Comparison of water nanodroplet properties on different graphite-based substrates

• Published in: AIP advances Vol. 11; no. 3; pp. 035009 - 035009-7
• Main Authors: Goswami, Monojoy, Kumar, Navin, Li, Yuzhan, Rios, Orlando, Akamo, Damilola O., Hirschey, Jason, LaClair, Tim J., Gluesenkamp, Kyle R.
• Format: Journal Article
• Language: English
• Published: Melville American Institute of Physics 01-03-2021; American Institute of Physics (AIP); AIP Publishing LLC
• Subjects: Carbon; Graphite; Hydration; Molecular dynamics; Molecular structure; Morphology; Properties (attributes); Substrates; Water chemistry; Water distribution; Water engineering
• ISSN: 2158-3226; 2158-3226
• DOI: 10.1063/5.0042414

The molecular structure and dynamics of water differ considerably at various interfaces. We compare the interfacial water structure–property relationship on three different carbon substrates, namely, amorphous carbon, compressed expanded natural graphite, and pure graphite by utilizing atomistic molecular dynamics simulations. The effect of different substrates on the structural and dynamical properties of water can readily be observed. The density distributions parallel and normal to the substrates show oblate droplet structures. The normal to the substrate water distribution shows a strong hydration layer at the interface that does not vary with substrates. However, the disparity in the structure and dynamics on three different substrates shows that the surface morphologies of the substrates are critical for determining nanoscale water properties. Furthermore, it is observed that the formation of an interfacial water layer or the hydration layer is a direct consequence of both water “confinement” at the nanoscale and “attraction” between water molecules and the carbon substrates.