TITLE:
Thermal Analysis of Thermophysical Data for Equilibrium Pure Fluids
AUTHORS:
Boris Sedunov
KEYWORDS:
Molecular Interaction; Cluster; Equilibrium Constant; Bond Energy; Structural Transition; Isotopic Effect
JOURNAL NAME:
Journal of Modern Physics,
Vol.4 No.7B,
July
15,
2013
ABSTRACT:
The thermal analysis of precise thermophysical data for pure fluids
from electronic databases is developed to investigate the molecular interaction
mechanisms and parameters and the structural features of heterogeneities in
fluids. The method is based on the series expansion of thermophysical values by
powers of the monomer fraction density. Unlike the virial expansion by powers
of the total density, the series expansion terms in this method directly
reflect properties of the corresponding cluster fractions. The internal energy
had been selected among thermophysical properties as the most informative for
this method. The thermal analysis of its series expansion coefficients permits
to estimate the temperature dependence of the pair bond parameters, the
clusters’ bond energies and equilibrium constants, the structural transitions
between dominating isomers of clusters. The application of method to different
pure fluids, including noble and molecular gases with van der Waals and polar
molecular interactions, brings unknown clusters’ characteristics for the
fluids under investigation. The thermal analysis of the ordinary and heavy
Water vapors points on no trivial isotopic effects. The unpredictable growth of
the pair bond energy with temperature in Alkanes points on existence in hydrocarbons
of some unknown molecular interaction forces in addition to dispersion forces.