Manipulating mechanism of the electrokinetic flow of ionic liquids confined in silica nanochannel

•MD simulations of electrokinetic nanoconfined ionic liquids flow were performed.•The perpendicular configuration of cation at the silica surface was identified.•Modulating mechanism of external stimuli on electrokinetic flow of ionic liquids.•Developed quantitative relation between streaming current and external stimuli. The electrokinetic flow of ionic liquids (ILs) is widely used in electrochemical engineering applications. Herein, flow behavior and controlling mechanism of ILs driven by electrical field were investigated via molecular dynamics simulations. During the flow process, the cations prefer to allocate at the interface in a perpendicular configuration, while the anions tend to distribute randomly. In the interface region, the perpendicular cations and accumulated ILs would significantly enhance the local viscosity of ILs, which dominates the velocity distribution and total flux of the electrokinetic flow of confined ILs. Compared with the pressure and surface charging density, the nanochannel size would induce a larger impact on the average velocity, total flux, and streaming current of the electrokinetic flow of confined ILs. These quantitative results on the electrokinetic flow are crucial for the rational design of ILs-based devices or other chemical engineering processes.