Gated flow in nanopores for liquid-liquid separation

The nanopores with small radii (R) and long axial lengths (l) were found to be on or off for the fluid flow, dependent on the external power loss. The value of R may be no more than 1nm, and the ratio l/R can be on the scales 1.0E+3 or 1.0E+4. In the case of a small power loss, no wall slippage occurs and the flow resistance of the nanopore is huge so that the flow rate through the nanopore is as small as negligible. When the power loss on the nanopore is high enough, the wall slippage occurs and the flow resistance of the nanopore approaches to vanishing so that the flow rate through the nanopore is large. These functions are important for the liquid-liquid separation by using nanoporous filtration membranes. For the two mixed liquids, if the critical power losses on the nanopore for wall slippage is greatly different, one liquid can smoothly flow through the nanopore while the other liquid is impeded from flowing through it when the magnitude of the power loss exerted on the nanopore is between the two critical power losses for wall slippage.