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.

  • Letter
  • Published:

Liquid-crystal-mediated self-assembly at nanodroplet interfaces

Nature volume 485, pages 86–89 (2012)Cite this article

Subjects

Abstract

Technological applications of liquid crystals have generally relied on control of molecular orientation at a surface or an interface1,2. Such control has been achieved through topography, chemistry and the adsorption of monolayers or surfactants2,3. The role of the substrate or interface has been to impart order over visible length scales and to confine the liquid crystal in a device. Here, we report results from a computational study of a liquid-crystal-based system in which the opposite is true: the liquid crystal is used to impart order on the interfacial arrangement of a surfactant. Recent experiments on macroscopic interfaces have hinted that an interfacial coupling between bulk liquid crystal and surfactant can lead to a two-dimensional phase separation of the surfactant at the interface4, but have not had the resolution to measure the structure of the resulting phases. To enhance that coupling, we consider the limit of nanodroplets, the interfaces of which are decorated with surfactant molecules that promote local perpendicular orientation of mesogens within the droplet. In the absence of surfactant, mesogens at the interface are all parallel to that interface. As the droplet is cooled, the mesogens undergo a transition from a disordered (isotropic) to an ordered (nematic or smectic) liquid-crystal phase. As this happens, mesogens within the droplet cause a transition of the surfactant at the interface, which forms new ordered nanophases with morphologies dependent on surfactant concentration. Such nanophases are reminiscent of those encountered in block copolymers5, and include circular, striped and worm-like patterns.

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: Model of the nematic LC droplet.
Figure 2: Representative configurations of nanodroplets.
Figure 3: Director contour lines and defect core as a function of temperature, corresponding to a surfactant concentration of x surf = 0.5.
Figure 4: Phase diagram showing the ordered patterns adopted by the surfactant at the droplet interface, as a function of temperature and composition.

Similar content being viewed by others

References

  1. Collins, P. J. & Hird, M. Introduction to Liquid Crystals Chemistry and Physics (Taylor and Francis, 2004)

    Google Scholar 

  2. Jerome, B. Surface effects and anchoring in liquid crystals. Rep. Prog. Phys. 54, 391–451 (1991)

    Article  ADS  CAS  Google Scholar 

  3. Shah, R. & Abbott, N. L. Principles for measurement of chemical exposure based on recognition-driven anchoring transitions in liquid crystals. Science 293, 1296–1299 (2001)

    Article  ADS  CAS  Google Scholar 

  4. Gupta, J., Meli, M., Teren, S. & Abbott, N. L. Elastic energy-driven phase separation of phospholipid monolayers at the nematic liquid-crystal-aqueous interface. Phys. Rev. Lett. 100, 048301 (2008)

    Article  ADS  Google Scholar 

  5. Bates, F. & Fredrickson, G. Block copolymers—designer soft materials. Phys. Today 52, 32–38 (1999)

    Article  CAS  Google Scholar 

  6. de Gennes, P. G. & Prost, J. The Physics of Liquid Crystals (Oxford University Press, 1995)

    Book  Google Scholar 

  7. Barón, M. Definitions of basic terms relating to low-molar-mass and polymer liquid crystals. Pure Appl. Chem. 73, 845–895 (2001)

    Article  Google Scholar 

  8. Price, A. & Schwartz, D. DNA hybridization-induced reorientation of liquid crystal anchoring at the nematic liquid crystal/aqueous interface. J. Am. Chem. Soc. 130, 8188–8194 (2008)

    Article  CAS  Google Scholar 

  9. Park, J. & Abbott, N. L. Ordering transitions in thermotropic liquid crystals induced by the interfacial assembly and enzymatic processing of oligopeptide amphiphiles. Adv. Mater. 20, 1185–1190 (2008)

    Article  CAS  Google Scholar 

  10. Sivakumar, S., Wark, K., Gupta, J., Abbott, N. L. & Caruso, F. Liquid crystal emulsions as the basis of biological sensors for the optical detection of bacteria and viruses. Adv. Funct. Mater. 19, 2260–2265 (2009)

    Article  CAS  Google Scholar 

  11. Price, A. & Schwartz, D. Fatty-acid monolayers at the nematic/water interface: phases and liquid-crystal alignment. J. Phys. Chem. B 111, 1007–1015 (2007)

    Article  CAS  Google Scholar 

  12. Fernández-Nieves, A. et al. Novel defect structures in nematic liquid crystal shells. Phys. Rev. Lett. 99, 157801 (2007)

    Article  ADS  Google Scholar 

  13. Fernández-Nieves, A., Link, D., Marquez, M. & Weitz, D. Topological changes in bipolar nematic droplets under flow. Phys. Rev. Lett. 98, 087801 (2007)

    Article  ADS  Google Scholar 

  14. Gupta, J., Sivakumar, S., Caruso, F. & Abbott, N. Size-dependent ordering of liquid crystals observed in polymeric capsules with micrometer and smaller diameter. Angew. Chem. 48, 1652–1655 (2009)

    Article  CAS  Google Scholar 

  15. Yamamoto, J. & Tanaka, H. Transparent nematic phase in a liquid-crystal-based emulsion. Nature 409, 321–325 (2001)

    Article  ADS  CAS  Google Scholar 

  16. Fernández-Nieves, A., Link, D. R. & Weitz, D. A. Polarization dependent Bragg diffraction and electro-optic switching of three-dimensional assemblies of nematic liquid crystal droplets. Appl. Phys. Lett. 88, 121911 (2006)

