Synthesis of Nano Calcium Carbonate from Natural CaO by CO_2 Fine Bubbling Method

摘要

Calcium carbonate (CaCO_3) is easily found in nature but has a large size so it is not effective as a filler in toothpaste. Nano calcium carbonate toothpaste can release calcium faster than non-nano calcium carbonate. The purpose of this study was to synthesize CaCO_3 from natural CaO into nano-sizes with varying concentrations of Ca(OH)_2 as operational parameters. CaO from Palimanan was hydrated to produce Ca(OH)_2 with different concentrations (0.01 M, 0.03 M, and 0.05 M) and subsequently Ca(OH)_2 was carbonized by the CO_2 fine bubbling method through fine bubble generator to form CaC03. The results of particle size using PSA showed that CaC03 produced with Ca(OH)_2 concentration of 0.01 Mhad a smaller size (650.7 nm) compared to the Ca(OH)_2 concentration of 0.03 Mand 0.05 M. Based on analysis of XRD, CaC03 obtained from the three Ca(OH)_2 concentrations have calcite structures. The decreasing particle size of CaC03 is caused by a decrease in solution supersaturation due to a decrease in the concentration of Ca(OH)_2. Decreasing Ca(OH)_2 concentration reduced the size of CaC03 nanoparticles. However crystallinity is higher with the concentration of Ca(OH)_2 0.03 M. Further investigation, to determine the morphology, composition, and functional groups of CaC03, characterization of SEM, XRF, FTIR is needed.