Using gamma distributions to predict self-diffusivities and density of states of fluids confined in carbon nanotubes.
The density of states of rare gas atoms confined in carbon nanotubes is analyzed using a recently proposed model based on gamma distributions [Krishnan and Ayappa, J. Chem. Phys., 124 144503 (2006)]. The inputs into the model are the 2nd and 4th frequency moments that are obtained from molecular dynamics simulations. The predicted density of states, velocity autocorrelation functions and self-diffusivities are compared with those obtained from molecular dynamics simulations, for different nanotube loadings and temperatures. All results are reported for argon confined in a (16,16) carbon nanotube. The model predictions are extremely accurate at intermediate reduced densities of rhosigma(3) = 0.3, 0.4, where the majority of the self-diffusivity predictions lie within 10% of the simulation results. Since the frequency moments can be also obtained from Monte Carlo simulations, the study suggests an alternate route to the system dynamics of strongly confined fluids.
Choudhary
Vinit
V
Department of Chemical Engineering, Indian Institute of Science, Bangalore 560012, India.
Ayappa
K G
KG
D001128:Argon / Q000737:chemistry*; D003198:Computer Simulation; D008956:Models, Chemical; D037742:Nanotubes, Carbon; D012996:Solutions; D013816:Thermodynamics
D037742:Nanotubes, Carbon; D012996:Solutions; D001128:Argon