Vapor-Liquid Phase Equilibria for Linear and Branched Alkane Monolayers Physisorbed on Au(111)

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• 作者：Jeffrey J. Potoff and J. Ilja Siepmann
• 刊名：Langmuir
• 出版年：2002
• 出版时间：August 6, 2002
• 年：2002
• 卷：18
• 期：16
• 页码：6088 - 6095
• 全文大小：169K
• 年卷期：v.18,no.16(August 6, 2002)
• ISSN：1520-5827

文摘

Histogram-reweighting Monte Carlo simulations in the grand canonical ensemble were used to obtainvapor-liquid coexistence curves for a series of alkanes physisorbed on a flat gold substrate. The criticaltemperatures and densities of n-alkanes from methane to decane as well as the branched molecules2-methylpropane, 2,2-dimethylbutane, and 2,3-dimethylbutane were determined through a mixed-fieldanalysis. The ratio of the 2D (two-dimensional) to the 3D (three-dimensional) critical temperature wasfound to depend weakly on the chain length for n-alkanes, decreasing from T_c^2D/T_c^3D = 0.38 for methaneto T_c^2D/T_c^3D = 0.31 for n-decane. In contrast to typical bulk fluid behavior, the branched isomers were foundto have higher critical temperatures than their linear counterparts.