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Electric-field-induced capillary attraction between like-charged particles at liquid interfaces


Nanometre- and micrometre-sized charged particles at aqueous interfaces are typically stabilized by a repulsive Coulomb interaction. If one of the phases forming the interface is a nonpolar substance (such as air or oil) that cannot sustain a charge, the particles will exhibit long-ranged dipolar repulsion1; if the interface area is confined, mutual repulsion between the particles can induce ordering2 and even crystallization3,4. However, particle ordering has also been observed in the absence of area confinement5, suggesting that like-charged particles at interfaces can also experience attractive interactions6. Interface deformations are known to cause capillary forces that attract neighbouring particles to each other, but a satisfying explanation for the origin of such distortions remains outstanding7,8. Here we present quantitative measurements of attractive interactions between colloidal particles at an oil–water interface and show that the attraction can be explained by capillary forces that arise from a distortion of the interface shape that is due to electrostatic stresses caused by the particles' dipolar field. This explanation, which is consistent with all reports on interfacial particle ordering so far, also suggests that the attractive interactions might be controllable: by tuning the polarity of one of the interfacial fluids, it should be possible to adjust the electrostatic stresses of the system and hence the interparticle attractions.

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Figure 1: Interfacial colloidal particle ordering induced by repulsive interactions.
Figure 2: Scatter plot showing positions of a seven-particle hexagonal crystallite on a water droplet of 24 µm radius.
Figure 3: Secondary interparticle potential minimum derived from experimental observations.
Figure 4: Sketch of the equipotential lines at the fluid interface and the resulting distortion of the oil–water interface.


  1. Pieranski, P. Two-dimensional interfacial colloidal crystals. Phys. Rev. Lett. 45, 569–572 (1980)

    Article  ADS  CAS  Google Scholar 

  2. Onada, G. Y. Direct observation of two-dimensional, dynamical clustering and ordering with colloids. Phys. Rev. Lett. 55, 226–229 (1985)

    Article  ADS  Google Scholar 

  3. Denkov, N. D., Velev, O. D., Kralchevsky, P. A. & Ivanov, I. B. Two-dimensional crystallization. Nature 361, 26 (1993)

    Article  ADS  Google Scholar 

  4. Wickmann, H. H. & Korley, J. N. Colloid crystal self-organization and dynamics at the air/water interface. Nature 393, 445–447 (1998)

    Article  ADS  Google Scholar 

  5. Ruiz-García, J., Gámez-Corrales, R. & Ivlev, B. I. Formation of two-dimensional colloidal voids, soap froths, and clusters. Phys. Rev. E 58, 660–663 (1998)

    Article  ADS  Google Scholar 

  6. Quesada-Pérez, M., Moncho-Jordá, A., Martínez-López, F. & Hidalgo-Álvarez, R. Probing interaction forces in colloidal monolayers: Inversion of structural data. J. Chem. Phys. 115, 10897–10902 (2001)

    Article  ADS  Google Scholar 

  7. Kralchevsky, P. A. & Denkov, N. D. Capillary forces and structuring in layers of colloid particles. Curr. Opin. Colloid Interf. Sci. 6, 383–401 (2001)

    Article  CAS  Google Scholar 

  8. Stamou, D., Duschl, C. & Johannsmann, D. Long-range attraction between colloidal spheres at the air-water interface: The consequence of an irregular meniscus. Phys. Rev. E 62, 5263–5272 (2000).

    Article  ADS  CAS  Google Scholar 

  9. Hurd, A. J. The electrostatic interaction between interfacial colloidal particles. J. Phys. A 18, L1055–L1060 (1985)

    Article  ADS  CAS  Google Scholar 

  10. Chan, D. Y. C., Henry, J. D. & White, L. R. The interaction of colloidal particles collected at fluid interfaces. J. Colloid Interf. Sci. 79, 410–418 (1981)

    Article  ADS  CAS  Google Scholar 

  11. Kralchevsky, P. A., Paunov, V. N., Ivanov, I. B. & Nagayama, K. Capillary meniscus interaction between colloidal particles attached to a liquid-fluid interface. J. Colloid Interf. Sci. 151, 79–94 (1992)

    Article  ADS  Google Scholar 

  12. Morse, D. C. & Witten, T. A. Droplet elasticity in weakly compressed emulsions. Europhys. Lett. 22, 549–555 (1993)

    Article  ADS  CAS  Google Scholar 

  13. Bowden, N., Terfort, A., Carbeck, J. & Whitesides, G. M. Self-assembly of mesoscale objects into ordered two-dimensional arrays. Science 276, 233–235 (1997)

    Article  CAS  Google Scholar 

  14. Kralchevsky, P. A. & Nagayama, K. Capillary interactions between particles bound to interfaces, liquid films and biomembranes. Adv. Colloid Interf. Sci. 85, 145–192 (2000)

    Article  CAS  Google Scholar 

  15. Goulian, M., Bruinsma, R. & Pincus, P. Long-range forces in heterogeneous fluid membranes. Europhys. Lett. 22, 145–150 (1993)

    Article  ADS  CAS  Google Scholar 

  16. Golestanian, R., Goulian, M. & Kardar, M. Fluctuation-induced interactions between rods on a membrane. Phys. Rev. E 54, 6725–6734 (1996)

    Article  ADS  CAS  Google Scholar 

  17. Landau, L. D. & Lifshitz, E. M. Electrodynamics of Continuous Media (Addison Wesley Publishing, Pergamon Press, Reading, MA, 1964)

    Google Scholar 

  18. Berge, B. Electrocapillarity and wetting of insulator films by water. C. R. Acad. Sci. II 317 2, 157–163 (1993)

    CAS  Google Scholar 

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

    Book  Google Scholar 

  20. Aveyard, R. et al. Measurement of long-range repulsive forces between charged particles at an oil-water interface. Phys. Rev. Lett. 88, 246102-1-4 (2002)

    Article  ADS  Google Scholar 

  21. Pusey, P. N. & van Megen, W. Phase-behaviour of concentrated suspensions of nearly hard colloidal spheres. Nature 320, 340–342 (1986)

    Article  ADS  CAS  Google Scholar 

  22. Crocker, J. C. & Grier, D. G. Methods of digital microscopy for colloidal studies. J. Colloid Interf. Sci. 179, 298–310 (1996)

    Article  ADS  CAS  Google Scholar 

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We thank B. Berge and T. M. Squires for discussions. We gratefully acknowledge support from the NSF, the Materials Research Science and Engineering Center through the auspices of the NSF and the Division of Mathematical Sciences. A.B. acknowledges the support from the Emmy Noether-Program of the DFG.

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Correspondence to D. A. Weitz.

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Nikolaides, M., Bausch, A., Hsu, M. et al. Electric-field-induced capillary attraction between like-charged particles at liquid interfaces. Nature 420, 299–301 (2002).

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