Seminarium "Teoria i Modelowanie Nanostruktur"

There are numerous studies of its properties on calcium carbonate precipitation,however the exact path of CaCO3 nucleation is still unknown. In my research I focus on thespontaneous CaCO3 precipitation from aqueous solutions, which can be triggered by acombination of factors including supersaturation and the presence of foreign particulatematter, which may act as a nucleation point. Calcium carbonate may nucleate either due tothe so-called classical nucleation path or the alternative one. The general idea of the classicalnucleation is based on the reversible process of adding ions to the pre-critical cluster, whichcan happen in a supersaturation solution. The post critical nuclei obtained grow to the finalcrystals of CaCO3 (ion-by-ion attachment). Non-classical path involves the preliminaryaggregation of the prenucleation clusters into amorphous CaCO3 nanoparticles (ACC).The sign and the magnitude of the ζ potential indicates on stability of colloidaldispersions. The amorphous phase of calcium carbonate can be stabilized by use ofmagnesium ions. The presence of Mg2+ influences transformation between amorphouscalcium carbonate phase and CaCO3 polymorphs.Experiments were performed using facile precipitation of CaCO3 by mixing aqueoussolutions of CaCl2 with Na2CO3 in distilled water and adding MgCl2 to control calciumcarbonate precipitation by various additions.