Effect of nonionic surfactants on the electrorheology of emulsions

  • Ha, Jong-Wook (Department of Chemical Engineering Korea Advanced Institute of Science and Technology) ;
  • Moon, Jung-Hyuk (Department of Chemical Engineering Korea Advanced Institute of Science and Technology) ;
  • Yang, Seung-Man (Department of Chemical Engineering Korea Advanced Institute of Science and Technology)
  • Published : 1999.09.01

Abstract

In this study, we consider the effect of nonionic surfactants on the rheological responses of emulsion systems under the action of a uniform do electric field. The model emulsions consist of a less conducting dispersed phase and a more conducting continuous phase. When the shear flow is weak, the positive viscosity effect is produced due to the formation of chain-like morphology. The nonionic surfactants used here generate two distinctively different effects. Specifically, first, the steric hindrance induced by the surfactant molecules renders the structure unstable, and thereby reduces the degree of positive viscosity effect. Secondly, the presence of surfactant molecules also prevents the rotation of the dispersed droplets by anchoring across the interface or by decreasing the size of dispersed phase. The second effect suppresses the negative viscosity effect.

Keywords

References

  1. J. Phys. D Appl. Phys. v.21 Electro-rheology Block, H;J.P. Kelly
  2. Phys. Fluids v.6 Negative ciscosity of ferrofluid under alternating magnetic field Shliomis, M.I.;K.I. Morozov
  3. Phys. Rev. Lett. v.75 Nagatice-viscosity effect in a magnetic fluid Bacri, J.C.;R. Perzynski;M.I. Shliomis;G. I. Burde
  4. Interfacial Transport Processes and Rheology Edwards, D. A.;H. Brenner;D. T. Wasan
  5. J. Rheol. Rheological responses of oil-in-oilemulsions in an electric field Ha, J.W.;S.M.Yang
  6. J. Colloid Interface Sci. v.175 Effects of surfactant on the deformation and stability of a viscous fluid an electric field Ha, J.W.;S.M.Yang
  7. J. Colloid Interface Sci. v.206 Effect of nonionic surfactant on the deformation and breakup of a drop in an electric field Ha, J.W.;S.M. Yang
  8. J. Non-Newtonian Fluid Mech. v.76 Positive and 'negative' electro-rheoligical effect of liqued blends Kimura, H.;K.Aikawa;Y. Masubuchi;J. Takimoto;K. Koyama;T. Uemura
  9. J. Fluid Mech. v.341 The effect of surfactants of drop deformation and on the rheology of dilute emulsions in Stokes flow Li, X. F.;C. Pozrikidis
  10. J. Rheol. v.43 Electrorheological properties of a type-I immiscible polymer blend: Scaling and structural changes Orihara, H.;Y.Hosoi;K. Tajiri;Y. Ishivashi;M. Doi;A. Inoue
  11. J. Rheol. v.33 Viscosity concentration relationships for emulsions Pal, R.;W.Rhodes
  12. Colloids and Surfaces v.64 Rheological behavior of Concentrated surfactant solutions and emulsions Pals, R.
  13. J. Colloi Interface Sci. v.195 Characteristics of electrorheological responses in an emulsion system Pan, X.D.;G.H. McKinley
  14. Phys. Fluids v.8 Marangoni effects on drop deformation in an extensional flow: The role of surfactant physical chemistry. I. Insoluble surfactants Pawar, Y.;K.J. Stebe
  15. Ferrohydrodynamics Rosensweig, R. E.
  16. Science v.271 Negative viscosity in a magnetic fluid Rosensweig, R. E.
  17. J. Rheol. v.41 Electrorhological effect in immiscible polymer blends Tajiri, K.;K. Ohta;T. Nagaya;H. Orihara;Y. Ishibashi;M. Doi;A. Inoue
  18. J. Rheol. v.42 Transient response of electrorheological effect to a step field in an immiscible polymer blend: First mode in type I blend Tajiri, K.;H. Orihara;Y. Ishibashi;M. Doi;A. Inoue
  19. J. Rheol. v.43 Transient response of electrorheological effect to a step field in an immiscible polymer blend: Second mode in type I blend Tajiri, K.;H. Orkhara;Y. Ishibashi;M. Doi;A. Inoue
  20. J. Rheol. v.41 Negative electrorheological effect and electrical properties of a Teflon/silicone oil suspension Wu, C. W.;H. Conrad
  21. Phys. Rev. E v.58 Experiments on negative and positive magnetoviscosity in an alternating magnetic field Zeuner, A.;R. RichterlI. Rehberg
  22. Abby, Rev, Mater. Sci. v.23 Material properties and the electrorheological response Zukoski, C. F.