Atomic-level insights into nano-salt droplets wetting on the MgO surface using molecular dynamics simulations. (1st May 2020)

• Record Type: Journal Article
• Authors: Li, Xin; Zhang, Chi; Wang, Junsheng; Huang, Houbing; Wang, Shuo
• Is Part Of: Corrosion science. Volume 167(2020)
• Publication Date: 2020-05-01
• Subjects: Wettability -- Aqueous NaCl solutions -- Hydration monolayer -- Ion hydration -- MgO; Corrosion and anti-corrosives -- Periodicals; 620.11223
• DOI: 10.1016/j.corsci.2020.108549
• Languages: English
• ISSNs: 0010-938X

Abstract

Graphical abstract: The distribution of hydrogen bond density along z -axis at different salt concentrations and the images inside the graph show the criteria of hydrogen bonds. Highlights: The wetting mechanism of NaCl solution on the surface of MgO is investigated. Ion hydration breaks the hydrogen bond network in the hydration layer and bulk. The orientation of water molecules can be changed by ion hydration. Ion hydration leads to the ordered structure of first hydration layer. The contact angle increases almost linearly with the salt concentration. Abstract: The effects of NaCl solution concentrations on the water wettability of the MgO surface have been studied using molecular dynamics simulations. We find that ion hydration has a strong ability to dominate the structure of water network in the hydration layer. It can transform the orientation of water OH bonds, and reconstruct an ordered water network in the first layer, which in turn reduces the density of inter-layer hydrogen bonds. This further results in weak interactions between the first hydration layer and the actual droplet above the hydration layer, eventually increasing the hydrophobicity of the MgO(001) surface and corrosion resistance.