title: Growth and Dissolution of Calcite in the Presence of Adsorbed Stearic Acid.
abstract: The interaction of organic molecules with the surface of calcite plays a central role in many geochemical, petrochemical, and industrial processes and in biomineralization. Adsorbed organics, typically fatty acids, can interfere with the evolution of calcite when immersed in aqueous solutions. Here we use atomic force microscopy in liquid to explore in real-time the evolution of the (1014) surface of calcite covered with various densities of stearic acid and exposed to different saline solutions. Our results show that the stearic acid molecules tend to act as "pinning points" on the calcite's surface and slow down the crystal's restructuring kinetics. Depending on the amount of material adsorbed, the organic molecules can form monolayers or bilayer islands that become embedded into the growing crystal. The growth process can also displaces the organic molecules and actively concentrate them into stacked multilayers. Our results provide molecular-level insights into the interplay between the adsorbed fatty acid molecules and the evolving calcite crystal, highlighting mechanisms that could have important implications for several biochemical and geochemical processes and for the oil industry.
authors.forename: Maria
authors.initials: M
authors.lastname: Ricci
authors.forename: Juan José
authors.initials: JJ
authors.lastname: Segura
authors.forename: Blake W
authors.initials: BW
authors.lastname: Erickson
authors.forename: Georg
authors.initials: G
authors.lastname: Fantner
authors.forename: Francesco
authors.initials: F
authors.lastname: Stellacci
authors.affiliation: §Department of Physics, Durham University, South Road, Durham DH1 3LE, United Kingdom.
authors.forename: Kislon
authors.initials: K
authors.lastname: Voïtchovsky
mesh_terms: D000327:Adsorption; D002119:Calcium Carbonate / Q000138:chemical synthesis / Q000737:chemistry*; D015394:Molecular Structure; D010316:Particle Size; D013229:Stearic Acids / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D013229:Stearic Acids; C031183:stearic acid; D002119:Calcium Carbonate