Entropy Scaling of ViscosityII: Predictive Scheme for Normal Alkanes

In
this work, a residual entropy value of 6/10 of the way between
the critical point and a value of −2/3 of Boltzmann constant
is shown to collapse the scaled viscosity for the family of normal
alkanes. Based on this approach, a nearly universal correlation is
proposed that can reproduce 95% of the experimental data for normal
alkanes within ±18% (without removal of clearly erroneous data).
This universal correlation has no new fluid-specific empirical parameters
and is based on experimentally accessible values. This collapse is
shown to be valid to a residual entropy half-way between the critical
point and the triple point, beyond which the macroscopically scaled
viscosity has a superexponential dependence on residual entropy, terminating
at the triple point. A key outcome of this study is a better understanding
of entropy scaling for fluids with intramolecular degrees of freedom.
A study of the transport and thermodynamic properties at the triple
point rounds out the analysis.