The Force Required to Detach a Rotating Particle from a Liquid-Fluid Interface

Area of Science:

• Fluid dynamics
• Colloid and surface science

Background:

• Capillary adhesion quantifies particle-interface interactions.
• Existing models for detachment force exclude particle rotation.
• Understanding rotational effects is key for accurate adhesion measurements.

Purpose of the Study:

• Derive analytical expressions for detachment force of rotating particles.
• Investigate the influence of particle rotation on capillary adhesion.
• Quantify the reduction in detachment force due to rotation.

Main Methods:

• Developed analytical models for rotating spherical particle detachment.
• Incorporated contact angle hysteresis into theoretical framework.
• Calculated detachment forces for specific particle-fluid systems.

Main Results:

• Rotation reduces the detachment force for particles with contact angle hysteresis.
• A polydimethylsiloxane particle at a water-air interface showed a 25% lower detachment force when rotating.
• Analytical expressions accurately predict the effect of rotation on adhesion.

Conclusions:

• Particle rotation is a critical factor influencing capillary adhesion.
• The derived theory provides a more comprehensive understanding of particle detachment.
• This research has implications for manipulating particles at fluid interfaces.