Amorphous Calcium Carbonate Constructed from Nanoparticle Aggregates with Unprecedented Surface Area and Mesoporosity

• DOI: 10.1021/acsami.8b03939
• Publication Date: 2018-06-04T14:28:23Z
• Authors: Rui Sun; Peng Zhang; Éva G. Bajnóczi; Alexandra Neagu; Cheuk-Wai Tai; Ingmar Persson; Maria Strømme; Ocean Cheung
• Keywords: Specific surface area; Amorphous calcium phosphate; Amorphous calcium carbonate

Amorphous calcium carbonate (ACC), with the highest reported specific surface area of all current forms (over 350 m2 g–1), was synthesized using a surfactant-free, one-pot method. Electron microscopy, helium pycnometry, and nitrogen sorption analysis revealed that this highly mesoporous ACC, pore volume ∼0.86 cm3 g–1 pore-size distribution centered at 8–9 nm, is constructed from aggregated ACC nanoparticles an estimated average diameter 7.3 nm. The porous remained amorphous retained its high porosity for over 3 weeks under semi-air-tight storage conditions. Powder X-ray diffraction, large-angle scattering, infrared spectroscopy, electron diffraction exposed did not resemble any known CaCO3 structures. atomic order diminished interatomic distances 8 Å. Porous evaluated as potential drug carrier poorly soluble substances in vitro. Itraconazole celecoxib stable their within pores material. Drug release rates were significantly enhanced both drugs (up to 65 times dissolution crystalline forms), supersaturation also demonstrated. Citric acid used enhance stability aggregates, which increased material 600 g–1. This has use various applications where important, including adsorption, catalysis, medication, bone regeneration.