Skip to main content

Thank you for visiting 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.

Shape-memory nanoparticles from inherently non-spherical polymer colloids


Samples of polymeric materials generally have no intrinsic shape; rather their macroscopic form is determined by external forces such as surface tension and memory of shear (for example, during extrusion, moulding or embossing). Hence, in the molten state, the thermodynamically most stable form for polymer (nano)particles is spherical. Here, we present the first example of polymer nanoparticles that have an intrinsic non-spherical shape. We observe the formation of high-aspect-ratio ellipsoidal polymer nanoparticles, of controlled diameter, made from main-chain liquid crystalline polymers using a mini-emulsion technique. The ellipsoidal shape is shown to be an equilibrium (reversible) characteristic and a direct result of the material shape memory when a liquid crystal nanoparticle is in its monodomain form.

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

Relevant articles

Open Access articles citing this article.

Access options

Rent or buy this article

Get just this article for as long as you need it


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

Figure 1: Chemical structures of the polymers used in this study.
Figure 2: SEM images of main-chain polyether nanoparticles with different morphologies and sizes.
Figure 3: SEM images of main-chain polyether nanoparticles.
Figure 4: SEM images of F8BT nanoparticles with different shapes and sizes.
Figure 5: SEM images of PFO nanoparticles with different shapes and sizes.
Figure 6: SEM images of annealed PFO nanoparticles.


  1. Donald, A. M. & Windle, A. H. Liquid Crystalline Polymers (Cambridge Univ. Press, Cambridge, 1992).

    Google Scholar 

  2. Warner, M. & Terentjev, E. M. Liquid Crystal Elastomers (Clarendon, Oxford, 2003).

    Google Scholar 

  3. Finkelmann, H., Nishikawa, E., Pereira, G. G. & Warner, M. A new opto-mechanical effect in solids. Phys. Rev. Lett. 87, 015501 (2001).

    Article  CAS  Google Scholar 

  4. Küpfer, J. & Finkelmann, H. Liquid-crystal elastomers: influence of the orientational distribution of the crosslinks on the phase behaviour and reorientation processes. Macromol. Chem. Phys. 195, 1353–1367 (1994).

    Article  Google Scholar 

  5. Joannopoulos, J. D., Villeneuve, P. R. & Fan, S. Photonic crystals: putting a new twist on light. Nature 386, 143–149 (1997).

    Article  CAS  Google Scholar 

  6. Lu, Y., Yin, Y. & Xia, Y. Three-dimensional photonic crystals with non-spherical colloids as building blocks. Adv. Mater. 13, 415–420 (2001).

    Article  CAS  Google Scholar 

  7. Xia, Y., Gates, B., Yin, Y. & Lu, Y. Monodispersed colloidal spheres: old materials with new applications. Adv. Mater. 12, 693–713 (2000).

    Article  CAS  Google Scholar 

  8. Matijevic, E. Uniform inorganic colloid dispersions. Achievements and challenges. Langmuir 10, 8–16 (1994).

    Article  CAS  Google Scholar 

  9. Morales, M. P., Gonzalez-Carreno, T. & Serna, C. J. The formation of α-Fe2O3 monodispersed particles in solution. J. Mater. Res. 7, 2538–2545 (1992).

    Article  CAS  Google Scholar 

  10. van Dillen, T., van Blaaderen, A. & Polman, A. Shaping colloidal assemblies. Mater. Today 7, 40–46 (2004).

    Article  CAS  Google Scholar 

  11. Jiang, P., Bertone, J. F. & Colvin, V. L. A lost-wax approach to monodisperse colloids and their crystals. Science 291, 453–457 (2001).

    Article  CAS  Google Scholar 

  12. Ho, C. C., Keller, A., Odell, J. A. & Ottewill, R. H. Preparation of monodisperse ellipsoidal polystyrene particles. Colloid Polym. Sci. 271, 469–479 (1993).

    Article  CAS  Google Scholar 

  13. Lu, Y., Yin, Y. & Xia, Y. Preparation and characterization of micrometer-sized 'egg shells'. Adv. Mater. 13, 271–274 (2001).

    Article  CAS  Google Scholar 

  14. Percec, V. & Kawasumi, M. Liquid-crystalline polyethers based on conformational isomerism. 18. Polyethers based on a combined mesogenic unit containing rigid and flexible groups: 1-(4-hydroxy-4′-biphenyl)-2-(4-hydroxyphenyl)butane. Macromolecules 24, 6318–6324 (1991).

    Article  CAS  Google Scholar 

  15. Grell, M., Bradley, D. D. C., Inbasekaran, M. & Woo, E. P. A glass-forming conjugated main-chain liquid crystal polymer for polarized electroluminescence applications. Adv. Mater. 9, 798–802 (1997).

    Article  CAS  Google Scholar 

  16. Landfester, K. et al. Semiconducting polymer nanospheres in aqueous dispersion prepared by a miniemulsion process. Adv. Mater. 14, 651–655 (2002).

    Article  CAS  Google Scholar 

  17. Ciferri, A., Krigbaum, W. R. & Meyer, R. B. Polymer Liquid Crystals (Academic, New York, 1982).

    Google Scholar 

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

    Google Scholar 

  19. Elias, F., Clarke, S. M., Peck, R. & Terentjev, E. M. Equilibrium textures in main-chain liquid crystalline polymers. Europhys. Lett. 47, 442–448 (1999).

    Article  CAS  Google Scholar 

  20. Elias, F., Clarke, S. M., Peck, R. & Terentjev, E. M. Nematic order drives phase separation in polydisperse liquid crystalline polymers. Macromolecules 33, 2060–2068 (2000).

    Article  CAS  Google Scholar 

  21. Landfester, K. Polyreactions in miniemulsions. Macromol. Rapid Commun. 22, 896–936 (2001).

    Article  Google Scholar 

  22. Fridrikh, S. V. & Terentjev, E. M. Polydomain–monodomain transition in nematic elastomers. Phys. Rev. E 60, 1847–1857 (1999).

    Article  CAS  Google Scholar 

Download references


Z.Y. thanks the Overseas Research Studentship and Gates Cambridge Trust for financial support.

Author information

Authors and Affiliations


Corresponding author

Correspondence to Wilhelm T. S. Huck.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Supplementary information

Supplementary Information

Supplementary table 1 and supplementary figures 1 and 2 (PDF 1275 kb)

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Yang, Z., Huck, W., Clarke, S. et al. Shape-memory nanoparticles from inherently non-spherical polymer colloids. Nature Mater 4, 486–490 (2005).

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI:

This article is cited by


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