Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Article
  • Published:

Nanoscale effects leading to non-Einstein-like decrease in viscosity

Nature Materials volume 2, pages 762–766 (2003)Cite this article

Abstract

Nanoparticles have been shown to influence mechanical properties; however, transport properties such as viscosity have not been adequately studied. This might be due to the common observation that particle addition to liquids produces an increase in viscosity, even in polymeric liquids, as predicted by Einstein nearly a century ago. But confinement and surface effects provided by nanoparticles have been shown to produce conformational changes to polymer molecules, so it is expected that nanoparticles will affect the macroscopic viscosity. To minimize extraneous enthalpic or other effects, we blended organic nanoparticles, synthesized by intramolecular crosslinking of single polystyrene chains, with linear polystyrene macromolecules. Remarkably, the blend viscosity was found to decrease and scale with the change in free volume introduced by the nanoparticles and not with the decrease in entanglement. Indeed, the entanglements did not seem to be affected at all, suggesting unusual polymer dynamics.

This is a preview of subscription content, access via your institution

Access options

Buy this article

  • Purchase on Springer Link
  • Instant access to full article PDF
Buy now

Prices may be subject to local taxes which are calculated during checkout

Figure 1: Diagram of the intramolecularly crosslinked nanoparticles produced from linear-chain precursors having pendent crosslinking groups.
Figure 2: SANS spectrum for lightly and tightly crosslinked nanoparticles, demonstrating the particle-like nature of the nanoparticles when sufficient crosslinking is present.
Figure 3: SANS spectrum for tightly crosslinked nanoparticles (Mr 52K) blended with linear deuterated polystyrene (Mr 63K) at 50 wt% with the incoherent background subtracted from the intensity.
Figure 4: Viscosity and glass-transition temperature (Tg) for Mr 52K tightly crosslinked nanoparticles (NP 52K), Mr 75K linear polystyrene (PS 75K) and their blends.
Figure 5: Change in viscosity with temperature and nanoparticle concentration.

Similar content being viewed by others

References

  1. Einstein, A. On the theory of Brownian movement. Ann. Phys. (Leipz.) 19, 371–381 (1906).

    Article  CAS  Google Scholar 

  2. VanDerWerff, J.C. & de Kruif, C.G. Hard-sphere colloidal dispersions: the scaling of rheological properties with particle size, volume fraction, and shear rate. J. Rheol. 33, 421–454 (1989).

    Article  CAS  Google Scholar 

  3. Russel, W.B., Saville, D.A. & Schowalter, W.R. Colloidal Dispersions (Cambridge Univ. Press, 1989).

    Book  Google Scholar 

  4. Metzner, A.B. Rheology of suspensions in polymeric liquids. J. Rheol. 29, 739–775 (1985).

    Article  CAS  Google Scholar 

  5. Krishnamoorti, R., Ren, J. & Silva, A.S. Shear response of layered silicate nanocomposites. J. Chem. Phys. 114, 4968–4973 (2001).

    Article  CAS  Google Scholar 

  6. Siegel, R.W. Exploring mesoscopia: the bold new world of nanostructures. Phys. Today 46 (October), 64–68 (1993).

    Article  CAS  Google Scholar 

  7. Mayo, M.J., Siegel, R.W., Narayanasamy, A. & Nix, W.D. Mechanical properties of nanophase TiO2 as determined by nanoindentation. J. Mater. Res. 5, 1073–1082 (1990).

    Article  CAS  Google Scholar 

  8. Mayo, M.J., Siegel, R.W., Liao, Y.X. & Nix, W.D. Nanoindentation of nanocrystalline ZnO. J. Mater. Res. 7, 973–979 (1992).

    Article  CAS  Google Scholar 

  9. Roberts, C., Cosgrove, T., Schmidt, R.G. & Gordon, G.V. Diffusion of poly(dimethylsiloxane) mixtures with silicate nanoparticles. Macromolecules 34, 538–543 (2001).

    Article  CAS  Google Scholar 

  10. O'Brien, V.T. & Mackay, M.E. Stress components and shear thickening of concentrated hard sphere suspensions. Langmuir 16, 7931–7938 (2000).

    Article  CAS  Google Scholar 

  11. Harth, E. et al. A facile approach to architecturally defined nanoparticles via intramolecular chain collapse. J. Am. Chem. Soc. 124, 8653–8660 (2002).

    Article  CAS  Google Scholar 

  12. Antonietti, M., Pakula, T. & Bremser, W. Rheology of small spherical polystyrene microgels: a direct proof for a new transport mechanism in bulk polymers besides reptation. Macromolecules 28, 4227–4233 (1995).

