Monodisperse Calcium Carbonate Microtablets Forming at 70°C in Prerefrigerated CaCl₂–Gelatin–Urea Solutions

Abstract

Calcium carbonate particles with a unique tablet shape were produced by simply aging the prerefrigerated (at 41C for 24 h) CaCl 2 -gelatin-urea solutions at 701C for 24 h in ordinary glass media bottles. Gelatin is known to be the denatured collagen. The thermal decomposition of dissolved urea was exploited to provide the Ca 21 ion and gelatin-containing solutions with aqueous carbonate ions. Monodisperse CaCO 3 microtablets formed in solution had a mean particle size of 472.5 mm. CaCO 3 microtablets were biphasic in nature and comprised of about 93% vaterite and 7% calcite. Identical solutions used without prerefrigeration yielded only trigonal prismatic calcite crystals upon aging at 701C for 24 h. Prerefrigeration of CaCl 2 -gelatin-urea solutions was thus shown to have a remarkable effect on the particle morphology. Samples were characterized by scanning electron microscopy, Fourier-transform infrared spectroscopy, and powder X-ray diffraction.

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

“…The main advantages of such particles' morphology are the porous structure, large surface area, and greater hydrophilicity in comparison to more stable calcite or aragonite [10,19,20]. Other morphological forms of vaterite can be also obtained, i.e., plates [21], hexagonal crystals [22], lenses [23], lamellar aggregates [24], florets, or rosettes [21,25] as well as microtablets [26]. Examples of vaterite particles are shown in Figure 2.…”

Synthetic Aragonite (CaCO3) as a Potential Additive in Calcium Phosphate Cements: Evaluation in Tris‐FreeSBFat 37°C

“…The metastable phase of vaterite can initially form in such aqueous solutions (HCO 3 − ‐to‐Ca 2+ ratio of 1.1) but they are not stable against calcite crystallization at RT during the course of 90 min of synthesis . The synthesis of monodisperse spheres and biconvex micropills of vaterite was previously described.…”

Facile synthesis of an optical sensor for CO32−and HCO3−detection

“…Carbonates of calcium are important materials for marine and geological processes, often created as a result of biomineralisation that is used by nature to perform many diverse functions in marine organisms including skeleton and shell growth. Carbonate compounds are used extensively in the manufacturing of glass, rayon, rubber, plastic, paper, printing ink, cosmetics, toothpaste and food; meanwhile, carbonates are important candidates for electric vehicle and hybrid electric vehicle power sources where vinylene carbonate are used as additive electrolytes for rechargeable Li-ion batteries [14][15][16][17][18]. Effluents produced from these industries often contain substantial concentration of carbonates.…”