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arXiv · 2305.06033

Non-monotonous translocation time of polymers across pores

Emanuele Locatelli·Valentino Bianco·Chantal Valeriani·Paolo Malgaretti
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Abstract

Polymers confined in corrugated channels, i.e. channels of varying amplitude, display {multiple local maxima and minima of the diffusion coefficient upon increasing their degree of polymerization $N$}. We propose a theoretical effective free energy for linear polymers based on a Fick-Jacobs approach. We validate the predictions against numerical data, obtaining quantitative agreement for {the effective free energy, the diffusion coefficient and the Mean First Passage Time}. Finally, we employ the effective free energy to compute the polymer lengths $N_{min}$ at which the diffusion coefficient presents a minimum: we find a scaling expression that we rationalize with a blob model. Our results could be useful to design porous adsorbers, that separate polymers of different sizes without the action of an external flow.

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Emanuele Locatelli, Valentino Bianco, Chantal Valeriani, Paolo Malgaretti. 2023-05-10. Non-monotonous translocation time of polymers across pores. https://doi.org/10.1103/physrevlett.131.048101

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