Header

UZH-Logo

Maintenance Infos

Fast increase of nanofluidic slip in supercooled water: the key role of dynamics


Herrero, Cecilia; Tocci, Gabriele; Merabia, Samy; Joly, Laurent (2020). Fast increase of nanofluidic slip in supercooled water: the key role of dynamics. Nanoscale, 12(39):20396-20403.

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 ∼ 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 dependence of the enhancement in terms of interfacial density relaxation dynamics. While 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, could help explain the subtle phase and dynamical behaviors of supercooled confined water, and paves the way to explore new behaviors in supercooled nanofluidic systems.

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 ∼ 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 dependence of the enhancement in terms of interfacial density relaxation dynamics. While 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, could help explain the subtle phase and dynamical behaviors of supercooled confined water, and paves the way to explore new behaviors in supercooled nanofluidic systems.

Statistics

Citations

Altmetrics

Downloads

2 downloads since deposited on 01 Feb 2021
2 downloads since 12 months
Detailed statistics

Additional indexing

Item Type:Journal Article, refereed, original work
Communities & Collections:07 Faculty of Science > Department of Chemistry
Dewey Decimal Classification:540 Chemistry
Scopus Subject Areas:Physical Sciences > General Materials Science
Uncontrolled Keywords:General Materials Science
Language:English
Date:1 January 2020
Deposited On:01 Feb 2021 16:07
Last Modified:02 Feb 2021 21:00
Publisher:Royal Society of Chemistry
ISSN:2040-3364
OA Status:Hybrid
Free access at:Publisher DOI. An embargo period may apply.
Publisher DOI:https://doi.org/10.1039/d0nr06399a
Project Information:
  • : FunderSNSF
  • : Grant IDPZ00P2_179964
  • : Project TitleAb Initio Nanofluidics: Electronic Structure and Transport Properties for Osmotic Energy Conversion

Download

Hybrid Open Access

Download PDF  'Fast increase of nanofluidic slip in supercooled water: the key role of dynamics'.
Preview
Content: Published Version
Filetype: PDF
Size: 1MB
View at publisher
Licence: Creative Commons: Attribution-NonCommercial 4.0 International (CC BY-NC 4.0)