Study on Coagulation Kinetics of Disk-like Particles under Simple Shear Flow

Area of Science:

• Fluid dynamics
• Particle physics
• Materials science

Background:

• Understanding particle interactions is crucial for colloid science and materials engineering.
• Shear flow influences the dynamics and aggregation of suspended particles.
• Disk-like particles exhibit unique behaviors due to their anisotropic shape.

Purpose of the Study:

• To theoretically investigate the coagulation of disk-like particles in a shear flow.
• To analyze the influence of liquid viscosity and particle aspect ratio on coagulation kinetics.
• To identify dominant collision modes and their relation to particle interactions.

Main Methods:

• A theoretical approach was employed to model particle collisions.
• Hydrodynamic and van der Waals interactions were included.
• Boundary integral formulation was used for hydrodynamic interaction calculations.
• Kinetic constants of coagulation were determined considering particle orientation and flow flux.

Main Results:

• Coagulation kinetic constant decreases with increasing liquid viscosity, reducing to ~1/3 at 1 Pa·s.
• Edge-edge collision mode is frequently observed for aspect ratios between 0.1 and 0.4.
• Particle aspect ratio and liquid viscosity significantly impact coagulation dynamics.

Conclusions:

• Liquid viscosity is a critical factor in controlling disk-like particle coagulation under shear flow.
• The prevalence of edge-edge collisions highlights the importance of particle shape in aggregation processes.
• These findings contribute to the understanding of colloidal system behavior in industrial applications.