Determination of the distance-dependent viscosity of mixtures in parallel slabs using non-equilibrium molecular dynamics

• Published in: Physical chemistry chemical physics : PCCP Vol. 14; no. 1; pp. 364 - 365
• Main Authors: Paez, Stanislav, Pedota, Milan
• Format: Journal Article
• Language: English
• Published: Cambridge Royal Society of Chemistry 14.03.2012
• Subjects: Chemistry; Exact sciences and technology; General and physical chemistry; Hydrogen bonding; Methanol - chemistry; Methyl alcohol; Molecular dynamics; Molecular Dynamics Simulation; Shear viscosity; Slabs; Surface physical chemistry; Surface Properties; Titanium - chemistry; Titanium dioxide; Viscosity; Walls; Water - chemistry; Water; Viscosity; Binary compound; Experimental data; Computer simulation; Force; Rutile; Transition element compounds; Molecular dynamics; Alcohol; Equilibrium; Velocity; Shear viscosity; Poiseuille flow; Alkanol; Titanium oxide; Interface; Rheological properties; Surface flow; Hydrogen bond; Methanol
• ISSN: 1463-9076; 1463-9084; 1463-9084
• DOI: 10.1039/c2cp22136e

We generalize a technique for determination of the shear viscosity of mixtures in planar slabs using non-equilibrium computer simulations by applying an external force parallel to the surface generating Poiseuille flow. The distance-dependent viscosity of the mixture, given as a function of the distance from the surface, is determined by analysis of the resulting velocity profiles of all species. We present results for a highly non-ideal water + methanol mixture in the whole concentration range between rutile (TiO 2 ) walls. The bulk results are compared to the existing equilibrium molecular dynamics and experimental data while the inhomogeneous viscosity profiles at the interface are interpreted using the structural data and information on hydrogen bonding. A water + methanol mixture in a slab formed by rutile (TiO 2 ) surfaces. For viscosity determination, the liquid is subject to an external force along the surfaces, which generates Poiseuille flow.