Conformational properties of active semiflexible polymers

TL;DR

This paper theoretically investigates how active noise influences the conformational behavior of semiflexible polymers, revealing activity-dependent relaxation, shrinkage, and swelling phenomena with implications for polymer dynamics.

Contribution

It introduces a continuous Gaussian semiflexible polymer model incorporating finite extensibility to analyze activity effects on polymer conformations.

Findings

Relaxation times strongly depend on activity levels.

Polymers transition from bending-elasticity-dominated to flexible behavior with increased activity.

Active noise causes significant polymer shrinkage and eventual swelling at high activity.

Abstract

The conformational properties of flexible and semiflexible polymers exposed to active noise are studied theoretically. The noise may originate from the interaction of the polymer with surround- ing active (Brownian) particles or from the inherent motion of the polymer itself, which may be composed of active Brownian particles. In the latter case, the respective monomers are indepen- dently propelled in directions changing diffusively. For the description of the polymer, we adopt the continuous Gaussian semiflexible polymer model. Specifically, the finite polymer extensibility is taken into account which turns out to be essentially for the polymer conformations. Our analytical calculations predict a strong dependence of the relaxation times on the activity. In particular, semi- flexible polymers exhibit a crossover from a bending-elasticity-dominated to the flexible-polymer dynamics with increasing activity. This leads to a significant noise-induced polymer shrinkage over a large range of self-propulsion velocities. For large activities, the polymers swell and their extension becomes comparable to the contour length. The scaling properties of the mean square end-to-end distance with respect to the polymer length and monomer activity are discussed.