Synthesis and characterization of CaCO3 (calcite) nano particles from cockle shells (Anadara granosa Linn) by precipitation method

Abstract

Calcium supplements can reduce the risk of osteoporosis, but they are not automatically absorbed in the gastrointestinal tract. Nanotechnology is presumed to have a capacity in resolving this problem. The preparation and characterization of calcium carbonate nano particle to improve the solubility was performed. Calcium carbonate nano particles were synthesized using precipitation method from cockle shells (Anadara granosa Linn). Samples of the cockle shells were dried in an oven at temperature of 50°C for 7 (seven) days and subsequently they were crushed and blended into fine powder that was sieved through 125-μm sieve. The synthesis of calcium carbonate nanocrystals was done by extracting using hydro chloride acid and various concentrations of sodium hydroxide were used to precipitate the calcium carbonate nano particles. The size of the nano particles was determined by SEM, XRD data, and Fourier transform infrared spectroscopy (FT-IR). The results of XRD indicated that the overall crystalline structure and phase purity of the typical calcite phase CaCO3 particles were approximately 300 nm in size. The method to find potential applications in industry to yield the large scale synthesis of aragonite nano particles by a low cost but abundant natural resource such as cockle shells is required.