(720e) Interfacial-Hydration Fundamentals: Molecular-Dynamics Insights from the Nanoscale

The nature and importance of hydration is underpinned, to a large extent, by the peculiarities of hydrogen-bonding of water at, and near, interfaces with a disparate variety of materials (including vacuum). Here, using molecular-dynamics simulation, we detail a panoply of surface-water interactions, covering a broad suite of systems, ranging from water nano-clusters in No Man’s Land and nano-bubbles, to solvated proteins, gas hydrates and metal-oxide surfaces. We uncover some universal features of translational- and rotational-motion suppression in hydration layers, together with heterogeneity of experience therein in terms of residence times and hydrogen-bond interactions with disparate surfaces, varying in curvature and local hydrophobic/hydrophilic chemical ‘identity’. The role of temperature is also discussed as a key determinant of the precise details of water interactions with these surfaces. Finally, the nature of externally-applied electric and electromagnetic fields as an agent to alter the dynamics and energetics of hydration across a broad suite of surfaces is discussed, with radically contrasting outcomes between dipolar and hydrogen-bond kinetics in hydration-water molecules in static and time-varying external electric fields.