Combined electroosmotically and pressure driven flow in soft nanofluidics

• Published in: Journal of colloid and interface science Vol. 460; pp. 361 - 369
• Main Authors: Matin, Meisam Habibi, Ohshima, Hiroyuki
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 15.12.2015
• Subjects: Cations; Electrolytes; Electroosmosis - methods; Electroosmotic flow; Hydrodynamics; Ions; Kinetics; Mathematics; Models, Theoretical; Nanostructures - chemistry; Nanotechnology - methods; PEL; Pressure; Rheology - methods; Slip; Soft nanochannel; Solutions; Static Electricity; Surface charge; Surface Properties; Electroosmotic flow; Surface charge; PEL; Soft nanochannel; Slip
• ISSN: 0021-9797; 1095-7103
• DOI: 10.1016/j.jcis.2015.08.070

[Display omitted] The present study is devoted to the analysis of mixed electroosmotic and pressure driven flows through a soft charged nanochannel considering boundary slip and constant charge density on the walls of the slit channel. The sources of the fluid flow are the pressure gradient along the channel axis and the electrokinetic effects that trigger an electroosmotic flow under the influence of a uniformly applied electric field. The polyelectrolyte layer (PEL) is denoted as a fixed charge layer (FCL) and the electrolyte ions can be present both inside and outside the PEL i.e., the PEL–electrolyte interface acts as a semi-penetrable membrane. The Poisson–Boltzmann equation is solved assuming the Debye–Hückel linearization for the low electric potential to provide us with analytical closed form solutions for the conservation equations. The conservation equations are solved to obtain the electric potential and velocity distributions in terms of governing dimensionless parameters. The results for the dimensionless electric potential, the dimensionless velocity and Poiseuille number are presented graphically and discussed in detail.