Abstract
A theoretical model is developed that describes nonlinear coupling between wall deformation and water and ion flows in a charged, deformable nanochannel whose viscoelasticity is governed by the Kelvin-Voigt model. Using continuum mean-field theories for mass and momentum conservation of the solid-liquid coupled system, a set of one-dimensional nonlinear partial differential equations is derived to capture the dynamics of wall deformations. For elastic but non-viscous walls undergoing small deformation, the problem simplifies to one of advection-diffusion type which is analytically solvable at first-order perturbation. Results unveil a rich coupling between the elasticity and charge distribution of the channel walls, which vanishes in the limit of weakly charged channels. This coupling significantly alters the quantitative response of the walls' relaxation dynamics and the channel's electrokinetic transport, thereby having important consequences for the description and understanding of electrokinetic flow through charged, viscoelastic media.
2 More- Received 14 March 2018
DOI:https://doi.org/10.1103/PhysRevE.98.053101
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