@article{liu_moore_roussel_gubbins_2010, title={Dual diffusion mechanism of argon confined in single-walled carbon nanotube bundles}, volume={12}, ISSN={["1463-9076"]}, DOI={10.1039/b927152j}, abstractNote={The adsorption and diffusion mechanisms of argon at 120 K were examined in a (25,0) single-walled carbon nanotube (SWCNT) bundle using a combination of Grand Canonical Monte Carlo and microcanonical molecular dynamics simulations. Interstices between the SWCNTs provided the most energetically favorable adsorption sites and filled completely at low relative pressure, followed by adsorption in the SWCNTs. We calculated the self-diffusivities from the average mean squared displacements of argon molecules. In both flexible and rigid bundles, we observed a bimodal diffusion mechanism, with single-file diffusion occurring in the interstitial sites and Fickian diffusion in the SWCNTs. Strong system size effects were observed in our simulations. The largest system sizes showed very little influence of the nanotube flexibility on the diffusion of argon even at the lowest pressures studied.}, number={25}, journal={PHYSICAL CHEMISTRY CHEMICAL PHYSICS}, author={Liu, Ying-Chun and Moore, Joshua D. and Roussel, Thomas J. and Gubbins, Keith E.}, year={2010}, pages={6632–6640} }
 @article{chen_moore_liu_roussel_wang_wu_gubbins_2010, title={Transition from single-file to Fickian diffusion for binary mixtures in single-walled carbon nanotubes}, volume={133}, ISSN={["1089-7690"]}, DOI={10.1063/1.3469811}, abstractNote={The transition from single-file diffusion to Fickian diffusion in narrow cylindrical pores is investigated for systems of rigid single-walled armchair carbon nanotubes, solvated with binary mixtures of Lennard-Jones fluids (Ar/Ne, Ar/Kr, and Ar/Xe). A range of effects is examined including the mixture concentration, the size ratio of the two components, and the nanotube diameter. The transition from single-file to Fickian diffusion in varying carbon nanotube diameters is analyzed in terms of the Fickian self-diffusivity and the single-file mobility of the mixture components. It is found that the single-file to Fickian carbon nanotube transition diameter is a unique property of the individual molecule’s diameter and remains unchanged regardless of the mixture composition. In applications of binary mixtures, each component may crossover from single-file to Fickian diffusion in a different carbon nanotube diameter, giving rise to bimodal diffusion in some nanotubes. This transition allows for one species to diffuse in single-file while the other diffuses by a Fickian mechanism, yielding orders of magnitude difference between the self-diffusional rates of the two molecules. This phenomenon might be further extended to alter the diffusional motion of molecules in nanoporous materials.}, number={9}, journal={JOURNAL OF CHEMICAL PHYSICS}, author={Chen, Qu and Moore, Joshua D. and Liu, Ying-Chun and Roussel, Thomas J. and Wang, Qi and Wu, Tao and Gubbins, Keith E.}, year={2010}, month={Sep} }
 @article{roussel_bichara_gubbins_pellenq_2009, title={Hydrogen storage enhanced in Li-doped carbon replica of zeolites: A possible route to achieve fuel cell demand}, volume={130}, ISSN={["0021-9606"]}, DOI={10.1063/1.3122382}, abstractNote={We first report the atomistic grand canonical Monte Carlo simulations of the synthesis of two realistic ordered microporous carbon replica in two siliceous forms of faujasite zeolite (cubic Y-FAU and hexagonal EMT). Atomistic simulations of hydrogen adsorption isotherms in these two carbon structures and their Li-doped composites were carried out to determine their storage capacities at 77 and 298 K. We found that these new forms of carbon solids and their Li-doped versions show very attractive hydrogen storage capacities at 77 and 298 K, respectively. However, for a filling pressure of 300 bars and at room temperature, bare carbons do not show advantageous performances compared to a classical gas cylinder despite of their crystalline micropore network. In comparison, Li-doped nanostructures provide reversible gravimetric and volumetric hydrogen storage capacities twice larger (3.75 wt % and 33.7 kg/m3). The extreme lattice stiffness of their skeleton will prevent them from collapsing under large external applied pressure, an interesting skill compared to bundle of carbon nanotubes, and metal organic frameworks (MOFs). These new ordered composites are thus very promising materials for hydrogen storage issues by contrast with MOFs.}, number={17}, journal={JOURNAL OF CHEMICAL PHYSICS}, author={Roussel, Thomas and Bichara, Christophe and Gubbins, Keith E. and Pellenq, Roland J. -M.}, year={2009}, month={May} }