Advertisement

Hard spheres versus Yukawa particles: Differences and similarities

  • G. Nägele
  • M. Watzlawek
  • R. Klein
Conference paper
Part of the Progress in Colloid & Polymer Science book series (PROGCOLLOID, volume 104)

Abstract

Whereas structural properties of suspensions of hard spheres of diameter σ are well approximated by analytic expressions, it is necessary to use numerical solutions of integral equations to calculate these properties when the pair potentials have a soft part. The finite range of repulsive pair potentials gives rise to a correlation hole, meaning that the pair correlation function g(r) is essentially equal to zero up to a well-defined nearestneighbour separation larger than σ. The aim of this work is to show that because of the correlation hole various dynamic properties of chargestabilized suspensions are qualitatively different from those of hard spheres. It will be argued that the observed non-linear volume fraction dependencies of the shorttime self-diffusion coefficients and of the sedimentation velocity can be understood in terms of a model of effective hard spheres with diameter σ EHS which depends on the volume fraction. Moreover, the long-ranged electrostatic repulsion gives rise to an unexpected enhancement of the longtime self-diffusion coefficient due to hydrodynamic interactions, in contrast to what is known for hard spheres. This enhancement is also understood in terms of an effective hard sphere model.

Key words

Self-diffusion collective diffusion hydrodynamic interactions charge stabilized suspensions effective hard spheres 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1.
    Pusey PN (1991) Colloidal suspensions In: Hansen J-P, Levesque D, Zinn-Justin J (eds) Liquids, Freezing and Glass Transition: II, North Holland, AmsterdamGoogle Scholar
  2. 2.
    Medina-Noyola M, McQuarrie DA (1980) J Chem Phys 73:6279CrossRefGoogle Scholar
  3. 3.
    Belloni L (1986) J Chem Phys 85:519CrossRefGoogle Scholar
  4. 4.
    Löwen H, Hansen JP, Madden PA, (1993) J Chem Phys 98:3275CrossRefGoogle Scholar
  5. 5.
    Nägele G (1996) Phys Rep 272:215CrossRefGoogle Scholar
  6. 6.
    Klein R, D'Aguanno B (1996) Staticscattering properties of colloidal suspensions, In: Brown W (ed) Light Scattering, Principles and Development. Clarendon Press, Oxford, pp 30–102Google Scholar
  7. 7.
    Nägele G, Steininger B, Genz U, Klein R (1994) Physica Scripta T 55:119CrossRefGoogle Scholar
  8. 8.
    Nägele G, Mandl B, Klein R (1995) Progr Colloid Polym Sci 98:117CrossRefGoogle Scholar
  9. 9.
    Thies-Weessie DME, Philipse AP, Nägele G, Mandl B, Klein R (1995) J Coll Int Sci 176:43CrossRefGoogle Scholar
  10. 10.
    Watzlawek M, Nägele G (1997) Physica A 235:56CrossRefGoogle Scholar
  11. 11.
    Watzlawek M, Nägele G, University of Konstanz, submittedGoogle Scholar
  12. 12.
    Nägele G, Baur P, University of Konstanz, Physica A, in pressGoogle Scholar
  13. 13.
    Hansen J-P, McDonald IR (1986) Theory of simple liquids. Academic Press, London, 2nd edGoogle Scholar
  14. 14.
    Nägele G, Medina-Noyola M, Klein R, Arauz-Lara JL (1988) Physica A 149:123CrossRefGoogle Scholar
