title: Role of CaCO3° Neutral Pair in Calcium Carbonate Crystallization.
abstract: The molecular structure of the units that get incorporated into the nuclei of the crystalline phase and sustain their growth is a fundamental issue in the pathway from a supersaturated solution to the formation of crystals. Using a fluorescent dye we have recorded the variation of the pH value in time along a gel where CaCl2and NaHCO3counter-diffuse to crystallize CaCO3. The same pH-space-time distribution maps were also computationally obtained using a chemical speciation code (phreeqc). Using data arising from this model we investigated the space-time evolution of the activity of the single species (ions and ion pairs) involved in the crystallization process. Our combined results suggest that, whatever the pathway from solution to crystals, the neutral pair CaCO3° is a key species in the CaCO3precipitation system.
authors: Dipartimento di Chimica "G. Ciamician", Alma Mater Studiorum Università di Bologna , via Selmi 2, I-40126 Bologna, Italy.
authors: Damiano
authors: D
authors: Genovese
authors: Dipartimento di Chimica "G. Ciamician", Alma Mater Studiorum Università di Bologna , via Selmi 2, I-40126 Bologna, Italy.
authors: Marco
authors: M
authors: Montalti
authors: Laboratorio de Estudios Cristalográficos, Instituto Andaluz de Ciencias de la Tierra (CSIC-UGR) , Avda. Las Palmeras, no 4, 18100 Armilla (Granada), Spain.
authors: Fermín
authors: F
authors: Otálora
authors: Laboratorio de Estudios Cristalográficos, Instituto Andaluz de Ciencias de la Tierra (CSIC-UGR) , Avda. Las Palmeras, no 4, 18100 Armilla (Granada), Spain.
authors: Jaime
authors: J
authors: Gómez-Morales
authors: Laboratorio de Estudios Cristalográficos, Instituto Andaluz de Ciencias de la Tierra (CSIC-UGR) , Avda. Las Palmeras, no 4, 18100 Armilla (Granada), Spain.
authors: María
authors: M
authors: Sancho-Tomás
authors: Dipartimento di Chimica "G. Ciamician", Alma Mater Studiorum Università di Bologna , via Selmi 2, I-40126 Bologna, Italy.
authors: Giuseppe
authors: G
authors: Falini
authors: Laboratorio de Estudios Cristalográficos, Instituto Andaluz de Ciencias de la Tierra (CSIC-UGR) , Avda. Las Palmeras, no 4, 18100 Armilla (Granada), Spain.
authors: Juan Manuel
authors: JM
authors: García-Ruiz