A globally accurate theory for a class of binary mixture models.pdf

1 0 0 2 A globally accurate theory for a class of binary v o mixture models N 1 1 Adriana G. Dickmana and G. Stellb ] h a c Departamento de F´ısica e Qu´ımica, Pontif´ıcia Universidade Cat´olica de Minas Gerais, e m Av. Dom Jos´e Gaspar, 500, Cora¸c˜ao Eucar´ıstico, 30535-610, Belo Horizonte - MG, Brasil - t b a Department of Chemistry, State University of New York at Stony Brook, Stony Brook, t s t. New York 11794-3400, U.S.A. a m- February 1, 2008 d n o c Abstract [ Using the self-consistent Ornstein-Zernike approximation (SCOZA) results 1 v for the 3D Ising model, we obtain phase diagrams for binary mixtures described 7 0 by decorated models. We obtain the plait point, binodals, and closed-loop coex- 2 istence curves for the models proposed by Widom, Clark, Neece, and Wheeler. 1 1 The results are in good agreement with series expansions and experiments. 1 0 / t a m - d n o c : aelectronic address: adickman@pucminas.br v i phone number: 55-31-3319-4176 X r belectronic address: gstell@mail.chem.sunysb.edu a phone number: +1-631-632-7898 fax number: +1-631-632-7960 1 1. Introduction Critical phenomena of mixtures are considerably more complicated to inves- tigate than such phenomena in pure fluids. Purification of components, precise de- termination of composition, gravitational effects and long equil