Transport of Analytes under Mixed Electroosmotic and Pressure Driven Flow of Power Law Fluid

In this study, we have analyzed the transport of analytes
under a two dimensional steady incompressible flow of power-law
fluids through rectangular nanochannel. A mathematical model
based on the Cauchy momentum-Nernst-Planck-Poisson equations is
considered to study the combined effect of mixed electroosmotic
(EO) and pressure driven (PD) flow. The coupled governing
equations are solved numerically by finite volume method. We
have studied extensively the effect of key parameters, e.g., flow
behavior index, concentration of the electrolyte, surface potential,
imposed pressure gradient and imposed electric field strength on
the net average flow across the channel. In addition to study
the effect of mixed EOF and PD on the analyte distribution
across the channel, we consider a nonlinear model based on
general convective-diffusion-electromigration equation. We have also
presented the retention factor for various values of electrolyte
concentration and flow behavior index.




References:
[1] R. J. Hunter, Foundations of colloid science, Oxford University Press,
2001.
[2] R. F. Probstein, Physicochemical hydrodynamics, Wiley, 1994.
[3] J. H. Masliyah, S. Bhattacharjee, Electrokinetic and colloid transport
phenomena, John Wiley & Sons, 2006.
[4] H. A. Stone, A. D. Stroock, A. Ajdari, Engineering flows in small
devices: microfluidics toward a lab-on-a-chip, Annu. Rev. Fluid Mech.
36 (2004) 381–411.
[5] X. Wang, C. Cheng, S. Wang, S. Liu, Electroosmotic pumps and their
applications in microfluidic systems, Microfluidics and Nanofluidics
6 (2) (2009) 145–162.
[6] F. Kamis¸li, Flow analysis of a power-law fluid confined in an
extrusion die, International journal of engineering science 41 (10) (2003)
1059–1083.
[7] W. Zimmerman, J. Rees, T. Craven, Rheometry of non-newtonian
electrokinetic flow in a microchannel t-junction, Microfluidics and
Nanofluidics 2 (6) (2006) 481–492.
[8] M. Das, V. Jain, P. Ghoshdastidar, Fluid flow analysis of
magnetorheological abrasive flow finishing (mraff) process, International
Journal of Machine Tools and Manufacture 48 (3) (2008) 415–426.
[9] Y. Koh, N. Ong, X. Chen, Y. Lam, J. Chai, Effect of temperature
and inlet velocity on the flow of a nonnewtonian fluid, International
communications in heat and mass transfer 31 (7) (2004) 1005–1013.
[10] A. Y. Malkin, Rheology Fundamentals, ChemTec, 1994.
[11] S. Das, S. Chakraborty, Analytical solutions for velocity, temperature
and concentration distribution in electroosmotic microchannel flows of a
non-Newtonian bio-fluid, Analytica Chimica Acta 559 (1) (2006) 15–24.
[12] C. Zhao, E. Zholkovskij, J. H. Masliyah, C. Yang, Analysis of
electroosmotic flow of power-law fluids in a slit microchannel, Journal
of colloid and interface science 326 (2) (2008) 503–510.
[13] C. Rice, R. Whitehead, Electrokinetic flow in a narrow cylindrical
capillary, The Journal of Physical Chemistry 69 (11) (1965) 4017–4024.
[14] G. Tang, X. Li, Y. He, W. Tao, Electroosmotic flow of non-Newtonian
fluid in microchannels, Journal of Non-Newtonian Fluid Mechanics
157 (1) (2009) 133–137.
[15] N. Vasu, S. De, Electroosmotic flow of power-law fluids at high zeta
potentials, Colloids and Surfaces A: Physicochemical and Engineering
Aspects 368 (1) (2010) 44–52.
[16] A. Babaie, A. Sadeghi, M. H. Saidi, Combined electroosmotically and
pressure driven flow of power-law fluids in a slit microchannel, Journal
of Non-Newtonian Fluid Mechanics 166 (14) (2011) 792–798.
[17] S. Pennathur, J. G. Santiago, Electrokinetic transport in nanochannels.
1. theory, Analytical chemistry 77 (21) (2005) 6772–6781.
[18] S. K. Griffiths, R. H. Nilson, Electroosmotic fluid motion and late-time
solute transport for large zeta potentials, Analytical chemistry 72 (20)
(2000) 4767–4777.
[19] X. Xuan, D. Li, Solute separation in nanofluidic channels:
Pressure-driven or electric field-driven?, Electrophoresis 28 (4) (2007)
627–634.
[20] C. A. Fletcher, Computational techniques for fluid dynamics vol 2, 2nd
edn, Springer, Berlin, 1991.
[21] S. Patankar, Numerical heat transfer and fluid flow, CRC Press, 1980.
[22] D. Gillespie, S. Pennathur, Separation of ions in nanofluidic channels
with combined pressure-driven and electro-osmotic flow, Analytical
chemistry 85 (5) (2013) 2991–2998.