296 research outputs found
Water thermophoresis in carbon nanotubes: the interplay between thermophoretic and friction forces
MD simulations show that the thermophoretic force is not velocity dependent while the friction force increases with the droplet speed.</p
Publisher's Note: "Thermally driven molecular linear motors: A molecular dynamics study" [J. Chem. Phys. 131, 241104 (2009)]
Effect of charge inversion on Poiseuille flow of multivalent electrolyte solutions in nanochannels: an atomistic study
Carbon Nanotubes as Thermally Induced Water Pumps
Thermal Brownian motors (TBMs) are nanoscale machines that exploit thermal fluctuations to provide useful work. We introduce a TBM-based nanopump which enables continuous water flow through a carbon nanotube (CNT) by imposing an axial thermal gradient along its surface. We impose spatial asymmetry along the CNT by immobilizing certain points on its surface. We study the performance of this molecular motor using molecular dynamics (MD) simulations. From the MD trajectories, we compute the net water flow and the induced velocity profiles for various imposed thermal gradients. We find that spatial asymmetry modifies the vibrational modes of the CNT induced by the thermal gradient, resulting in a net water flow against the thermal gradient. Moreover, the kinetic energy associated with the thermal oscillations rectifies the Brownian motion of the water molecules, driving the flow in a preferred direction. For imposed thermal gradients of 0.5-3.3 K/nm, we observe continuous net flow with average velocities up to 5 m/s inside CNTs with diameters of 0.94, 1.4, and 2.0 nm. The results indicate that the CNT-based asymmetric thermal motor can provide a controllable and robust system for delivery of continuous water flow with potential applications in integrated nanofluidic devices
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