Transport of neutral and charged nanorods across varying-section channels

TL;DR

This study investigates how the geometry and charge of nanorods influence their transport through channels with varying cross-sections, providing insights into controlling and separating such particles based on their properties.

Contribution

The paper introduces a systematic approximation approach to relate local diffusion coefficients to channel geometry and rod charge, predicting permeability for diverse nanorod parameters.

Findings

Transport of charged rods is geometry-dependent.

Permeability varies non-monotonically with rod charge.

Channel shape and rod charge can be tuned for separation.

Abstract

We study the dynamics of neutral and charged rods embedded in varying-section channels. By means of systematic approximations, we derive the dependence of the local diffusion coefficient on both the geometry and charge of the rods. This microscopic insight allows us to provide predictions for the permeability of varying-section channels to rods with diverse lengths, aspect ratios and charge. Our analysis shows that the dynamics of charged rods is sensitive to the geometry of the channel and that their transport can be controlled by tuning both the shape of the confining walls and the charge of the rod. Interestingly, we find that the channel permeability does not depend monotonically on the charge of the rod. This opens the possibility of a novel mechanism to separate charged rods.