Title: TOWARDS A SIMPLIFIED APPROACH TO THE MODELLING OF THE STAR-LIKE MOLECULE FLUIDS
Author(s): Yu.Duda (Programa de Ingenieria Molecular, Instituto Mexicano del Petr\'oleo, Eje Central L.Cardenas 152, 07730, M\'exico D.F.; Institute for Condensed Matter Physics of the National Academy of Sciences of Ukraine, 1 Svientsitskii Str., 79011 Lviv, Ukraine), A.Trokhymchuk (Institute for Condensed Matter Physics of the National Academy of Sciences of Ukraine, 1 Svientsitskii Str., 79011 Lviv, Ukraine; Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT 84602, USA)

A theoretical approach to considering a wide spectrum of equilibrium properties of fluids formed from the four-branched molecules (e.g. four-arm star polysterene samples, four-arm block copolymers, etc.) is presented and discussed. The proposed approach is within the framework of an associative version of integral equation theory and is based on an analytical solution of the four-site associative hard-sphere model. Results and discussion are explained by the comparison against Monte Carlo computer simulation data generated for a freely-joined tangent hard-sphere model of a star-like molecule fluid. It is shown that the proposed theory works well for the star-like molecule fluids in homogeneous phase where it predicts the structure for molecules with relatively long arms and at high densities. The obtained results qualitatively reproduce the most important experimental features of the solvation force induced between two macrosurfaces due to the presence of star-like aggregates.

Key words: star-like molecules, associative integral equation theory, computer simulation
PACS: 05.20.Jj, 61.25.Em