Advertisement

Role of viscoelastic interfaces in emulsion rheology and drop deformation

  • Philipp ErniEmail author
  • Peter Fischer
  • Erich J. Windhab
Article

Abstract

The small-deformation behavior of single Newtonian oil drops covered by an adsorbed viscoelastic protein layer and suspended in a Newtonian protein-free matrix phase was investigated in simple shear flow. A simple but effective technique is presented to coat the drops with a layer of surface-active protein (lysozyme), which was adsorbed irreversibly to the oil/water interface. The adsorption and network formation at the interface are tracked by interfacial shear and dilatational rheometry using a biconical disk interfacial rheometer and pendant drop tensiometry. While the clean drop is deforming to the expected ellipsoidal shape in shear flow according to the Taylor theory, the protein-covered drop is able to resist the bulk shear stress to a much higher degree. We propose that this effect is due to the adsorbed protein, which is known to form strong, gel-like viscoelastic networks when adsorbed at oil/water interfaces.

Key words

interfacial gels globular proteins interfacial rheology drop deformation emulsions 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. [1]
    EDWARDS D A, BRENNER H, WASAN D T. Interfacial transport processes and rheology [M]. Butterworth-Heinemann, Stonheam MA, 1991.Google Scholar
  2. [2]
    FULLER G G. Rheology of mobile intefaces [C]//BENDING D M, WALTERS K. Rheology Reviews [M]. Aberystwyth: The British Society of Rheology, 2003: 77–124.Google Scholar
  3. [3]
    PALIERNE J P. Linear rheology of emulsions with interfacial tension [J]. Rheologica Acta, 1990, 29: 204–214.CrossRefGoogle Scholar
  4. [4]
    van HEMELRIJCK E, van PUYVELDE P, VELANKAR S, et al. Interfacial elasticity and coalescence suppression in compatibilized polymer blends [J]. Journal of Rheology, 2004, 48: 143–158.CrossRefGoogle Scholar
  5. [5]
    JACOBS U, FAHRLANDER M, WINTERHALTER J, et al. Analysis of palierne’s emulsion model in the case of viscoelastic interfacial properties [J]. Journal of Rheology, 1999, 43: 1495–1509.CrossRefGoogle Scholar
  6. [6]
    OLDROYD J G. The effect of interfacial stabilizing films on the elastic and viscous properties of emulsions [C]//Proceedings of the Royal Society of London A, 1955, 232: 567–577.CrossRefGoogle Scholar
  7. [7]
    WILLIAMS A, JANSSEN J J, PRINS A. Behaviour of droplets in simple shear flow in the presence of a protein emulsifier [J]. Colloids and Surfaces A, 1997, 125: 189–200.CrossRefGoogle Scholar
  8. [8]
    TAYLOR G I. The formation of emulsions in definable fields of flow [C]//Proceedings of the Royal Society of London A, 1934, 146: 501–523.CrossRefGoogle Scholar
  9. [9]
    STONE H A. Dynamics of drop deformation and breakup in viscous fluids [J]. Annual Review of Fluid Mechanics, 1994, 26: 65–102.MathSciNetCrossRefGoogle Scholar
  10. [10]
    FLUMERFELT R W. Effects of dynamic interfacial properties on drop deformation and orientation in shear and extensional flow fields [J]. Journal of Colloid and Interface Science, 1980, 76: 330–349.CrossRefGoogle Scholar
  11. [11]
    PHILLIPS W J, GRAVES R W, FLUMERFELT R W. Experimental studies of drop dynamics in shear fields-role of dynamic interfacial effects [J]. Journal of Colloid and Interface Science, 1980, 76: 350–370.CrossRefGoogle Scholar
  12. [12]
    BARTHES-BIESEL D, DIAZ A, DHENIN E. Effect of constitutive laws for two-dimensional membranes on flow-induced capsule deformation [J]. Journal of Fluid Mechanics, 2002, 460: 211–222.CrossRefGoogle Scholar
  13. [13]
    CHANG K S, OLBRICHT W J. Experimental studies of the deformation and breakup of a synthetic capsule in steady and unsteady simple shear-flow [J]. Journal of Fluid Mechanics, 1993, 250: 609–633.CrossRefGoogle Scholar
  14. [14]
    BARTHES-BIESEL D, SGAIER H. Role of membrane viscosity on the orientation and deformation of a spherical capsule suspended in shear flow [J]. Journal of Fluid Mechanics, 1985, 160: 119–135.MathSciNetCrossRefGoogle Scholar
  15. [15]
    ERNI P, FISCHER P, WINDHAB E J, et al. Stress- and strain-controlled measurements of interfacial shear viscosity and viscoelasticity at liquid/liquid and gas/liquid interfaces [J]. Review of Scientific Instruments, 2003, 74: 4916–4924.CrossRefGoogle Scholar
  16. [16]
    OH S G, SLATTERY J C. Disk and biconical interfacial rheometers [J]. Journal of Colloid and Interface Science, 1978, 67: 516–525.CrossRefGoogle Scholar
  17. [17]
    SCRIVEN L E. Dynamics of a fluid interface: Equation of motion for newtonian surface fluids [J]. Chemical Engineering Science, 1960, 12: 98–108.CrossRefGoogle Scholar
  18. [18]
    GUNDE R, KUMAR A, LEHNERT-BATAR S, et al. Measurement of the surface and interfacial tension from maximum volume of a pendant drop [J]. Journal of Colloid and Interface Science, 2001, 244: 113–122.CrossRefGoogle Scholar
  19. [19]
    FREER E M, YIM K S, FULLER G G, et al. Interfacial rheology of globular and flexible proteins at the hexadecane/water interface: Comparison of shear and dilatational deformation [J]. Journal of Physical Chemistry B, 2004, 108: 3835–3844.CrossRefGoogle Scholar

Copyright information

© Central South University Press, Sole distributor outside Mainland China: Springer 2007

Authors and Affiliations

  • Philipp Erni
    • 1
    Email author
  • Peter Fischer
    • 1
  • Erich J. Windhab
    • 1
  1. 1.Laboratory of Food Process Engineering, ETH-Swiss FederalInstitute of TechnologyZurichSwitzerland

Personalised recommendations