    Article  CAS  Google Scholar 

  13. Higgins, J.S. & Benoît, H.C. Polymers and Neutron Scattering (Clarendon, Oxford, 2002).

    Google Scholar 

  14. Tande, B.M. et al. Viscometric, hydrodynamic and conformational properties of dendrimers and dendrons. Macromolecules 34, 8580–8585 (2001).

    Article  CAS  Google Scholar 

  15. Burchard, W. Solution properties of branched macromolecules. Adv. Polym. Sci. 143, 113–195 (1999).

    Article  CAS  Google Scholar 

  16. Burchard, W., Kajiwara, K. & Nerger, D. Static and dynamic scattering behavior of regularly branched chains: a model of soft-sphere microgels. J. Polym. Sci. Polym. Phys. 20, 157–171 (1982).

    Article  CAS  Google Scholar 

  17. Cosgrove, T., Griffiths, P.C. & Lloyd, P.M. Polymer adsorption. The effect of the relative sizes of polymer and particle. Langmuir 11, 1457–1463 (1995).

    Article  CAS  Google Scholar 

  18. Krieger, I.M. & Dougherty, T.J. A mechanism for non-Newtonian flow in suspensions of rigid spheres. Trans. Soc. Rheol. 3, 137–152 (1959).

    Article  CAS  Google Scholar 

  19. Mackay, M.E. & Henson, D.J. The effect of molecular mass and temperature on the slip of polystyrene melts at low stress levels. J. Rheol. 42, 1505–1517 (1998).

    Article  CAS  Google Scholar 

  20. Starr, F.W., Schrøder, T.B. & Glotzer, S.C. Molecular dynamics simulation of a polymer melt with a nanoscopic particle. Macromolecules 35, 4481–4492 (2002).

    Article  CAS  Google Scholar 

  21. Varnik, F., Baschnagel, J. & Binder, K. Reduction of the glass transition temperature in polymer films: a molecular-dynamics study. Phys. Rev. E 65, 021507 (2002).

    Article  CAS  Google Scholar 

  22. Ferry, J.D. Viscoelastic Properties of Polymers (Wiley, New York, 1980).

    Google Scholar 

  23. Batchelor, G.K. The effect of Brownian motion on the bulk stress in a suspension of spherical particles. J. Fluid Mech. 83, 97–117 (1977).

    Article  Google Scholar 

  24. Merkel, T.C. et al. Ultrapermeable, reverse-selective nanocomposite membranes. Science 296, 519–522 (2002).

    Article  CAS  Google Scholar 

  25. Xue, G., Lu, Y., Shi, G. & Dai, Q. Glass transition of expanded polystyrene coils. Polymer 35, 892–894 (1994).

    Article  CAS  Google Scholar 

  26. deGennes, P.G. Reptation of a polymer chain in the presence of fixed obstacles. J. Chem. Phys. 55, 572–579 (1971).

    Article  Google Scholar 

  27. Doi, M. & Edwards, S.F. The Theory of Polymer Dynamics (Clarendon, Oxford, 1986).

    Google Scholar 

Download references

Acknowledgements

This work was supported by NSF-CTS 0296166, NSF MRSEC DMR-0213618 and NSF-NIRT 0210247, with partial support from the Dow Chemical Company.

Author information

Authors and Affiliations

  1. Department of Chemical Engineering and Materials Science, Michigan State University, East Lansing, 48824, Michigan, USA

    Michael E. Mackay, Tien T. Dao & Anish Tuteja

  2. National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, MS 8562, 20899, Maryland, USA

    Derek L. Ho

  3. IBM Almaden Research Center, 650 Harry Road, San Jose, 95120, California, USA

    Brooke Van Horn, Ho-Cheol Kim & Craig J. Hawker

Authors
  1. Michael E. Mackay
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Tien T. Dao
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Anish Tuteja
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Derek L. Ho
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. Brooke Van Horn
    View author publications

    You can also search for this author in PubMed Google Scholar

  6. Ho-Cheol Kim
    View author publications

    You can also search for this author in PubMed Google Scholar

  7. Craig J. Hawker
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Michael E. Mackay.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Mackay, M., Dao, T., Tuteja, A. et al. Nanoscale effects leading to non-Einstein-like decrease in viscosity. Nature Mater 2, 762–766 (2003). https://doi.org/10.1038/nmat999

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/nmat999

This article is cited by

Search

Advanced search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing