Modeling dense fluid flow through single- and multi-layer nanoporous carbon membranes

We study flow through single- and multi-layer nanoporous carbon membranes close to the steric exclusion limit, for applications to mixture separations. Particular emphasis is paid to the Sampson component of the flow, which is known to not admit a slip-corrected solution. Comparisons between molecular dynamics and finite element simulations suggest that deviations from the Sampson result as the steric limit is approached can be explained by the finite atomic size, which allows introduction of slip by regularizing the infinitely thin membrane and introduces an effective pore size. Our model is extensively validated by molecular dynamics simulations of simple Lennard-Jones-type fluids, as well as short-chain hydrocarbon molecules.