Structural and thermodynamic behavior of alkane chains at the liquid/vapor interface

Area of Science:

• Physical Chemistry
• Computational Fluid Dynamics

Background:

• Understanding molecular behavior at liquid-vapor interfaces is crucial for thermodynamics.
• Previous simulations of alkane fluids had limitations in accuracy and temperature range.

Purpose of the Study:

• To investigate the thermodynamics and structural behavior of alkane fluids at the liquid-vapor interface.
• To develop and validate a new computational model for fluid simulations.

Main Methods:

• Utilized computer simulations with three distinct molecular models.
• Analyzed fluid structure and molecular ordering near the melting point.
• Calculated interfacial tension and compared with experimental data.

Main Results:

• The newly proposed model showed improved agreement with experimental data compared to existing models.
• Molecules at the liquid-vapor interface exhibited greater order than those in the bulk liquid phase.
• Observed perpendicular alignment of some hydrocarbon chains at the interface.

Conclusions:

• The developed model accurately reproduces thermodynamic properties like interfacial tension.
• The study provides evidence for enhanced molecular ordering at the interface, consistent with experimental findings near the melting temperature.