Continuum and Atomistic Simulation of Electrically-Mediated Flow Through Nanometer Channels

In this thesis, we study fundamental issues in electrically-mediated fluid flow by performing a detailed comparison between atomistic and continuum simulations. Our results indicate that the molecular nature of the ion and water are important factors influencing the ion concentrations, velocity profiles and other fluid characteristics in nanochannels. As the continuum theories based on the Poisson-Boltzmann and the Navier-Stokes equations account for the various intermolecular interactions in a mean-field fashion, they fail to predict the fluid/ion characteristics accurately. In addition, fluids or electrolytes confined in nanochannels exhibit anomalous behavior, which cannot be explained by the classical theories. Our results also indicate that if the critical channel dimension is larger than ten molecular diameters, then the classical theory can be used to describe fluid/ion characteristics in the central part of the channel, but an atomistic approach is necessary to resolve a few molecular diameters near the channel wall. As a final result, we present embedding multiscale methods which efficiently combine an atomistic model near the channel wall with the classical theory for the central part of the channel. The multiscale models can also be used to explain the anomalous behavior observed in electrically-mediated nanofluidic transport.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Mechanical Engineering

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2004

Author dc:creator

• Qiao, Rui

Contributors dc:contributor

• Aluru, Narayana R.

• Chemistry, Physical

Language dc:language

eng

Identifier

(MiAaPQ)AAI3153404

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/83817