Synthesis and Characterization of Spherical Calcium Carbonate Nanoparticles Derived from Cockle Shells

Abstract

Cockle shells are a natural reservoir of calcium carbonate (CaCO3), which is widely used in bone repair, tissue scaffolds, and the development of advanced drug delivery systems. Although many studies report on the preparation of CaCO3, the development of a nanosized spherical CaCO3 precursor for calcium oxide (CaO) that is suitable to be incorporated in dental material was scarce. Therefore, this study aimed to synthesize a nanosized spherical CaCO3 precursor for CaO derived from cockle shells using a sol–gel method. Cockle shells were crushed to powder form and mixed with hydrochloric acid, forming calcium chloride (CaCl2). Potassium carbonate (K2CO3) was then fed to the diluted CaCl2 to obtain CaCO3. The effect of experimental parameters on the morphology of CaCO3, such as volume of water, type of solvents, feeding rate of K2CO3, and drying method, were investigated using field-emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffractometry (XRD), Brunauer–Emmett–Teller surface area analysis, and thermogravimetric analysis. Optimized CaCO3 was then calcined to form CaO. XRD analysis of CaCO3 nanoparticles was indicative of the formation of a calcite phase. The well-structured spherical shape of CaCO3 was obtained by the optimum condition of the addition of 50 mL of water into CaCl2 in ethanolic solution with a 1 h feeding rate of K2CO3. Less agglomeration of CaCO3 was obtained using a freeze-drying technique with the surface area of 26 m2/g and average particle size of 39 nm. Spherical shaped nanosized CaO (22–70 nm) was also synthesized. The reproducibility, low cost, and simplicity of the method suggest its potential applications in the large-scale synthesis of the nanoparticles, with spherical morphology in an industrial setting.

Synthesis and Characterization of Gefitinib and Paclitaxel Mono and Dual Drug-Loaded Blood Cockle Shells (Anadara granosa)-Derived Aragonite CaCO3 Nanoparticles

“…Some of the popular method for synthesizing calcium carbonate nanoparticles viz. precipitation [ 43 ], sol-gel method [ 52 , 53 ], and layer by layer deposition [ 51 ]. As explained by the name, the top-down method is where larger particles (blood cockle shells) are broken down into smaller nanometer-sized particles.…”

“…Two studies by Yang et al [ 94 ] and Chong et al [ 95 ] revealed that there occurs a strong peak at 2θ of 29.4, indicative of calcite, and this peak disappeared when the calcium carbonate became aragonite. In a paper published by Hussein et al [ 53 ] where the cockle shells were used to synthesize nanoparticles using a sol-gel method, this resulted in a calcite phase, characterized by the peak of 2θ at 29.5, was the confirmatory sign of calcite. In the current study, we found no diffraction around that region in the diffractogram of the nanoparticles synthesized, which indicates that these nanoparticles are purely aragonite.…”

“…The crystallite size of the synthesized nanoparticles ranged from 30.1 nm to 32.8 nm. In a 2020 study, calcium carbonate nanoparticles of crystallite size of 61.4 nm were synthesized from cockle shells as the source of calcite calcium carbonate nanoparticles [ 53 ]. Another study by Lee et al [ 82 ] shows that calcite calcium carbonate nanoparticles were ~30 nm, which is in the same range as the crystallite size obtained in this study.…”

“… 1 Current study, 2 [ 33 ], 3 [ 37 ], 4 [ 53 ], 5 [ 82 ], 6 [ 112 ], * Aragonite, + Calcite, # Amorphous. CSCaCO 3 NP, Blood cockle shell derived CaCO 3 nanoparticles; GEF-CSCaCO 3 NP, GEF loaded Blood cockle shell derived CaCO 3 nanoparticles; PTXL-CSCaCO 3 NP, PTXL loaded Blood cockle shell derived CaCO 3 nanoparticles; GEF-PTXL-CSCaCO 3 NP, GEF and PTXL loaded Blood cockle shell derived CaCO 3 nanoparticles; DTX-CaCO 3 NP, Docetaxel loaded cockle shell derived CaCO 3 nanoparticles; N-Cal, Nano calcium carbonate; NA, not available.…”

The Application of Zirconia in Tooth Defects

“…As reported, Ce-TZP/A is currently the toughest zirconia material available, and its fracture toughness reaches 19 MPa m 1/2 , and the flexural strength is high as 1400 MPa [65]. More importantly, Ce-TZP/A is entirely resistant to low-temperature aging degradation (LTAD), a critical drawback of Y-TZP [67]. The tremendous improvement of these characteristics is expected to extend the clinical application of dental ceramics to all-ceramic restorations and other areas, such as implant abutments, implants, removable denture bases, and components.…”