• Rectification of flow rate in the system occurs under positive and nega tive voltage biases. Fluid vortices are observed near the nanopore base and the corner of the reservoir, which could be used to enhance mixing of solutes in RTILs. • Nonlinear variation of flow rate as a function of time during the constant current charging process origins from the formation of electrical double layers near the charged nanopore wall. • Results in this study could find applications in RTIL pumping, nanoflu idic circuits, and cross-scale measurements for EDL dynamics. Electric-field-driven flow and transport of room-temperature ionic liquids (RTILs) through nanopores underpin various applications, such as energy storage and nanopore sensing. In this work, we studied the flow of RTILs through a charged conical nanopore under electric fields using continuum simulations, in which a Landau-Ginzburg-type model was used to describe ion transport and the Navier-Stokes equation was used to predict the flow. We found a flow rectification phenomenon and fluid vortices in the system; fluid vortices were observed to occur near the nanopore base and the corner of the reservoir, which could be used to enhance the mixing of solutes in RTILs. In the initial constant-current charging process, nonmonotonic variations in flow rates through the system as a function of time were observed and traced to the formation of electrical double layers (EDLs) near the charged nanopore wall. This finding suggests a new method of using the flow rate as a macroscopic measure to detect EDL dynamics at the nanoscale, a process that is difficult to visualize directly in experiments.
Li et al. (Sun,) studied this question.