Viscosity of liquid mixtures: the Vesovic-Wakeham method for chain molecules.

New expressions for the viscosity of liquid mixtures, consisting of chain-like molecules, are derived by means of Enskog-type analysis. The molecules of the fluid are modelled as chains of equally sized, tangentially joined, and rigid spheres. It is assumed that the collision dynamics in such a fluid can be approximated by instantaneous collisions. We determine the molecular size parameters from the viscosity of each pure species and show how the different effective parameters can be evaluated by extending the Vesovic-Wakeham (VW) method. We propose and implement a number of thermodynamically consistent mixing rules, taking advantage of SAFT-type analysis, in order to develop the VW method for chain molecules. The predictions of the VW-chain model have been compared in the first instance with experimental viscosity data for octane-dodecane and methane-decane mixtures, thus, illustrating that the resulting VW-chain model is capable of accurately representing the viscosity of real liquid mixtures.

[1]  G. Jackson,et al.  An analytical equation of state for chain molecules formed from Yukawa segments , 1999 .

[2]  W. Wakeham,et al.  Predicting the viscosity of liquid refrigerant blends: comparison with experimental data , 2005 .

[3]  G. Jackson,et al.  A kinetic theory description of the viscosity of dense fluids consisting of chain molecules. , 2008, The Journal of chemical physics.

[4]  W. Wakeham,et al.  Prediction of the viscosity of dense fluid mixtures , 2003 .

[5]  George Jackson,et al.  SAFT: Equation-of-state solution model for associating fluids , 1989 .

[6]  J. H. Dymond,et al.  Hard-sphere theories of transport properties , 1985 .

[7]  H. Tsai,et al.  Prediction of the transport properties of a polyatomic gas , 2010 .

[8]  Philippe Ungerer,et al.  Molecular simulation of the thermophysical properties of fluids: From understanding toward quantitative predictions , 2007 .

[9]  H. Xiang,et al.  Viscosity correlations for minor constituent fluids in natural gas: n-octane, n-nonane and n-decane , 2004 .

[10]  S. Sandler,et al.  On the viscosity and thermal conductivity of dense gases , 1979 .

[11]  George Jackson,et al.  New reference equation of state for associating liquids , 1990 .

[12]  K. E. Starling,et al.  Equation of State for Nonattracting Rigid Spheres , 1969 .

[13]  George Jackson,et al.  Phase equilibria of associating fluids , 2006 .

[14]  M. Wertheim.  Fluids of dimerizing hard spheres, and fluid mixtures of hard spheres and dispheres , 1986 .

[15]  Y. Chiew,et al.  Percus-Yevick integral-equation theory for athermal hard-sphere chains , 1991 .

[16]  G. Gao,et al.  Lennard–Jones Chain Model for Self-Diffusion of n-Alkanes , 2000 .

[17]  G. Gao,et al.  Self-diffusion coefficient equation for polyatomic fluid , 1999 .

[18]  B. Alder,et al.  Studies in Molecular Dynamics. VIII. The Transport Coefficients for a Hard-Sphere Fluid , 1970 .

[19]  J. Kirkwood.  Statistical Mechanics of Fluid Mixtures , 1935 .

[20]  George Jackson,et al.  THE THERMODYNAMICS OF MIXTURES AND THE CORRESPONDING MIXING RULES IN THE SAFT-VR APPROACH FOR POTENTIALS OF VARIABLE RANGE , 1998 .

[21]  V. Vesovic,et al.  Calculation of the transport and relaxation properties of dilute water vapor. , 2009, The Journal of chemical physics.

[22]  George Jackson,et al.  Mixtures of associating spherical and chain molecules , 1989 .

[23]  R. Laghaei,et al.  Statistical-mechanical theory of rheology: Lennard-Jones fluids. , 2005, The Journal of chemical physics.

[24]  V. Vesovic,et al.  Calculation of the transport properties of carbon dioxide. II. Thermal conductivity and thermomagnetic effects. , 2004, The Journal of chemical physics.

