carbonation route 40. XRD of COOfunctionalized SCa4 exhibited both CaCl 2 .2H 2 O and CaCl 2 .4H 2 O phases…”

Transformation of Calcium Carbonate Polymorph From Various Type of Shells by Carbonation Methods

“…It was reported that the change in polymorph from calcite to vaterite and aragonite formation occurred at 40 ℃. The different report stated by Song et al, (2020) that the vaterite phase changes to calcite with an increase in temperature from 20 to 80 ° C. The vaterite formation observed at 60 ℃ (Konopacka-Łyskawa et al, 2020). Polymorph aragonite is the dominant species at high temperatures (Ramakrishna et al, 2017) due to higher growth rates of aragonite as compared to the other polymorphs (Chong et al, 2014).…”

“…CaCO3 was difficult in controlling its polymorphic character (Chong et al, 2014). Several factors affect the precipitation process and polymorph characteristics such as pH (Thriveni et al, 2016;Tobler et al, 2016), supersaturation (Ding et al, 2018), temperature (Chong et al, 2014), calcium source (Bang et al, 2015), precipitation method (Thriveni et al, 2016), mixing intensity (Ševčík, et al, 2015) and co-solvent type (Konopacka-Łyskawa et al, 2020). Organic additives affected the rate of precipitation and the morphology of the precipitated particles (Polat, 2020;Liu et al, 2012).…”

Dextran and Its Derivatives: Biopolymer Additives for the Modulation of Vaterite CaCO3 Crystal Morphology and Adhesion to Cells

“…[21,[26][27][28][29] One of the main drawbacks of vaterite crystals are their inherent metastability and rather quick degradation/recrystallization in aqueous environments. [30] Degradation/decomposition of vaterite is required for hard templating of polymer, protein, inorganic or hybrid structures [22,[31][32][33][34] by means of loading the vaterite pores, followed by vaterite solubilisation. Although such properties may be beneficial for some medical applications, for example, pH-triggered release in tumor sites, [35][36][37] many other applications require the stabilization of vaterite and the suppression of its recrystallization.…”