Competition between collapse and breakup in nanometer-sized thin rings using molecular dynamics and continuum...

Area of Science:

• Fluid dynamics
• Surface science
• Nanotechnology

Background:

• Understanding fluid behavior at the nanoscale is crucial for various applications.
• Fluidic structures on solid surfaces can exhibit complex instabilities.
• The interplay between surface forces and fluid instabilities dictates assembly.

Purpose of the Study:

• To investigate the stability of nanometer-sized fluid annuli (rings) on a solid substrate.
• To determine whether these rings fragment into droplets or coalesce into a single drop.
• To identify the factors controlling the assembly dynamics of these fluid rings.

Main Methods:

• Utilizing atomistic molecular dynamics simulations to model fluid behavior at the atomic level.
• Employing a continuum model derived from the long-wave limit of Navier-Stokes equations.
• Comparing and validating results from both simulation approaches.

Main Results:

• Consistent outcomes were observed between molecular dynamics simulations and the continuum model.
• Identified characteristic dimension regimes that govern the assembly dynamics of fluid rings.
• Demonstrated that fluid rings can either break into droplets or collapse into a central drop.

Conclusions:

• The stability and breakup dynamics of nanometer fluid rings are influenced by substrate interactions and azimuthal curvature.
• Both atomistic and continuum modeling approaches provide reliable insights into these phenomena.
• Characteristic dimensions play a critical role in predicting whether fluid rings fragment or coalesce.