Dynamic squeezing of liquid bridge between two spherical particle surfaces

Area of Science:

• Physics
• Materials Science
• Fluid Mechanics

Background:

• Liquid bridges are fundamental to capillary phenomena in wet granular materials.
• Existing studies on static forces and stretching are insufficient for dynamic compression scenarios.
• Understanding solid-liquid interactions under compression is vital for mechanical modeling.

Purpose of the Study:

• Investigate the evolution of capillary forces in liquid bridges under dynamic squeezing.
• Provide insights into solid-liquid interaction mechanisms.
• Develop a basis for mechanical models of liquid bridges during compression.

Main Methods:

• Utilized ethylene glycol to minimize evaporation.
• Employed a liquid bridge force testing system for dynamic squeezing and static equilibrium experiments.
• Applied image processing to determine geometric parameters and analyze liquid bridge morphology and force (F_liq).

Main Results:

• Observed a three-stage geometric evolution in quasi-static liquid bridges due to contact angle hysteresis.
• Identified viscous forces as dominant under dynamic squeezing, significantly reducing F_liq.
• Found F_liq exhibited a two-stage growth pattern during equilibrium, stabilizing at a higher force, influenced by geometric changes.

Conclusions:

• Liquid bridge behavior under compression is complex, involving distinct stages and force dynamics.
• Dynamic squeezing and subsequent equilibrium lead to significant, geometry-dependent changes in liquid bridge forces.
• Findings offer critical data for refining models of wet granular materials under compressive loads.