Synthesis Methods and Favorable Conditions for Spherical Vaterite Precipitation: A Review

Abstract

Vaterite is the least thermodynamically stable anhydrous calcium carbonate polymorph. Its existence is very rare in nature, e.g., in some rock formations or as a component of biominerals produced by some fishes, crustaceans, or birds. Synthetic vaterite particles are proposed as carriers of active substances in medicines, additives in cosmetic preparations as well as adsorbents. Also, their utilization as a pump for microfluidic flow is also tested. In particular, vaterite particles produced as polycrystalline spheres have large potential for application. Various methods are proposed to precipitate vaterite particles, including the conventional solution-solution synthesis, gas-liquid method as well as special routes. Precipitation conditions should be carefully selected to obtain a high concentration of vaterite in all these methods. In this review, classical and new methods used for vaterite precipitation are presented. Furthermore, the key parameters affecting the formation of spherical vaterite are discussed.

Surfactin as a Green Agent Controlling the Growth of Porous Calcite Microstructures

“…The addition of surfactin at concentrations of 10 and 20 ppm increased the negative value of the zeta potential to −30 and −36.1 mV, respectively, at a pH of approximately 10 ± 0.3. The changes in zeta potential value were also observed by other researchers using polypeptides, fulvic acid or stearic acid [ 18 , 19 ]. From previous data in the literature, it is known that biomolecules can adsorb on solid faces formed as a result of the crystallization process and change the interfacial energy [ 20 , 21 ].…”

“…Surfactin molecules can adsorb on the vaterite surface via electrostatic interactions as well as via hydrogen bonds between protonated amino groups and oxygen in the carbonate group on the crystal surface [ 47 , 48 ]. The presence of surfactin molecules on the solid/liquid interface changed the solubility of vaterite [ 18 ]. As a result, further conversion of crystals into calcite slowed down ( Table 5 ), followed by gradual changes in morphology ( Figure 6 ), crystallite size ( Figure 7 C) and microstrain ( Figure 7 D).…”

The Effect of Hydrothermal Holding Time on The Characterization of Hydroxyapatite Synthesized from Green Mussel Shells

“…In addition, at a low CO2 gas flow rate it will reduce the supersaturation of the solution due to the lack of availability of CO2 gas so that the supersaturation of the solution is low. At low supersaturation that causes aragonite particles to form [18][19][20][21][22][23][24][25].…”

Encapsulation of Low-Molecular-Weight Drugs into Polymer Multilayer Capsules Templated on Vaterite CaCO3 Crystals

“…The aforementioned vaterite CaCO 3 crystals are widely used as sacrificial cores for the fabrication of PEMCs [ 37 , 38 , 39 ] as well as larger tailor-made polymer based structures like porous polymer scaffolds [ 40 , 41 , 42 , 43 ]. The vaterite polymorph belongs to a family of naturally derived minerals [ 44 ], but can be readily produced from low-cost precursor salts (e.g., sodium carbonate and calcium chloride) at either the micro- or nanoscale [ 45 , 46 ]. Moreover, they are eco-friendly and highly biocompatible, and may be readily decomposed under mild conditions (e.g., at slightly acidic pH below 7 or in the presence of chelating agents such as ethylenediaminetetraacetic acid (EDTA) or citric acid).…”