Dataset Information

Ion dissolution mechanism and kinetics at kink sites on NaCl surfaces.

ABSTRACT: Desolvation barriers are present for solute-solvent exchange events, such as ligand binding to an enzyme active site, during protein folding, and at battery electrodes. For solution-grown crystals, desolvation at kink sites can be the rate-limiting step for growth. However, desolvation and the associated kinetic barriers are poorly understood. In this work, we use rare-event simulation techniques to investigate attachment/detachment events at kink sites of a NaCl crystal in water. We elucidate the desolvation mechanism and present an optimized reaction coordinate, which involves one solute collective variable and one solvent collective variable. The attachment/detachment pathways for Na⁺ and Cl^- are qualitatively similar, with quantitative differences that we attribute to different ion sizes and solvent coordination. The attachment barriers primarily result from kink site desolvation, while detachment barriers largely result from breaking ion-crystal bonds. We compute ion detachment rates from kink sites and compare with results from an independent study. We anticipate that the reaction coordinate and desolvation mechanism identified in this work may be applicable to other alkali halides.

SUBMITTER: Joswiak MN

PROVIDER: S-EPMC5789917 | biostudies-literature | 2018 Jan

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Ion dissolution mechanism and kinetics at kink sites on NaCl surfaces.

Joswiak Mark N MN Doherty Michael F MF Peters Baron B

Proceedings of the National Academy of Sciences of the United States of America 20180108 4

Desolvation barriers are present for solute-solvent exchange events, such as ligand binding to an enzyme active site, during protein folding, and at battery electrodes. For solution-grown crystals, desolvation at kink sites can be the rate-limiting step for growth. However, desolvation and the associated kinetic barriers are poorly understood. In this work, we use rare-event simulation techniques to investigate attachment/detachment events at kink sites of a NaCl crystal in water. We elucidate t ...[more]

PMID: 29311331

Similar Datasets

Project description:Scale mineral deposition is a critical problem that hinders the daily production of oil and gas fields. Chemical removal of these scales, based on the scale type, is common. In this paper, borax and diethylene tremaine penta acetic (DTPA) acid-based formulations are used for the removal of sulfides, carbonates, and sulfate scales. In particular, the dissolution rates of sulfide (pyrite, pyrrhotite, and galena), sulfate (celestite and barite), and carbonate (calcite) scales were investigated in a rotating disc apparatus at typical well conditions. Scanning electron microscopy-energy-dispersive X-ray and X-ray diffraction analyses were performed for characterizing scale composition and type. The effect of temperature, scale type, and formulation on the dissolution rate is studied. Even though borax formulation has been developed for the sulfide scale removal, it showed a high dissolution rate for the carbonate scale (7.23 × 10-7 mol·L-1·s-1·cm-2). For the sulfide scale, the highest dissolution in borax formulation was obtained with galena (lead sulfide, PbS), followed by pyrrhotite, and the lowest dissolution was reported for pyrite (1.55 × 10-8 mol·L-1·s-1·cm-2). Borax formulation was found to be inefficient in the removal of sulfate scales with a dissolution rate lower than carbonate and sulfide scales by 3 and 2 orders of magnitude, respectively. Similarly, DTPA-based formulation has yielded the highest dissolution for the carbonate scale (7.98 × 10-6 mol·L-1·s-1·cm-2). However, for sulfate, DTPA-based formulation showed better performance than borax. The increase in temperature leads to an increase in the dissolution rate for almost all types of scales; however, DTPA-based formulation showed improved performance with temperature. Both formulations are efficient in removing sulfate- and sulfide-rich scales. The experimental results of DTPA have been validated by density functional theory calculations of binding energies between DTPA and metal ions present in the mixed scale.

Dataset Information

Ion dissolution mechanism and kinetics at kink sites on NaCl surfaces.

Publications

Ion dissolution mechanism and kinetics at kink sites on NaCl surfaces.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets