Fast Increase of Nanofluidic Slip in Supercooled Water: the Key Role of Dynamics

Abstract

Nanofluidics is an emerging field offering innovative solutions for energy harvesting and desalination. The efficiency of these applications depends strongly on liquid-solid slip, arising from a favorable ratio between viscosity and interfacial friction. Using molecular dynamics simulations, we show that wall slip increases strongly when water is cooled below its melting point. For water on graphene, the slip length is multiplied by up to a factor of five and reaches $230$nm at the lowest simulated temperature, $T\sim 225$K; experiments in nanopores can reach much lower temperatures and could reveal even more drastic changes. The predicted fast increase in water slip can also be detected at supercoolings reached experimentally in bulk water, as well as in droplets flowing on anti-icing surfaces. We explain the anomalous slip behavior in the supercooled regime by a decoupling between viscosity and bulk density relaxation dynamics, and we rationalize the wall-type dependency of the enhancement in terms of interfacial density relaxation dynamics. By providing fundamental insights on the molecular mechanisms of hydrodynamic transport in both interfacial and bulk water in the supercooled regime, this study is relevant to the design of anti-icing surfaces and it also paves the way to explore new behaviors in supercooled nanofluidic systems.

8 pages, 4 figures

References in corpus (13)

• Ultrathin graphene-based membrane with precise molecular sieving and ultrafast solvent permeation
• Friction of Water on Graphene and Hexagonal Boron Nitride from ab initio Methods: Very Different Slippage Despite Very Similar Interface Structures
• Molecular streaming and its voltage control in ångström scale channels
• Liquid-solid slip on charged walls: dramatic impact of charge distribution
• What controls thermo-osmosis? Molecular simulations show the critical role of interfacial hydrodynamics
• Electro-hydrodynamics near Hydrophobic Surfaces
• Ionic Coulomb blockade as a fractional Wien effect
• Molecular dynamics study of nanoconfined TIP4P/2005 water: how confinement and temperature affect diffusion and viscosity
• Emergence of molecular friction in liquids: bridging between the atomistic and hydrodynamic pictures
• Stick-Slip Control in Nanoscale Boundary Lubrication by Surface Wettability
• Giant thermoelectric response of nanofluidic systems driven by water excess enthalpy
• Viscoelasticity induced onset of slip at the wall for polymer fluids
• Equilibrium measurement method of slip length based on fluctuating hydrodynamics