Interparticle hydrogen bonding can elicit shear jamming in dense suspensions

Area of Science:

• Rheology
• Soft Matter Physics
• Materials Science

Background:

• Dense particle suspensions exhibit complex behaviors like discontinuous shear thickening (DST) and reversible shear jamming (SJ).
• A transition from hydrodynamic interactions to frictional contacts under stress drives these phenomena.
• Many experimental systems display DST but not SJ, limiting understanding and applications.

Purpose of the Study:

• To investigate the role of particle surface chemistry in enabling reversible shear jamming (SJ).
• To identify the specific mechanism responsible for eliciting SJ in dense suspensions.
• To provide a framework for designing suspensions with tunable jamming properties.

Main Methods:

• Utilized charge-stabilized polymer microspheres and cornstarch particles.
• Controlled interparticle hydrogen bond formation using different solvents.
• Quantified SJ propensity using tensile tests.
• Measured interparticle friction using atomic force microscopy.

Main Results:

• Demonstrated that interparticle hydrogen bond formation under shear is crucial for eliciting SJ.
• Showed that SJ is observable in systems designed to promote hydrogen bonding.
• Linked the propensity for SJ to enhanced interparticle friction.

Conclusions:

• Particle surface chemistry, specifically the ability to form hydrogen bonds, is a critical factor for observing reversible shear jamming.
• This finding advances the fundamental understanding of SJ mechanisms in dense suspensions.
• Opens new possibilities for designing non-Newtonian fluids with controllable jamming behavior.