Cyclization and Relaxation Dynamics of Finite-Length Collapsed Self-Avoiding Polymers

Area of Science:

• Polymer physics
• Computational chemistry
• Statistical mechanics

Background:

• Polymer dynamics, including cyclization and relaxation, are fundamental to understanding polymer behavior.
• Chain length (N) significantly influences these dynamics.
• Previous studies established scaling laws for ideal polymer chains.

Purpose of the Study:

• To investigate the cyclization and relaxation dynamics of ideal and interacting polymers.
• To determine how chain length affects these dynamics.
• To analyze the behavior of self-avoiding and collapsed polymer chains.

Main Methods:

• Langevin simulations were employed to model polymer dynamics.
• Scaling theory was utilized to analyze the simulation data.
• Analysis focused on cyclization time (τ_cyc) as a function of chain length (N).

Main Results:

• For ideal polymer chains, the known scaling τ_cyc∼N^2 was recovered.
• For self-avoiding, slightly collapsed chains, a modified scaling of τ_cyc∼N^(5/3) was observed.
• Finite-length collapsed chains displayed different scaling behaviors, indicating dynamic multiscale phenomena.

Conclusions:

• The study elucidates distinct scaling behaviors for ideal versus collapsed polymer chains.
• A crossover between swollen and collapsed chain dynamics explains the observed multiscale behavior.
• Findings contribute to a deeper understanding of polymer chain dynamics under various conditions.