Effects of a pulsed electric field on the ejection of an electric-neutral nanocapsule out of a water-filled CNT barrel

Accurate manipulation of a nanoparticle is of great interest in various fields. This study developed a nanoejector model to preciously control the exit velocity (vout) of a nanocapsule from a water-filled nanotube barrel triggered by a pulsed electric field (EF). When switching on the EF, the water cluster below the capsule within the barrel has a sudden expansion along the tube axis, which propels the capsule out of the barrel. This study investigated the effects of the turn-on duration (s), the intensity (E) and the direction of the EF on final position and vout of the capsule by molecular dynamic simulations. We discovered that the axial intensity of a pulsed EF with s > 10 ps has minimal and maximal critical values (ECMin and ECMax, respectively) that guarantee the nanocapsule escaping from the barrel. ECMin decreases with increasing s. ECMax is independent of s > 10 ps, and the maximal value of vout (∼700 m/s) remains unchanged with E (>ECMax) and s (>10 ps). When the EF direction deviates from the nanotube axis, vout depends on the water structure under the EF. The conclusions are helpful for the design of a nano-ejector with a controllable exit velocity of a nanoparticle. © 2024 Elsevier B.V.