Letter | Published:

Reduction of frictional forces between solid surfaces bearing polymer brushes

Nature volume 370, pages 634636 (25 August 1994) | Download Citation

Subjects

Abstract

THE use of lubricants to reduce friction and wear between rubbing surfaces has been documented since antiquity1–3. Recent approaches have focused on boundary lubrication by surfactant-like species coating the surfaces, whereby the friction between them is replaced by the weaker forces required for shear of adhesive contacts between the surfactant layers3,4. An alternative approach is to tether polymer chains to the surfaces by one end which, when swollen by a solvent, then act as molecular ‘brushes’ that may facilitate sliding. The normal forces between sliding brush-bearing surfaces have been previously investigated5,6, but the lateral forces, which are the most important from the point of view of lubrication, are harder to measure. Here we report the measurement of lateral forces in such a system. We find a striking reduction in the effective friction coefficients μb between the surfaces to below our detection limit (μb < 0.001), for contact pressures of around 1 MPa and sliding velocities from zero to 450 nm s−1. We believe that this effect is due to the long-ranged repulsion, of entropic origin, between the brushes, which acts to keep the surfaces apart while maintaining a relatively fluid layer at the interface between them.

Access optionsAccess options

Rent or Buy article

Get time limited or full article access on ReadCube.

from$8.99

All prices are NET prices.

References

  1. 1.

    Friction (Doubleday, New York, 1973).

  2. 2.

    History of Tribology (Longmans, London, 1979).

  3. 3.

    Singer, I. L. & Pollock, H. M. (eds) Fundamentals of Friction: Microscopic and Macroscopic Processes (Kluwer, Dordrecht, 1992).

  4. 4.

    in Microscopic aspects of adhesion and lubrication (ed. Georges, J. M.) 651–682 (Elsevier, New York, 1982).

  5. 5.

    , & Nature 352, 143–145 (1991).

  6. 6.

    Pure appl. Chem. 64, 1577–1584 (1992).

  7. 7.

    J. chem. Phys. 78, 6906–6913 (1983).

  8. 8.

    , , & J. chem. Phys. 93, 1895–1906 (1990).

  9. 9.

    , , & Macromolecules 23, 571–580 (1990).

  10. 10.

    J. Phys. Paris 38, 983–989 (1977).

  11. 11.

    Adv. Colloid Interface Sci. 27, 189–207 (1987).

  12. 12.

    , & Adv. Polymer Sci. 100, 31–96 (1991).

  13. 13.

    Principles of Polymer Chemistry (Cornell Univ. Press, Ithaca, 1953).

  14. 14.

    in Scaling Concepts in Polymer Physics (Cornell Univ. Press, Ithaca, 1975).

  15. 15.

    , & Macromolecules 23, 824–830 (1990).

  16. 16.

    Langmuir 8, 989–995 (1992).

  17. 17.

    & J. non-cryst. Solids 131–133, 221–224 (1991).

  18. 18.

    , & Trans. Soc. Rheology 11, 267–285 (1967).

  19. 19.

    & Macromolecules 6, 366–372 (1973).

  20. 20.

    & The Friction and Lubrication of Solids (Clarendon, Oxford, 1950).

  21. 21.

    Nature 184, 1284–1286 (1959).

  22. 22.

    in Lubrication and Wear in Joints (ed. Wright, V.) Ch. 14. (Sector, London, 1969).

Download references

Author information

Affiliations

  1. Department of Materials and Interfaces, Weizmann Institute of Science, Rehovot 76100, Israel

    • Jacob Klein
    • , Eugenia Kumacheva
    • , Diana Mahalu
    •  & Dvora Perahia
  2. Exxon Research and Engineering Company, Annadale, New Jersey 08801, USA

    • Lewis J. Fetters

Authors

  1. Search for Jacob Klein in:

  2. Search for Eugenia Kumacheva in:

  3. Search for Diana Mahalu in:

  4. Search for Dvora Perahia in:

  5. Search for Lewis J. Fetters in:

About this article

Publication history

Received

Accepted

Published

DOI

https://doi.org/10.1038/370634a0

Further reading

Comments

By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.