    Article  ADS  Google Scholar 

  17. Humar, M., Ravnik, M., Pajk, S. & Musevic, I. Electrically tunable liquid crystal optical microresonators. Nature Photon. 3, 595–600 (2009)

    Article  ADS  CAS  Google Scholar 

  18. Yokohama, H. Tunable whispers. Nature Photon. 3, 560–561 (2009)

    Article  ADS  Google Scholar 

  19. Lin, I. et al. Endotoxin-induced structural transformations in liquid crystalline droplets. Science 332, 1297–1300 (2011)

    Article  ADS  CAS  Google Scholar 

  20. Luckhurst, G. R. & Simmonds, P. S. J. Computer simulation studies of anisotropic systems. XII. Parameterization of the Gay-Berne potential for model mesogens. Mol. Phys. 80, 233–252 (1993)

    Article  ADS  CAS  Google Scholar 

  21. Jackson, A., Myerson, J. & Stellacci, F. Spontaneous assembly of subnanometre-ordered domains in the ligand shell of monolayer-protected nanoparticles. Nature Mater. 3, 330–336 (2004)

    Article  ADS  CAS  Google Scholar 

  22. Singh, C. et al. Entropymediated patterning of surfactant-coated nanoparticles and surfaces. Phys. Rev. Lett. 99, 226106 (2007)

    Article  ADS  Google Scholar 

  23. Kotov, N. & Stellacci, F. Frontiers in nanoparticle research: toward greater complexity of structure and function of nanomaterials. Adv. Mater. 20, 4221–4222 (2008)

    Article  CAS  Google Scholar 

  24. Juffer, A. H. & Berendsen, H. J. C. Dynamical surface boundary conditions: a simple boundary model for molecular dynamics simulations. Mol. Phys. 79, 623–644 (1993)

    Article  ADS  CAS  Google Scholar 

  25. Frenkel, D. & Smith, B. Understanding Molecular Simulations—From Algorithms to Applications (Academic Press, 1996)

    Google Scholar 

  26. Allen, M. & Tildesley, D. Computer Simulation of Liquids (Oxford Science Publications, 1987)

    MATH  Google Scholar 

  27. Gay, J. G. & Berne, B. J. Modification of the overlap potential to mimic a linear site-site potentials. J. Chem. Phys. 74, 3316–3319 (1981)

    Article  ADS  CAS  Google Scholar 

  28. Ilnytskyi, M. & Wilson, M. R. A domain decomposition molecular dynamics program for the simulation of flexible molecules of spherically-symmetrical and nonspherical sites. II. Extension to NVT and NPT ensembles. Comput. Phys. Commun. 148, 43–58 (2002)

    Article  ADS  CAS  Google Scholar 

Download references

Acknowledgements

The continuum analysis of liquid crystal interfaces and the development of the corresponding theory were supported by the Department of Energy, Basic Energy Sciences, Biomaterials Program (DE-SC0004025). The calculations of surfactant organization at nanodroplet interfaces were supported by the National Science Foundation (DMR-1121288). The calculations reported here were performed on computational facilities supported by the National Science Foundation (DMR-1121288).

Author information

Authors and Affiliations

  1. Departamento de Física, Universidad Autónoma Metropolitana-Iztapalapa, Apartado Postal 55-534, México 09340, Distrito Federal, México,

    J. A. Moreno-Razo

  2. Department of Chemistry and Biochemistry Delaware Valley College, Doylestown, 18901, Pennsylvania, USA

    E. J. Sambriski

  3. Department of Chemical and Biological Engineering University of Wisconsin-Madison, Madison, 53706, Wisconsin, USA

    N. L. Abbott

  4. Departamento de Materiales, Universidad Nacional de Colombia, Sede Medellín, Bloque M3-050, Medellin, Colombia,

    J. P. Hernández-Ortiz

  5. Department of Chemical and Biological Engineering, University of Wisconsin-Madison, Madison, 53706, Wisconsin, USA

    J. J. de Pablo

Authors
  1. J. A. Moreno-Razo
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. E. J. Sambriski
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. N. L. Abbott
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. J. P. Hernández-Ortiz
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. J. J. de Pablo
    View author publications

    You can also search for this author in PubMed Google Scholar

Contributions

J.A.M.-R. performed the molecular dynamics and Monte Carlo simulations presented in this work. E.J.S. provided critical analysis of droplet structures. N.L.A. was involved in study design. J.P.H.-O. performed the continuum calculations presented in this work. J.J.d.P. designed the study, analysed data, and wrote the paper. All authors discussed the results and commented on the manuscript.

Corresponding author

Correspondence to J. J. de Pablo.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Supplementary information

Supplementary Information

This file contains Supplementary Text and Data 1- 4, Supplementary References and Supplementary figures 1-7. (PDF 4772 kb)

PowerPoint slides

Rights and permissions

Reprints and permissions

About this article

Cite this article

Moreno-Razo, J., Sambriski, E., Abbott, N. et al. Liquid-crystal-mediated self-assembly at nanodroplet interfaces. Nature 485, 86–89 (2012). https://doi.org/10.1038/nature11084

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/nature11084

This article is cited by

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.

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