Foam drainage in the presence of solid particles

Area of Science:

• Colloid and Surface Science
• Fluid Dynamics
• Materials Science

Background:

• Foam stability and liquid drainage are crucial in industrial processes like froth flotation.
• Understanding liquid flow in foams containing solid particles is essential for optimizing separation efficiency.

Purpose of the Study:

• To investigate the impact of partially hydrophobic silica particles on liquid drainage in foams stabilized by cationic surfactants.
• To elucidate the mechanism by which solid particles alter foam permeability and drainage regimes.

Main Methods:

• Forced drainage experiments were performed on foams containing CTAB surfactant and silica particles.
• Foam drainage equations were applied to simulate experimental data and interpret flow behavior.
• The influence of particle hydrophobicity and concentration on foam network confinement was analyzed.

Main Results:

• Even small amounts of solid particles drastically decrease foam permeability.
• Solid particles induce a transition from node-dominated to Plateau border-dominated drainage regimes.
• Particle presence increases interface rigidity and viscous losses in Plateau borders, reducing overall permeability.

Conclusions:

• Solid particles significantly impede liquid flow in foams, altering drainage dynamics.
• The findings provide insights into optimizing froth flotation by controlling particle-liquid interactions.
• The study generalizes theories on particle effects in foam drainage for three-phase systems.