Dissipative response of driven bead-spring-dashpot chains

TL;DR

This study numerically investigates how internal friction affects energy dissipation in driven bead-spring-dashpot chains, revealing that dissipation decreases with chain length under high trap stiffness and deviates from linearity with internal friction as the chain grows.

Contribution

It provides detailed analysis of dissipation behavior in bead-spring-dashpot chains, extending understanding beyond the N=1 case to chains with multiple elements under various conditions.

Findings

Dissipation decreases with chain length at high trap stiffness.

Relationship between dissipation and internal friction becomes nonlinear as N increases.

Closed-form expression for dissipation is only valid for N=1.

Abstract

The work dissipated in pulling a polymer chain with internal friction is numerically calculated by considering a sequence of $N$ bead-spring-dashpots tethered at one end and being pulled at the other using a harmonic trap via linear and symmetric protocols. The variation of the dissipation with the chain length, pulling trap stiffness, and the internal friction parameter are examined in detail for both the protocols. In the limit of high trap stiffness: (i) the dissipation $decreases$ with $N$ for chains with internal friction, keeping all other parameters constant, and (ii) the relationship between the dissipation and internal friction parameter deviates from linearity as $N$ is increased. Consequently, a closed-form expression between the dissipated work in driving a chain of spring-dashpots and the damping coefficient of a single dashpot can be written only for the case of $N = 1$ [as shown in Phys. Rev. Res. $\mathbf{2}$, 013331 (2020)] and not for the general case of $N > 1$.