Electrically Mediated Water Flow in Nanochannels

Abstract

Motivated by electrowetting-based flow control in nano-systems, water transport in graphene nanochannels is investigated. Molecular dynamics simulations of force-driven water flow in graphene nano-channels subjected to opposing surface charges respond to the electric field by reorientation of their dipoles. This creates flow asymmetry and surface charge dependent variations in the slip velocity and bulk viscosity. Beyond a certain threshold, electro-crystallization of water in nanochannels at room temperature is observed. The second part of the talk will focus on electroosmotic flow (EOF) of ionized water in silicon nanochannels in the Debye–Hückel regime. The onset of slip velocity within the thin electrical double layer region and its effects on EOF will be presented. Influences of increased surface charge density in the intermediate and flow-reversal regimes will also be discussed and the results will be compared with relevant high-order continuum models that include the over-screening and crowding effects.