[25]  K. Gubbins,et al.  Phase equilibria of associating fluids : spherical molecules with multiple bonding sites , 1988 .

[26]  M. Wertheim,et al.  Fluids with highly directional attractive forces. III. Multiple attraction sites , 1986 .

[27]  K. E. Starling,et al.  Equilibrium Thermodynamic Properties of the Mixture of Hard Spheres , 1971 .

[28]  F. Montel,et al.  Molecular dynamics comparative study of Lennard-Jones -6 and exponential -6 potentials: application to real simple fluids (viscosity and pressure). , 2006, Physical review. E, Statistical, nonlinear, and soft matter physics.

[29]  C. Boned,et al.  Molecular dynamics study of the repulsive form influence of the interaction potential on structural, thermodynamic, interfacial, and transport properties. , 2008, The Journal of chemical physics.

[30]  George Jackson,et al.  Statistical associating fluid theory for chain molecules with attractive potentials of variable range , 1997 .

[31]  M. M. Piñeiro,et al.  Simultaneous estimation of phase behavior and second-derivative properties using the statistical associating fluid theory with variable range approach. , 2006, The Journal of chemical physics.

[32]  E. A. Mason,et al.  Composition dependence of the viscosity of dense gas mixtures , 1977 .

[33]  B. Eu,et al.  Generic van der Waals equation of state, modified free volume theory of diffusion, and viscosity of simple liquids. , 2005, The journal of physical chemistry. B.

[34]  Marcia L. Huber,et al.  Transport properties of n-dodecane , 2004 .

[35]  Tomáš Boublı́k,et al.  Hard‐Sphere Equation of State , 1970 .

[36]  V. Vesovic,et al.  Calculation of the transport properties of carbon dioxide. I. Shear viscosity, viscomagnetic effects, and self-diffusion , 2002 .

[37]  V. Vesovic,et al.  Calculation of the transport and relaxation properties of methane. I. Shear viscosity, viscomagnetic effects, and self-diffusion. , 2008, The Journal of chemical physics.

[38]  A. Ben-Naim.  Statistical Mechanical Study of Hydrophobic Interaction. I. Interaction between Two Identical Nonpolar Solute Particles , 1971 .

[39]  George Jackson,et al.  Study of the demixing transition in model athermal mixtures of colloids and flexible self-excluding polymers using the thermodynamic perturbation theory of Wertheim , 2003 .

[40]  G. Gao,et al.  Study on self-diffusion in water, alcohols and hydrogen fluoride by the statistical associating fluid theory , 2001 .

[41]  L. Onsager.  THE EFFECTS OF SHAPE ON THE INTERACTION OF COLLOIDAL PARTICLES , 1949 .

[42]  A. Pádua,et al.  Viscosity and density of mixtures of methane and n-decane from 298 to 393 K and up to 75 MPa , 2004 .

[43]  G. Jackson,et al.  The theoretical prediction of the cricital points of alkanes, perfluoroalkanes, and their mixtures using bonded hard-sphere (BHS) theory , 1996 .

[44]  William A. Wakeham,et al.  Prediction of the viscosity of fluid mixtures over wide ranges of temperature and pressure , 1989 .

[45]  M. Wertheim,et al.  Fluids with highly directional attractive forces. IV. Equilibrium polymerization , 1986 .

[46]  G. Jackson,et al.  Describing the Properties of Chains of Segments Interacting Via Soft-Core Potentials of Variable Range with the SAFT-VR Approach , 1998 .

[47]  C. Boned,et al.  Molecular Dynamics Study of the Lennard-Jones Fluid Viscosity: Application to Real Fluids , 2005 .

[48]  V. Vesovic,et al.  Calculation of the transport and relaxation properties of methane. II. Thermal conductivity, thermomagnetic effects, volume viscosity, and nuclear-spin relaxation. , 2009, The Journal of chemical physics.