Geometrical Entanglement and Alignment Regulate Self-Organization in Active Ring Polymer Suspensions.

Area of Science:

• Soft Matter Physics
• Active Matter Systems
• Polymer Science

Background:

• Self-organization is a key phenomenon in active matter.
• Understanding the interplay between particle geometry and collective behavior is crucial.
• Previous studies have not fully explored entanglement's role in active ring systems.

Purpose of the Study:

• To investigate how orientational order and geometric entanglement in active ring suspensions are affected by density and confinement.
• To quantify ring entanglement and orientational order using novel metrics.
• To identify the self-organized states emerging in active ring systems.

Main Methods:

• Introduction of the 'wrapping number' to quantify pairwise ring interpenetration.
• Characterization of orientational order via alignment of normal vectors to osculating planes.
• Mutual-information analysis to determine correlations between alignment and wrapping number.

Main Results:

• Both wrapping number and alignment differentiate active from passive systems.
• A significant correlation exists between ring alignment and wrapping number in active conditions.
• Self-organization shows nonmonotonic dependence on entanglement: moderate wrapping stabilizes contacts, while excessive entanglement disrupts alignment.

Conclusions:

• A competition between entanglement and alignment exists, driven by the need for planar conformations for stacking.
• The findings suggest that out-of-equilibrium effects can regulate entanglement in polymer systems.
• This microscopic mechanism may have broader implications for understanding self-organization in various soft matter systems.