Dissipative response of driven bead-spring-dashpot chains

Abstract

The work dissipated in pulling a polymer chain with internal friction is numerically calculated by considering a sequence of $N$ 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. {While the dissipation increases with $N$ for chains without internal friction, the relationship between the dissipation and $N$ for chains with internal friction depends on the pulling trap stiffness. For chains with internal friction, the dissipation \textit{decreases} (increases) with $N$ as the the pulling trap stiffness is \textit{increased} (decreased), keeping all other parameters constant. Therefore, unlike in the case of a single-mode spring-dashpot ($N=1$) for which a simple relationship exists between the damping coefficient of the dashpot and the dissipated work [as shown in Phys. Rev. Res. \textbf{2}, 013331 (2020)], the same is not true for the general case of $N>1$ due to the stiffness-dependent dissipative response of bead-spring-dashpot chains.