Atomic-level viscosity distribution in the hydration layer

Abstract

Viscosity of the solvation structures is crucial for the development of energy-efficient biochemical and electrochemical devices. Elucidating their subnanoscale distributions can cause the formation of a sustainable energy society. Here, we visualize the three-dimensional damping distribution on a CaCO3 surface composing binary ion species using ultra-low-noise frequency-modulation atomic force microscopy. With the support from molecular dynamics simulation, we found a strikingly large damping at the calcium sites, which demonstrates the capability of this methodology to visualize molecular-scale viscosity in the hydration layers, which will expedite the evolutions of various functional devices.