RESEARCH PAPER Slippage of binary fluid mixtures in a nanopore Djilali Ameur • Guillaume Gallie ´ro Received: 24 August 2012 / Accepted: 15 January 2013 / Published online: 31 January 2013 Ó Springer-Verlag Berlin Heidelberg 2013 Abstract This work focuses on the slip phenomenon at the fluid–solid interface accompanying Poiseuille flow of simple binary miscible fluids in a slit nanopore. To explore such flows, molecular dynamics simulations are used on Lennard–Jones binary mixtures composed of species of varying affinities with the walls. The results have shown that the apparent slip magnitude at the fluid–solid interface depends largely on the species that is dominant in contact with the walls. In addition, it has been shown that the velocity profiles of each species (of different ‘‘wettability’’) does not superpose with the velocity profile of the mixture and such a result points out the limitations of the classical approaches based on a single momentum conservation equation to deal with mixtures flow in nanochannels. Keywords Molecular dynamics  Nanopore  Slip boundary conditions  Mixtures 1 Introduction The main objective of this work is to improve the under- standing of the fluid flows of mixtures confined in low permeability porous media (nano-channels), as such systems are of increasing academic and industrial interests (Bear 1988; Karniadakis and Beskok 2002; Kerkhof and Geboers 2005; Montel et al. 2007). However, many studies (Barrat and Bocquet 1999; Sokhan et al. 2002; Tretheway and Meinhart 2002; Khare et al. 2006; Ameur et al. 2008; Ameur 2008) in micro and nano-scale channels have shown the appearance of some peculiar phenomena like slipping flow near the wall. This indicates that the modeling of a fluid flow close to an interface at the nano-scale with the assumption of no-slip at the wall is often inaccurate (Granick et al. 2003; Bocquet and Barrat 2007). Rather surprisingly, while the modeling problem of the slippage for pure and low-density fluids in micro and nano-fluidic devices has received large attention, few studies have been dedicated to the slippage in multicomponent fluids out of the dilute situation (Denniston and Robbins 2001, 2006; Kerkhof and Geboers 2005; Kim et al. 2009; Hsu and Patankar 2010). Thus, in this work, we have studied the flow behavior of pure fluids and mixtures confined in a nano-channel and then tried to describe the results using a simple empirical scheme. The slippage phenomenon in micro and nano-scale channels can be influenced by various physical factors, such as fluid and solid species, surface roughness, wetta- bility, temperature, pressure, fluid viscosity…. The wetta- bility in porous media has long been a subject of interest (Barrat and Bocquet 1999; Kim et al. 2008; Huang et al. 2008) which has been revived by a number of experiments (Tretheway and Meinhart 2002). However, it still remains difficult to evaluate quantitatively the relationship between the wettability and the slip phenomenon in the multicom- ponent fluid case. The difficulty is not limited only to the characterization of the slip effects which depends of sev- eral geometric and thermodynamic factors, but also of the possibility that the different compounds in multicomponent D. Ameur M2P2, Universite ´ Paul-Ce ´zanne, Aix-Marseille III, I.M.T. Technopo ˆle de Cha ˆteau-Gombert, 38 rue Fre ´de ´ric Joliot-Curie, 13451 Marseille Cedex 20, France D. Ameur (&)  G. Gallie ´ro LFC-R, Universite ´ de Pau et des Pays de l’Adour, Centre Universitaire de recherche Scientifique, BP 1155, 64013 Pau Cedex, France e-mail: d.ameur@yahoo.fr G. Gallie ´ro e-mail: guillaume.galliero@univ-pau.fr 123 Microfluid Nanofluid (2013) 15:183–189 DOI 10.1007/s10404-013-1141-9