Hydrotalcite type clays such as fluoride nanocarriers: synthesis, characterization and kinetic evaluation

The objective of this study was to develop a hydrotalcite-type nano-structured fluoridated layered double hydroxide (LDH) release system for controlled delivery of fluoride ions. The synthesis of precursor nanomaterials of the conventional LDH-type was carried out through the co-precipitation method at constant pH; and nanoparticulate-LDH was synthetized by hydrothermal procedure. Fluoride products were obtained through the indirect synthesis by the ion exchange technique from the precursors, varying time of agitation and temperature. The materials were characterized by EDX, DRX, FTIR, TGA and MEV. The kinetic profile of F-release was evaluated during 21 days in neutral and acid medium. The varied synthesis conditions provided differentiated products in terms of fluoride quantification, revealing specific release profiles and there was a higher F-release in pH 5,5. There was success in obtaining the fluoride-LDH as well as a controlled delivery of fluoride ions which promising as a new nanomaterial to be used in formulations.