Powder Technology, Vol.370, 29-38, 2020
Study on preparation and crystalline transformation of nano- and micro-CaCO3 by supercritical carbon dioxide
Calcium carbonate (CaCO3) microparticles with controlled size and morphology were prepared by carbonization method in a closed reactor under high pressure and supercritical conditions. The saturated calcium hydroxide solution (Ca(OH)(2)) and CO2 were used as the reactants, and ethanolamine was used as the chemical additive. The optimal reaction conditions including the concentration of ethanolamine, temperature, time and pressure were investigated. The morphology and polymorphism of CaCO3 microparticles were characterized Fourier Transform Infrared Spectroscopy (FT-IR), X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM). The cubic and rod-like of pure calcite and porous microspheres of pure vaterite were prepared. The porous microspheres were investigated as carriers for drugs. We selected nitrendipine and lutein as model drugs, and the drug loading reached 0.335 g/g(CaCO3) and 0.121 g/g(CaCO3), respectively. (C) 2020 Elsevier B.V. All rights reserved.