How important are fluctuations in the treatment of internal friction in polymers?

Abstract

The Rouse model with internal friction (RIF), a widely used theoretical framework to interpret the effects of internal friction on conformational transitions in biomolecules, is shown to be an approximate treatment that is based on preaveraging internal friction. By comparison with Brownian dynamics simulations of an exact coarse-grained model that incorporates fluctuations in internal friction, the accuracy of the preaveraged model predictions is examined both at and away from equilibrium. While the two models predict intrachain autocorrelations that approach each other for long enough chain segments, they differ in their predictions for shorter segments. Furthermore, the two models differ qualitatively in their predictions for the chain extension and viscosity in shear flow, which is taken to represent a prototypical out-of-equilibrium condition.

24 pages, 10 figures

References in corpus (6)

• Non-Markovian polymer reaction kinetics
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• Universal scaling and characterisation of gelation in associative polymer solutions
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Cited by in corpus (3)

• Dilute polymer solutions under shear flow: comprehensive qualitative analysis using a bead-spring chain model with a FENE-Fraenkel spring
• Shear viscosity for finitely extensible chains with fluctuating internal friction and hydrodynamic interactions
• Rouse model with fluctuating internal friction