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:

Memory and topological frustration in nematic liquid crystals confined in porous materials

Abstract

Orientational ordering is key to functional materials with switching capability, such as nematic liquid crystals and ferromagnetic and ferroelectric materials. We explored the confinement of nematic liquid crystals in bicontinuous porous structures with smooth surfaces that locally impose normal orientational order on the liquid crystal. We find that frustration leads to a high density of topological defect lines permeating the porous structures, and that most defect lines are made stable by looping around solid portions of the confining material. Because many defect trajectories are possible, these systems are highly metastable and efficient in memorizing the alignment forced by external fields. Such memory effects have their origin in the topology of the confining surface and are maximized in a simple periodic bicontinuous cubic structure. We also show that nematic liquid crystals in random porous networks exhibit a disorder-induced slowing-down typical of glasses that originates from activated collisions and rearrangements of defect lines. Our findings offer the possibility to functionalize orientationally ordered materials through topological confinement.

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

Access options

Buy this article

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

Figure 1: Patterns of DLs in porous media with various topologies.
Figure 2: Memory effects in NLCs confined in a bicontinuous cubic porous medium (BC).
Figure 3: Relaxation of the nematic order Q after turning off the field.
Figure 4: ℓ and T dependencies of the parameters characterizing the order-parameter relaxation.
Figure 5: Snapshots of defect lines (red lines) in RPM at selected times during their relaxation after removal of the field.
Figure 6: Functionalization of NLC by confinements for memory applications.

Similar content being viewed by others

References

  1. Kleman, M. & Lavrentovich, O. D. Soft Matter Physics: An Introduction (Springer, 2003).

    Google Scholar 

  2. Crawford, G. P. & Žumer, S. (eds) Liquid Crystals in Complex Geometries Formed by Polymer and Porous Networks (Taylor and Francis, 1996).

  3. Kim, J-H., Yoneya, M. & Yokoyama, H. Tristable nematic liquid-crystal device using micropatterned surface alignment. Nature 420, 159–162 (2002).

    Article  CAS  Google Scholar 

  4. Golemme, A., Žumer, S., Allender, D. A. & Doane, J. W. Continuous nematic–isotropic transition in submicron-size liquid-crystal droplets. Phys. Rev. Lett. 61, 2937–2940 (1988).

    Article  CAS  Google Scholar 

  5. Terentjev, E. M. Disclination loops, standing alone and around solid particles, in nematic liquid-crystals. Phys. Rev. E 51, 1330–1337 (1995).

    Article  CAS  Google Scholar 

  6. Poulin, P., Stark, H., Lubensky, T. C. & Weitz, D. A. Novel colloidal interactions in anisotropic fluids. Science 275, 1770–1773 (1997).

    Article  CAS  Google Scholar 

  7. Stark, H. Physics of colloidal dispersions in nematic liquid crystals. Phys. Rep. 351, 387–474 (2001).

    Article  CAS  Google Scholar 

  8. Bradač, Z., Kralj, S. & Žumer, S. Molecular dynamics study of nematic structures confined to a cylindrical cavity. Phys. Rev. E 58, 7447–7454 (1998).

    Article  Google Scholar 

  9. Araki, T. & Tanaka, H. Colloidal aggregation in a nematic liquid crystal: Topological arrest of particles by a single stroke disclination line. Phys. Rev. Lett. 97, 127801 (2006).

    Article  Google Scholar 

  10. Wu, X., Goldburg, W. I., Liu, M. X. & Xue, J. Z. Slow dynamics of isotropic–nematic phase transition in silica gels. Phys. Rev. Lett. 69, 470–473 (1992).

    Article  CAS  Google Scholar 

  11. Bellini, T. et al. Phase behavior of the liquid crystal 8CB in a silica aerogel. Phys. Rev. Lett. 69, 788–791 (1992).

    Article  CAS  Google Scholar 

  12. Iannacchione, G. S., Crawford, G. P., Žumer, S., Doane, J. W. & Finotello, D. Randomly constrained orientational order in porous glass. Phys. Rev. Lett. 71, 2595–2598 (1993).

    Article  CAS  Google Scholar 

  13. Bellini, T. et al. Nematics with quenched disorder: How long will it take to heal? Phys. Rev. Lett. 88, 245506 (2002).

