Using Acoustic Perturbations to Dynamically Tune Shear Thickening in Colloidal Suspensions

Area of Science:

• Rheology
• Colloid Science
• Acoustic Physics

Background:

• Colloidal suspensions are widely used in industry.
• Shear thickening behavior in these suspensions presents significant control challenges.
• Existing methods for controlling viscosity are often passive or limited.

Purpose of the Study:

• To investigate the use of acoustic perturbations for active control of shear thickening in colloidal suspensions.
• To understand the underlying mechanism of viscosity reduction via acoustic waves.
• To assess the applicability of this technique across different flow geometries.

Main Methods:

• Utilized piezoelectric transducers to generate acoustic perturbations.
• Applied acoustic waves to colloidal suspensions in the shear-thickening regime.
• Measured changes in suspension viscosity dynamically.

Main Results:

• Demonstrated dynamic tuning of suspension viscosity using acoustic perturbations.
• Observed a 'dethickening' effect attributed to the disruption of shear-induced force chains.
• Perturbation scale relative to particle roughness was identified as a key factor.

Conclusions:

• Acoustic perturbations offer a powerful method for active viscosity control in shear-thickening suspensions.
• The technique is adaptable to various industrial flow geometries.
• This approach provides new avenues for investigating suspension dynamics.