The impact range for smooth wall-liquid interactions in nanoconfined liquids

Area of Science:

• Condensed matter physics
• Materials science
• Computational chemistry

Background:

• Bulk and nanoconfined liquids display distinct physical properties.
• Nanoconfined liquids exhibit phenomena like stratification and position-dependent relaxation.
• Recent computer simulations suggest similarities between bulk and nanoconfined liquids.

Purpose of the Study:

• To investigate microscopic similarities between bulk and nanoconfined liquids.
• To determine conditions under which bulk and nanoconfined liquid interactions are comparable.
• To explore the role of liquid properties in determining interaction ranges.

Main Methods:

• Molecular dynamics computer simulations.
• Simulation of four distinct nanoconfined liquids: Lennard-Jones, Kob-Andersen mixture, asymmetric dumbbell, and Dzugutov liquid.
• Analysis of wall-liquid and liquid-liquid interaction ranges.

Main Results:

• Identical interaction ranges between bulk and nanoconfined liquids were observed for
• Roskilde simple
• liquids.
• This similarity holds when liquids exhibit strong correlations between virial and potential-energy fluctuations.
• Interactions beyond the first coordination shell become negligible for wall-liquid interactions under these conditions.
• Non-Roskilde-simple liquids do not show this interaction range equivalence.

Conclusions:

• The concept of
• Roskilde simple
• liquids unifies the understanding of bulk and nanoconfined liquid interactions.
• The condition of strong virial-potential energy correlations is key to simplifying interaction models in nanoconfinement.
• This finding has implications for designing and simulating materials at the nanoscale.