Journal of the Korean Society of Visualization (한국가시화정보학회지)

The Korean Society of Visualization (한국가시화정보학회)
권호 표지
DOI QR코드

DOI QR Code

Electroconvective vortex on an Ion Exchange Membrane under Shear Flow

전단흐름 하에 이온교환막 위에서 발생하는 전기수력학적 와류

  • Kwak, Rhokyun (Department of Mechanical Engineering, Hanyang University)
  • Received : 2018.04.01
  • Accepted : 2018.04.25
  • Published : 2018.04.30
Download PDF
⟨ Previous Next ⟩

Abstract

Ion exchange membrane can transfer only cation or anion in electrically conductive fluids. Recent studies have revealed that such selective ion transport can initiate electroconvective instability, resulting vortical fluid motions on the membrane. This so-called electroconvective vortex (a.k.a. electroconvection (EC)) has been in the spotlight for enhancing an ion flux in electrochemical systems. However, EC under shear flow has not been investigated yet, although most related systems operate under pressure-driven flows. In this study, we present the direct visualization platform of EC under shear flow. On the transparent silicone rubber, microscale channels were fabricated between ion exchange membranes, while allowing microscopic visualization of fluid flow and ion concentration changes on the membranes. By using this platform, not only we visualize the existence of EC under shear flow, its unique characteristics are also identified: i) unidirectional vortex pattern, ii) its advection along the shear flow, and iii) shear-sheltering of EC vortices.

Keywords

References

  1. Xu, T. W., Ion exchange membranes: State of their development and perspective. J Membrane Sci 2005, 263(1-2), 1-29. https://doi.org/10.1016/j.memsci.2005.05.002
  2. Schoch, R. B.; Han, J.; Renaud, P., Transport phenomena in nanofluidics. Rev Mod Phys 2008, 80(3), 839-883. https://doi.org/10.1103/RevModPhys.80.839
  3. Probstein, R. F., Physicochemical Hydrodynamics: An Introduction. 2nd ed.; Wiley-Interscience: New York, 2003.
  4. Strathmann, H., Electrodialysis, a mature technology with a multitude of new applications. Desalination 2010, 264(3), 268-288. https://doi.org/10.1016/j.desal.2010.04.069
  5. Sonin, A. A.; Probstein, R. F., A hydrodynamic theory of desalination by electrodialysis. Desalination 1968, 5(3), 293-329. https://doi.org/10.1016/S0011-9164(00)80105-8
  6. Urtenov, M. K.; Uzdenova, A. M.; Kovalenko, A. V.; Nikonenko, V. V.; Pismenskaya, N. D.; Vasil'eva, V. I.; Sistat, P.; Pourcelly, G., Basic mathematical model of overlimiting transfer enhanced by electroconvection in flow-through electrodialysis membrane cells. J Membrane Sci 2013, 447, 190-202. https://doi.org/10.1016/j.memsci.2013.07.033
  7. Nikonenko, V. V.; Kovalenko, A. V.; Urtenov, M. K.; Pismenskaya, N. D.; Han, J.; Sistat, P.; Pourcelly, G., Desalination at overlimiting currents: State-of-the-art and perspectives. Desalination 2014, 342, 85-106. https://doi.org/10.1016/j.desal.2014.01.008
  8. Rubinstein, I.; Zaltzman, B., Electro-osmotically induced convection at a permselective membrane. Phys Rev E 2000, 62(2), 2238-2251. https://doi.org/10.1103/PhysRevE.62.2238
  9. Kim, S. J.; Wang, Y. C.; Lee, J. H.; Jang, H.; Han, J., Concentration polarization and nonlinear electrokinetic flow near a nanofluidic channel. Phys Rev Lett 2007, 99(4).
  10. Rubinstein, S. M.; Manukyan, G.; Staicu, A.; Rubinstein, I.; Zaltzman, B.; Lammertink, R. G. H.; Mugele, F.; Wessling, M., Direct Observation of a Nonequilibrium Electro-Osmotic Instability. Phys Rev Lett 2008, 101(23).
  11. Kwak, R.; Guan, G. F.; Peng, W. K.; Han, J. Y., Microscale electrodialysis: Concentration profiling and vortex visualization. Desalination 2013, 308, 138-146. https://doi.org/10.1016/j.desal.2012.07.017
  12. Kwak, R.; Pham, V. S.; Lim, K. M.; Han, J. Y., Shear Flow of an Electrically Charged Fluid by Ion Concentration Polarization: Scaling Laws for Electroconvective Vortices. Phys Rev Lett 2013, 110(11).
  13. Andersen, M. B.; van Soestbergen, M.; Mani, A.; Bruus, H.; Biesheuvel, P. M.; Bazant, M. Z., Current-Induced Membrane Discharge. Phys Rev Lett 2012, 109(10).
  14. Dydek, E. V.; Zaltzman, B.; Rubinstein, I.; Deng, D. S.; Mani, A.; Bazant, M. Z., Overlimiting Current in a Microchannel. Phys Rev Lett 2011, 107(11).
  15. Kwak, R.; Pham, V. S.; Kim, B.; Chen, L.; Han, J., Enhanced salt removal by unipolar ion conduction in ion concentration polarization desalination. Sci Rep-Uk 2016, 6(25349).
  16. Kwak, R.; Pham, V. S.; Han, J. Y., Sheltering the perturbed vortical layer of electroconvection under shear flow. J Fluid Mech 2017, 813, 799-823. https://doi.org/10.1017/jfm.2016.870
  17. Rubinstein, I.; Shtilman, L., Voltage against current curves of cation exchange membranes. J. Chem. Soc., Faraday Trans. 2 1979, 75, 231. https://doi.org/10.1039/f29797500231
  18. Dukhin, S. S.; Mishchuk, N. A., Intensification of Electrodialysis Based on Electroosmosis of the 2nd Kind. J Membrane Sci 1993, 79(2-3), 199-210. https://doi.org/10.1016/0376-7388(93)85116-E
  19. Mishchuk, N.; Gonzalez-Gaballero, F.; Takhistov, P., Electroosmosis of the second kind and current through curved interface. Colloid Surface A 2001, 181(1-3), 131-144. https://doi.org/10.1016/S0927-7757(00)00741-X
  20. Hunt, J. C. R.; Durbin, P. A., Perturbed vortical layers and shear sheltering. Fluid Dyn Res 1999, 24(6), 375-404. https://doi.org/10.1016/S0169-5983(99)00009-X
  21. Terry, P. W., Suppression of turbulence and transport by sheared flow. Rev Mod Phys 2000, 72(1), 109-165. https://doi.org/10.1103/RevModPhys.72.109
  22. Packard, N. H.; Crutchfield, J. P.; Farmer, J. D.; Shaw, R. S., Geometry from a Time-Series. Phys Rev Lett 1980, 45(9), 712-716. https://doi.org/10.1103/PhysRevLett.45.712