Molecular dynamics study of butane and hexane in silicalite

Journal Article · Thu Feb 06 04:00:00 EST 1992 · Journal of Physical Chemistry

DOI:https://doi.org/10.1021/j100182a009· OSTI ID:381786

June, R L; Bell, A T; Theodorou, D N ^[1]

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1. Univ. of California, Berkeley, CA (United States)

Molecular dynamics simulations are performed for n-butane and n-hexane in the zeolite silicalite over a range of sorbate loadings at 300 K. The simulations show that the molecular conformation of butane is sensitive to its local environment, while hexane is found to remain in a relatively linear conformation at all times. Furthermore, the molecules are found to reside in the two channel segments with 95% or greater probability while avoiding the channel intersection region. The rate of isomerization between conformers is largely independent of position within the zeolite pore structure. Diffusivities of the sorbate molecules are computed to be monotonically decreasing functions of sorbate loading. The computed self-diffusivities are near the largest experimental values, which scatter over many orders of magnitude. The long time constants governing the decay of orientational correlation functions in the hexane system suggest the need for simulations in excess of 1000 ps to properly probe the long time dynamics of the sorbate molecules. 47 refs., 7 figs., 9 tabs.

• Sponsoring Organization: USDOE
• OSTI ID: 381786
• Journal Information: Journal of Physical Chemistry, Journal Name: Journal of Physical Chemistry Journal Issue: 3 Vol. 96; ISSN JPCHAX; ISSN 0022-3654
• Country of Publication: United States
• Language: English

Related Subjects

40 CHEMISTRY
ADSORPTION
BUTANE
HEXANE
ISOMERIZATION
SORPTIVE PROPERTIES
ZEOLITES