Hierarchical Dynamics in Glassy Microgel Suspensions
Analysis
This paper investigates the dynamics of ultra-low crosslinked microgels in dense suspensions, focusing on their behavior in supercooled and glassy regimes. The study's significance lies in its characterization of the relationship between structure and dynamics as a function of volume fraction and length scale, revealing a 'time-length scale superposition principle' that unifies the relaxation behavior across different conditions and even different microgel systems. This suggests a general dynamical behavior for polymeric particles, offering insights into the physics of glassy materials.
Key Takeaways
- •Ultra-low crosslinked microgels act as fragile glass formers.
- •Dynamics are governed solely by effective volume fraction.
- •Anomalous glassy regime with accelerated relaxation times is observed.
- •A time-length scale superposition principle rationalizes relaxation times across different conditions.
- •The superposition principle applies to different microgel systems, suggesting general dynamical behavior.
“The paper identifies an anomalous glassy regime where relaxation times are orders of magnitude faster than predicted, and shows that dynamics are partly accelerated by laser light absorption. The 'time-length scale superposition principle' is a key finding.”