Surface visco-elastic modes in a spread film of a block copolymer

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Andrew S. Brown, Randal W. Richards, D. Martin A. Buzza and Tom C. B. McLeish


Abstract

A linear diblock copolymer of polymethyl methacrylate and poly-4-vinyl pyridine quaternised with ethyl bromide has been spread as a thin film at the air/water interface and the properties of the capillary waves obtained using surface quasi-elastic light scattering. The data have been analysed for surface visco-elastic parameters on the basis of the complete absence of any transverse shear viscosity in the spread film. A resonance between capillary and dilatational modes was observed at a block copolymer surface concentration of 0.8 mg m-2. At this surface concentration the frequency dependence of the surface tension, dilatational modulus and dilatational viscosity exhibited behaviour which suggested that spread film could be represented as a Maxwell fluid with a relaxation time of ca. 3 µs. This Maxwell fluid model also described the dependence of an ‘apparent’ relaxation time of the dilatational mode on the surface concentration for a capillary wave of fixed wavenumber. A comparison of the observed dispersion behaviour (damping as a function of capillary wave frequency) with that predicted by theoretical forms of the dispersion equation, showed that there was no need to include a postulated coupling factor. This observation concurred with the modest dimensions of the surface region occupied by the quaternised vinyl pyridine blocks.


References

  1. J. Lucassen, Trans. Faraday Soc., 1968, 64, 2221 RSC.
  2. V. G. Levich, Physicochemical Hydrodynamics, Prentice-Hall, Englewood Cliffs, NJ, 1962 Search PubMed.
  3. A. B. Pippard, The Physics of Vibration, Omnibus Edition, Cambridge University Press, Cambridge, 1989 Search PubMed.
  4. A. B. Pippard, Response and Stability, Cambridge University Press, Cambridge, 1985 Search PubMed.
  5. J. D. Ferry, Visco-Elastic Properties of Polymers, John Wiley, New York, 1980 Search PubMed.
  6. F. C. Goodrich, Proc. R. Soc. London A, 1981, 374, 341.
  7. E. H. Lucassen-Reynders and J. Lucassen, Adv. Colloid Interface Sci., 1969, 2, 347 CrossRef.
  8. M. Hennenberg, X.-L. Chu, A. Sanfeld and M. G. Velarde, J. Colloid Interface Sci., 1992, 150, 7 CAS.
  9. X.-L. Chu and M. G. Velarde, PCH PhysicoChem. Hydrodyn., 1988, 10, 727 Search PubMed.
  10. M. G. Velarde, Philos. Trans. R. Soc. London Ser. A., 1998, 356, 829 Search PubMed.
  11. J. C. Earnshaw and E. McCoo, Langmuir, 1995, 11, 1087 CrossRef CAS.
  12. J. L. Harden and H. Pleiner, Phys. Rev. E, 1994, 49, 1411 CrossRef CAS.
  13. F. C. Goodrich, J. Phys. Chem., 1962, 66, 1858 CAS.
  14. S. K. Peace, R. W. Richards and N. Williams, Langmuir, 1998, 14, 667 CrossRef CAS.
  15. D. M. A. Buzza, J. L. Jones, T. C. B. McLeish and R. W. Richards, J. Chem. Phys., 1998, 109, 5008 CrossRef CAS.
  16. R. H. Katyl and K. U. Ingard, Phys. Rev. Lett., 1968, 20, 248 CrossRef.
  17. C. Booth, R. W. Richards, M. R. Taylor and G. E. Yu, J. Phys. Chem. B, 1998, 102, 2001 CrossRef CAS.
  18. J. F. Crilly and J. C. Earnshaw, Biophys. J., 1983, 41, 197 CrossRef CAS.
  19. J. C. Earnshaw and P. J. Winch, Thin Solid Films, 1988, 159, 159 CrossRef CAS.
  20. J. C. Earnshaw and D. J. Sharpe, J. Chem. Soc., Faraday Trans., 1996, 92, 611 RSC.
  21. R. W. Richards and M. R. Taylor, J. Chem. Soc., Faraday Trans., 1996, 92, 601 RSC.
  22. R. W. Richards, B. R. Rochford and M. R. Taylor, Macromolecules, 1996, 29, 1980 CrossRef CAS.
  23. R. W. Richards and M. R. Taylor, Macromolecules, 1997, 30, 3892 CrossRef CAS.
  24. F. E. Runge, H. Yu and D. Woermann, Ber. Bunsen-Ges. Phys. Chem., 1994, 98, 1046 CAS.
  25. K. Sakai and K. Takagi, Langmuir, 1994, 10, 257 CrossRef CAS.
  26. D. Sharpe and J. Eastoe, Langmuir, 1995, 11, 4636 CrossRef CAS.
  27. D. Sharpe and J. Eastoe, Langmuir, 1996, 12, 2303 CrossRef.
  28. M. van den Tempel and E. H. Lucassen-Reynders, Adv. Colloid Interface Sci., 1983, 18, 281 CrossRef CAS.
  29. S. K. Peace, R. W. Richards, M. R. Taylor, J. R. P. Webster and N. Williams, Macromolecules, 1998, 31, 1261 CrossRef CAS.
  30. P. G. de Gennes, Macromolecules, 1980, 13, 1069 CrossRef CAS.
  31. J. Lyklema, Fundamentals of Interface and Colloid Science, Academic Press, London, 1991 Search PubMed.
  32. D. Langevin, in Light Scattering by Liquid Surfaces and Complementary Techniques, ed. D. Langevin, Dekker, New York, 1992 Search PubMed.
  33. R. W. Richards, B. R. Rochford and M. R. Taylor, Macromolecules, 1996, 29, 1980 CrossRef CAS.
  34. J. C. Earnshaw, R. C. McGivern, A. C. McLaughlin and P. J. Winch, Langmuir, 1990, 6, 649 CrossRef CAS.
  35. J. C. Earnshaw, R. C. McGivern and P. J. Winch, J. Phys., 1988, 49, 1271 Search PubMed.
  36. A. S. Brown and R. W. Richards, unpublished data.
  37. H. Dautzenberg, W. Jaeger, W. Kotz, B. Phillipp, C. Seidel and D. Stscherbina, Polyelectrolytes Formation, Characterization and Application, Hanser, Munich, 1994 Search PubMed.
  38. J. C. Earnshaw and A. C. McLaughlin, Proc. R. Soc. London A, 1991, 433, 663.
  39. J. C. Earnshaw and A. C. McLaughlin, Proc. R. Soc. London A, 1993, 440, 519 CAS.
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