Conformation and dynamics of a self-avoiding active flexible polymer.

Area of Science:

• Polymer Physics
• Soft Matter Physics
• Statistical Mechanics

Background:

• Active matter systems, such as polymers with self-propelled monomers, exhibit distinct behaviors compared to passive systems.
• Understanding the conformational and dynamic properties of active polymers is crucial for designing novel materials and understanding biological processes.

Purpose of the Study:

• To investigate the conformational and dynamic properties of a polymer composed of active Brownian particles.
• To elucidate the role of excluded-volume interactions in the observed physical behavior.
• To analyze the crossover in scaling behavior and relaxation dynamics.

Main Methods:

• Computer simulations of an active polymer model.
• Analysis of monomer radial distribution functions.
• Calculation of scattering times and energy contributions.
• Investigation of end-to-end distance scaling and relaxation times.

Main Results:

• The active polymer displays an initial shrinkage followed by swelling with increasing active force, attributed to excluded-volume interactions.
• A crossover from self-avoiding to Rouse behavior (scaling exponent ν_{a}≈1/2) is observed in the swelling regime.
• The polymer chain relaxes faster than a passive Rouse chain in intermediate force regimes.
• A power-law relationship (τ_{r}∼Pe^{-4/3}) describes relaxation time at large Péclet numbers.

Conclusions:

• Active Brownian particle polymers exhibit complex, non-monotonic behavior absent in passive counterparts.
• Excluded-volume interactions are key drivers of the observed shrinkage-swelling transition.
• The study provides insights into the fundamental physics governing active polymer dynamics and conformation.