Single species transport and self diffusion in wide single-walled carbon nanotubes

TY - JOUR

T1 - Single species transport and self diffusion in wide single-walled carbon nanotubes

AU - Mutat, T.

AU - Adler, J.

AU - Sheintuch, M.

N1 - Funding Information: Animations of the molecular transport have been extended into a stereoscopic 3D version in collaboration with H. Zilken at Juelich as part of the Technion-Juelich Umbrella cooperation and were presented at International Supercomputing Conference (ISC) 2010. We thank the Umbrella project for support. We acknowledge the European inititive for High Performance Computing (HPC-Europa) project for support of the computations on the Intel EM64T cluster at HLRS in Stuttgart under Grant No. RII3-CT-2003-506079. T.M. acknowledges support from the Leonard and Diane Sherman Foundation, and thanks H. Herrman for hospitality during the HPC-EUROPA visit. M.S. acknowledges the support of the US-Israel Binational Science Foundation.

PY - 2012/6/21

Y1 - 2012/6/21

N2 - We model and simulate gas flow through nanopores using a single-walled carbon nanotube model. Efficient protocols for the simulation of methane molecules in nanotubes are developed and validated for both the self-diffusivity, following a pulse perturbation, and for the transport diffusivity in an imposed concentration gradient. The former is found to be at least an order of magnitude lower than the latter, and to decline with increasing initial pressure, while the latter increases as the pressure gradient increases until it reaches an asymptotic value. Our previous analytic model, developed for single-file diffusion in narrow pores, is extended to wider pores for the case of single species transport. The model, which predicts the observed numerical results invokes four regimes of transport. The dominant transport is by ballistic motion near the wall in not too wide nanotubes when a pressure gradient or concentration is imposed; this mode is absent in the case of self-diffusion due to periodic boundary conditions. We also present results from systematic comparisons of flexible versus rigid tubes and explicit atom versus effective atomic potentials.

AB - We model and simulate gas flow through nanopores using a single-walled carbon nanotube model. Efficient protocols for the simulation of methane molecules in nanotubes are developed and validated for both the self-diffusivity, following a pulse perturbation, and for the transport diffusivity in an imposed concentration gradient. The former is found to be at least an order of magnitude lower than the latter, and to decline with increasing initial pressure, while the latter increases as the pressure gradient increases until it reaches an asymptotic value. Our previous analytic model, developed for single-file diffusion in narrow pores, is extended to wider pores for the case of single species transport. The model, which predicts the observed numerical results invokes four regimes of transport. The dominant transport is by ballistic motion near the wall in not too wide nanotubes when a pressure gradient or concentration is imposed; this mode is absent in the case of self-diffusion due to periodic boundary conditions. We also present results from systematic comparisons of flexible versus rigid tubes and explicit atom versus effective atomic potentials.

UR - http://www.scopus.com/inward/record.url?scp=84863760464&partnerID=8YFLogxK

U2 - 10.1063/1.4727759

DO - 10.1063/1.4727759

M3 - 文章

AN - SCOPUS:84863760464

SN - 0021-9606

VL - 136

JO - Journal of Chemical Physics

JF - Journal of Chemical Physics

IS - 23

M1 - 234902

ER -