Condensed Matter Physics, 1997, No 10, p. 51-60,
English
DOI:10.5488/CMP.10.51
Title: POLYMER PERCUS-YEVICK IDEAL CHAIN APPROXIMATION
FOR THE LENNARD-JONES CHAIN FLUID
Authors: Yu.V.Kalyuzhnyi (Institute for Condensed Matter Physics of
the Ukrainian
National Academy of Sciences, 1 Svientsitskii St., UA 290011 Lviv, Ukraine)
The structure and thermodynamic properties of the freely jointed
linear chain fluid with monomers interecting by the Lennard-Jones potential
are studied using the polymer Percus-Yevick (PPY) ideal chain approximation.
The theory is based on the Wertheim's multidensity integral-equation theory
for associating fluids, appropriately modified to describe the polymer fluids.
In the case of the chain system composed of 4, 8 and 16 monomeric
units the PPY ideal chain approximation is found to yield good agreement
with corresponding computer simulation results for the internal energy at
the entire range of the density and temperature studied.
For the longer chains composed of 50 and 100 segments the agreement becomes
slightly worse, especially at low values of the density. Predictions of the
theory for the structure properties are less satisfactory, i.e. theoretical
results for the intermolecular everage site-site distribution function of
16-mer fluid is only in semiquantitative agreement with Monte Carlo simulation
results. It is expected, that the thery will be more accurate in predicting
overall everage distribution functions and for the fluid of shorter chain
length.
Comments: Figs. 8, Refs. 14, Tabs. 0.