  15. 15.
    Jones RB, Pusey PN (1991) Annu Rev Phys Chem 42:137CrossRefGoogle Scholar
  16. 16.
    Jones RB (1988) Physica A 150:339CrossRefGoogle Scholar
  17. 17.
    Happel J, Brenner H (1973) Low Reynolds Number Hydrodynamics. Noordhoff, LeidenGoogle Scholar
  18. 18.
    Felderhof BU (1977) Physica A 89:373CrossRefGoogle Scholar
  19. 19.
    Klein R, Nägele G (1994) II nouvo cimento 16 D:963CrossRefGoogle Scholar
  20. 20.
    Phalakornkul JK, Gast AP, Pecora R, Nägele G, Ferrante A, Mandl-Steininger B, Klein R (1996) Phys Rev E 54:661CrossRefGoogle Scholar
  21. 21.
    Philipse AP, Vrij A (1988) J Chem Phys 88:6459CrossRefGoogle Scholar
  22. 22.
    Genz U, Klein R (1991) Physica 171:26CrossRefGoogle Scholar
  23. 23.
    Nägele G, Kellerbauer O, Krause R, Klein R (1993) Phys Rev E 47:2562CrossRefGoogle Scholar
  24. 24.
    Beenakker CWJ, Mazur P (1983) Physica A 120:388CrossRefGoogle Scholar
  25. 25.
    Watzlawek M, Nägele G, this volumeGoogle Scholar
  26. 26.
    Batchelor GK (1972) J Fluid Mech 52:245CrossRefGoogle Scholar
  27. 27.
    Cichocki B, Felderhof BU (1989) Physica A 154:213CrossRefGoogle Scholar
  28. 28.
    Batchelor GK (1976) J Fluid Mech 74:1CrossRefGoogle Scholar
  29. 29.
    Cichocki B, Felderhof BU (1988) J Chem Phys 89:1049CrossRefGoogle Scholar
  30. 30.
    Degiorgio V, Piazza R, Bellini T (1994) Adv Coll Int Sci 48:61CrossRefGoogle Scholar
  31. 31.
    Degiorgio V, Piazza R, Jones RB (1995) Phys Rev E 52:2707CrossRefGoogle Scholar
  32. 32.
    Cichocki B, Felderhof BU (1991) J Chem Phys 94:556CrossRefGoogle Scholar
  33. 33.
    Denkov ND, Petsev DN (1992) Physica A 183:462CrossRefGoogle Scholar
  34. 34.
    Wertheim MS (1963) Phys Rev Lett 10:321CrossRefGoogle Scholar
  35. 35.
    Nägele G, University of Konstanz, unpublished resultsGoogle Scholar
  36. 36.
    Buscall R, Goodwin JW, Ottewill RH, Tadros TF (1982) J Coll Int Sci 85:78CrossRefGoogle Scholar
  37. 37.
    Kops-Werkhoven MM, Fijnaut HM (1981) J Chem Phys 74:1618CrossRefGoogle Scholar
  38. 38.
    Pusey PN, van Megen W (1983) J Phys 44:285Google Scholar
  39. 39.
    Ottewill RH, Williams NSJ (1987) Nature 325:232CrossRefGoogle Scholar
  40. 40.
    van Megen W, Underwood SM (1989) J Chem Phys 91:552CrossRefGoogle Scholar
  41. 41.
    van Veluwen A, Lekkerkerker HNW, de Kruif CG, Vrij A (1987) J Chem Phys 87:4873CrossRefGoogle Scholar
  42. 42.
    Ackerson BJ, Oklahoma State University, private communicationGoogle Scholar
  43. 43.
    Bitzer F, Palberg T, Leiderer P, University of Konstanz, private communicationGoogle Scholar
  44. 44.
    Nägele G, Baur P, Klein R (1996) Physica A 231:49CrossRefGoogle Scholar
  45. 45.
    Baur P, Nägele G. Klein R (1996) Phys Rev E 53:6224CrossRefGoogle Scholar
  46. 46.
    Müller J, Schätzel K, published in Müller J (1993) PhD thesis, Universität Kiel, Germany.Google Scholar

Copyright information

© Steinkopff Verlag 1997

Authors and Affiliations

  • G. Nägele
    • 1
  • M. Watzlawek
    • 1
  • R. Klein
    • 1
  1. 1.Fakultät für PhysikUniversität KonstanzKonstanzGermany

Personalised recommendations