Abstract
Histogram-reweighting Monte Carlo simulations in the grand canonical ensemble were used to obtain vapor-liquid coexistence curves for a series of alkanes physisorbed on a flat gold substrate. The critical temperatures and densities of n-alkanes from methane to decane as well as the branched molecules 2-methylpropane, 2,2-dimethylbutane, and 2,3-dimethylbutane were determined through a mixed-field analysis. The ratio of the 2D (two-dimensional) to the 3D (three-dimensional) critical temperature was found to depend weakly on the chain length for n-alkanes, decreasing from Tc2D/Tc3D = 0.38 for methane to Tc2D/Tc3D= 0.31 for n-decane. In contrast to typical bulk fluid behavior, the branched isomers were found to have higher critical temperatures than their linear counterparts.
Original language | English (US) |
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Pages (from-to) | 6088-6095 |
Number of pages | 8 |
Journal | Langmuir |
Volume | 18 |
Issue number | 16 |
DOIs | |
State | Published - Aug 6 2002 |