Roughness-dependent clogging of particle suspensions flowing into a constriction

Area of Science:

• Fluid dynamics
• Materials science
• Colloid science

Background:

• Particle suspensions in constricting channels can either flow or clog.
• Clogging impacts industrial processes like printing and filtration, but also micro-separation.
• Previous research focused on flow velocity, concentration, and geometry, neglecting particle surface properties.

Purpose of the Study:

• To investigate the effect of particle surface roughness on clogging in microchannels.
• To understand how surface topography influences particle jamming behavior.
• To identify critical parameters for controlling clogging in particulate suspensions.

Main Methods:

• Synthesis of micron-sized silica particles with controlled surface roughness.
• Experimentation with pressure-driven flow of particle suspensions through a microchannel constriction.
• Systematic variation of particle velocity and volume fraction to observe clogging events.

Main Results:

• A direct correlation was found between particle surface roughness and flow rate.
• Increased surface roughness led to a higher likelihood of clogging.
• Rougher particles jammed more readily at slower flow velocities.

Conclusions:

• Particle surface roughness is a crucial, previously underappreciated factor in suspension clogging.
• Surface properties must be considered alongside flow and geometry for effective process control.
• Findings are vital for optimizing particulate suspension applications and designing microfluidic devices.