Pore Morphology Determines Spontaneous Liquid Extrusion from Nanopores

Area of Science:

• Nanotechnology
• Materials Science
• Physical Chemistry

Background:

• Controlling the behavior of nanoconfined liquids is crucial for various applications.
• Spontaneous extrusion of nonwetting liquids from nanopores is a key phenomenon.
• Pore morphology's role in this extrusion is not fully understood.

Purpose of the Study:

• To investigate the effect of pore morphology on the spontaneous extrusion of nonwetting liquids from nanopores.
• To understand the underlying mechanisms governing liquid extrusion based on pore structure.
• To identify methods for controlling liquid extrusion via engineered pore characteristics.

Main Methods:

• High-pressure water intrusion-extrusion experiments on porous materials.
• Macroscopic capillary models.
• Molecular dynamics simulations.
• Mercury intrusion experiments to confirm generality.

Main Results:

• Extrusion behavior is highly sensitive to pore morphology, including small-scale roughness and interconnections.
• Similar nominal pore diameters and hydrophobicity can exhibit qualitatively different extrusion behaviors.
• The mechanism is generic for nonwetting liquids and fundamentally linked to pore topology.

Conclusions:

• Pore topology and internal morphology are critical determinants of nonwetting liquid extrusion from nanopores.
• This understanding allows for rational design of heterogeneous systems for nanofluidic and energy applications.
• Tailoring pore morphology offers a pathway to control liquid extrusion behavior.