Flow and structure of fluids in functionalized nanopores

Abstract

We investigate through non-equilibrium molecular dynamics simulations the structure and flow of fluids in functionalized nanopores. The nanopores are modeled as cylindrical structures with solvophilic and solvophobic sites. Two fluids are modeled. The first is a standard Lennard Jones fluid. The second one is modeled with an isotropic two-length scale potential, which exhibits in bulk water-like anomalies. Our results indicate distinct dependence of the overall mass flux for each species of fluid with the number of solvophilic sites for different nanotubes’ radii. Also, the density and fluid structure are dependent on the nanotube radius and the solvophilic properties of the nanotube. This indicates that the presence of a second length scale in the fluid–fluid interaction will lead to distinct behavior. Also, our results show that chemically functionalized nanotubes with different radii will have distinct nanofluidic features. Our results are explained on the basis of the characteristic scale fluid properties and the effects of nanoconfinement.