Activity-driven polymer knotting for macromolecular topology engineering

Area of Science:

• Polymer Chemistry
• Soft Matter Physics
• Materials Science

Background:

• Macromolecules can exhibit unique properties when adopting knotted structures.
• Engineering specific macromolecular knots remains a significant challenge in polymer science.

Purpose of the Study:

• To investigate the efficient generation of knots in active polymer systems.
• To explore the potential of active polymers in macromolecular topology engineering.

Main Methods:

• Simulating actively reptative polymers with one anchored end.
• Analyzing the effects of giant conformation fluctuations and reptative motion on knot formation.
• Investigating the behavior of active polymers grafted onto passive polymers.

Main Results:

• Active polymer systems unexpectedly generate knots efficiently through self-knotting.
• Formed knots migrate to the anchoring point via a nonequilibrium ratchet effect.
• Active polymers act as self-propelling soft needles, transferring or braiding knots onto passive polymers.
• Intermolecular bridging knots can be created between passive polymers using active needles.

Conclusions:

• Nonequilibrium effects are crucial for modifying polymer system dynamics and enabling knot engineering.
• Active polymer systems offer a novel approach for controlled macromolecular topology.
• This work has potential applications in advanced materials and nanotechnology.