Dynamics of a two-dimensional active polymer chain with a rotation-restricted active head

Area of Science:

• Soft Matter Physics
• Polymer Dynamics
• Active Matter

Background:

• Active polymers, modeled as active Brownian particles (ABPs) with attached polymer chains, exhibit complex dynamics.
• The rotational dynamics of the ABP head group are crucial for the overall behavior of the active polymer system.

Purpose of the Study:

• To investigate the influence of resistance torque on the dynamics of a 2D active polymer.
• To elucidate the relationship between rotational restriction, persistence time, and propulsive diffusion.

Main Methods:

• Langevin dynamics simulations were employed to model the active polymer system.
• The study focused on analyzing the effects of self-propulsion force, rotational friction, and polymer length.

Main Results:

• Resistance torque significantly increases the rotational persistence time (τr) of the ABP.
• This persistence time changes non-monotonically with the rotational friction coefficient.
• A scaling relation, DP ∝ fs²τr/N²ηt², was established for the propulsive diffusion coefficient (DP).

Conclusions:

• The resistance torque's primary effect on active polymer dynamics is mediated by changes in rotational persistence time.
• Rotational persistence time is identified as a critical factor governing the diffusion of active polymers.
• The study provides insights into how external torques can control the diffusive behavior of active polymer systems.