    Article  CAS  Google Scholar 

  14. Buscaglia, M. et al. Memory effects in nematics with quenched disorder. Phys. Rev. E 74, 011706 (2006).

    Article  CAS  Google Scholar 

  15. Kang, D., Maclennan, J. E., Clark, N. A., Zakhidov, A. A. & Baughman, R. H. Electro-optic behavior of liquid-crystal-filled silica opal photonic crystals: Effect of liquid-crystal alignment. Phys. Rev. Lett. 86, 4052–4055 (2001).

    Article  CAS  Google Scholar 

  16. Radzihovsky, L. & Toner, J. Smectic liquid crystals in random environments. Phys. Rev. B 60, 206–257 (1999).

    Article  CAS  Google Scholar 

  17. Feldman, D. E. Quasi-long-range order in nematics confined in random porous media. Phys. Rev. Lett. 84, 4886–4889 (2000).

    Article  CAS  Google Scholar 

  18. Rutunno, M. et al. Nematics with quenched disorder: Pinning out the origin of memory. Phys. Rev. Lett. 94, 097802 (2005).

    Article  Google Scholar 

  19. Lammert, P. E., Rokhsar, D. S. & Toner, J. Topology and nematic ordering. I. A Gauge theory. Phys. Rev. E 52, 1778–1800 (1995).

    Article  CAS  Google Scholar 

  20. Cang, H., Novikov, V. N. & Fayer, M. D. Experimental observation of a nearly logarithmic decay of orientational correlation function in supercooled liquids on the picosecond-to-nanosecond time scales. Phys. Rev. Lett. 90, 197401 (2003).

    Article  Google Scholar 

  21. Götze, W. & Sperl, M. Nearly logarithmic decay of correlations in glass-forming liquids. Phys. Rev. Lett. 92, 105701 (2004).

    Article  Google Scholar 

  22. Yin, Y., Shiyanovskii, S. V., Golovin, A. B. & Lavrentovich, O. D. Dielectric torque and orientation dynamics of liquid crystals with dielectric dispersion. Phys. Rev. Lett. 95, 087801 (2005).

    Article  CAS  Google Scholar 

  23. Mühlbauer, S. et al. Skyrmion lattice in a chiral magnet. Science 323, 915–919 (2009).

    Article  Google Scholar 

  24. Doria, M. M., Romaguera, A. R. de C., Milosevic, M. V. & Peeters, F. M. Threefold onset of vortex loops in superconductors with a magnetic core. Europhys. Lett. 79, 47006 (2007).

    Article  Google Scholar 

  25. Lebwohl, P. A. & Lasher, G. Nematic-liquid-crystal order—Monte Carlo calculation. Phys. Rev. A 6, 426–429 (1972).

    Article  Google Scholar 

  26. Fabbri, U. & Zannoni, C. A Monte Carlo investigation of the Lebwohl–Lasher lattice model in the vicinity of its orientational phase transition. Mol. Phys. 58, 763–788 (1986).

    Article  Google Scholar 

  27. de Gennes, P. G. & Prost, J. The Physics of Liquid Crystals 2nd edn (Oxford Univ. Press, 1993).

    Google Scholar 

  28. Binder, K. & Kob, W. Glassy Materials and Disordered Solids (World Scientific Pub., 2005).

    Book  Google Scholar 

  29. Ogielski, A. T. Dynamics of three-dimensional Ising spin-glasses in thermal equilibrium. Phys. Rev. B 32, 7384–7398 (1985).

    Article  CAS  Google Scholar 

  30. Onuki, A. Phase Transition Dynamics (Cambridge Unv. Press, 2002).

    Book  Google Scholar 

Download references

Acknowledgements

We thank C. P. Royall for a critical reading of the manuscript. This work was supported by a Grant in Aid from the Ministry of Education, Culture, Sports, Science, and Technology, Japan, and by the Cariplo Foundation (grant 2008-2413), Italy.

Author information

Authors and Affiliations

Authors

Contributions

T.B. and H.T. conceived the project, T.A. carried out numerical simulations, M.B. carried out experiments and all authors analysed the data and wrote the manuscript.

Corresponding authors

Correspondence to Tommaso Bellini or Hajime Tanaka.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Supplementary information

Supplementary Information

Supplementary Information (PDF 1776 kb)

Supplementary Movie

Supplementary Movie (MOV 2348 kb)

Supplementary Movie

Supplementary Movie (MOV 1195 kb)

Rights and permissions

Reprints and permissions

About this article

Cite this article

Araki, T., Buscaglia, M., Bellini, T. et al. Memory and topological frustration in nematic liquid crystals confined in porous materials. Nature Mater 10, 303–309 (2011). https://doi.org/10.1038/nmat2982

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/nmat2982

This article is cited by

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