Thermally Driven Imbibition and Drainage Induced by Terraced Nanostructures

Abstract

Theoretical analysis and fully atomistic molecular dynamics simulations reveal a Brownian ratchet mechanism by which thermal fluctuations drive the net displacement of immiscible liquids confined in channels or pores with micro- or nanoscale dimensions. The thermally-driven displacement is induced by surface nanostructures with directional asymmetry and can occur against the direction of action of wetting or capillary forces. Mean displacement rates in molecular dynamics simulations are predicted via analytical solution of a Smoluchowski diffusion equation for the position probability density. The proposed physical mechanisms and derived analytical expressions can be applied to engineer surface nanostructures for controlling the dynamics of diverse wetting processes such as capillary filling, wicking, and imbibition in micro- or nanoscale systems.

References in corpus (3)

• Artificial Brownian motors: Controlling transport on the nanoscale
• Hydrodynamically enforced entropic trapping of Brownian particles
• Rotational Dynamics and Angular Locking of Nanoparticles at liquid Interfaces

Cited by in corpus (6)

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• Crossover from Shear-Driven to Thermally Activated Drainage of Liquid-Infused Microscale Capillaries
• Thermal fluctuations of an interface near a contact line
• A capillary diode for potential application in water-oil separation
• Diffusion in a rough potential: Dual-scale structure and regime crossovers
• Thermodynamics, Dynamics, and Kinetics of Nanostructured Fluid-Solid Interfaces