Hydration layer structures on calcite facets and their roles in selective adsorptions of biomolecules: a molecular dynamics study

The selective adsorptions of biomolecules onto crystal faces are the key issues in the studies of biomineralization. Frequently, the adsorption processes are understood by using the direct binding model between organic compounds and inorganic crystals during the molecular dynamic studies. However, w...

Full description

Saved in:
Bibliographic Details
Published in:The Journal of chemical physics 2013-12, Vol.139 (23), p.234705-234705
Main Authors: Zhu, Beibei, Xu, Xurong, Tang, Ruikang
Format: Article
Language:English
Subjects:
Acrylic acid
Adsorption
Biomineralization
Biomolecules
Calcite
Calcium Carbonate - chemistry
Carboxyl group
Crystal structure
Dimers
Free energy
Hydration
Hydrogen Bonding
Molecular dynamics
Molecular Dynamics Simulation
Organic compounds
Surface chemistry
Water - chemistry
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The selective adsorptions of biomolecules onto crystal faces are the key issues in the studies of biomineralization. Frequently, the adsorption processes are understood by using the direct binding model between organic compounds and inorganic crystals during the molecular dynamic studies. However, water molecules near crystals always exhibit intense ordering and preferential orientation to form structured hydration layer. By using the adsorption of poly acrylic acid oligomer, acrylic acid (AA) dimer, onto calcite as an example, we demonstrate that the induced hydration layers contribute significant effects on the organic-inorganic interactions. In particular, on calcite (104) plane, two carboxyl groups of AA dimer both interact with the crystal but the molecule has to compete with water due to the well-structured hydration layer. On (110) plane, although only one carboxyl group of AA dimer interacts with this surface, the water layer is relatively loose so that the molecule can easily replace water. With a consideration of the hydration layer, our free energy analysis indicates that AA dimer has a stronger interaction with (110) face than with (104) face, which is consistent with the experimental observations. The study follows that the attachment of organic additive onto inorganic crystal facet is greatly mediated by near-surface hydration layers, and therefore, the critical role of structured water layers must be taken into account in the understanding of biomineralization interfaces.
ISSN:0021-9606
1089-7690
DOI:10.1063/1.4848696