Competing Elementary Reactions in a Capillary - Two Reaction Fronts Moving in Opposite Directions


The behavior of two reaction fronts created in a system of two competing reactions has been investigated using the reaction between xylenol orange (XO) and chromium(III) ion in aqueous solution. Two reaction fronts have been shown to move in opposite directions, which is explained in terms of relative concentrations among three reactant species. This explanation was verified by the observation of only one reaction front for selected different relative concentrations, where both reaction fronts move in unison. As predicted by theory and confirmed by computer simulation, the position (xf) of each reaction front scales as t½, irrespective of the direction of motion.

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


  1. 1.

    L. Galfi and Z. Racz, Phys. Rev. A 38, 3151 (1988).

    CAS  Article  Google Scholar 

  2. 2.

    H. Taitelbaum, S. Havlin, J. E. Kiefer, B. Trus, and G. H. Weiss, J. Stat. Phys. 65, 873 (1991).

    Article  Google Scholar 

  3. 3.

    Y.-E. L. Koo and R. Kopelman, J. Stat. Phys. 65, 893 (1991).

    Article  Google Scholar 

  4. 4.

    S. Cornell, M. Droz, and B. Chopard, Physica A 188, 322 (1992).

    CAS  Article  Google Scholar 

  5. 5.

    B. Vilenski, S. Havlin, H. Taitelbaum, and G. H. Weiss, J. Phys. Chem. 98, 7325 (1994).

    Article  Google Scholar 

  6. 6.

    E. L. Cabarcos, C.-S. Kuo, A. Scala, and R. Bansil, Phys. Rev. Lett. 77, 2834 (1996).

    Article  Google Scholar 

  7. 7.

    J. D. Murray, Mathematical Biology, Biomathematics, Springer-Verlag, Berlin, Vol. 19 (1993).

  8. 8.

    D. Avnir and M. Kagan, Nature 307, 717 (1984).

    CAS  Article  Google Scholar 

  9. 9.

    R. E. Liesegang, Naturwiss. Wochenschr. 11, 353 (1896).

    Google Scholar 

  10. 10.

    K. F. Mueller, Science 225, 1021 (1984).

    CAS  Article  Google Scholar 

  11. 11.

    H. Taitelbaum, Y.-E. L. Koo, S. Havlin, R. Kopelman, and G. H. Weiss, Phys. Rev. A 46, 2151 (1992).

    CAS  Article  Google Scholar 

  12. 12.

    Z. Koza and H. Taitelbaum, Phys. Rev. E 54, R1040 (1996).

    CAS  Article  Google Scholar 

  13. 13.

    F. D. Snell, Photometric and Fluorometric Methods of Analysis, Wiley, New York, Part I, 1978.

    Google Scholar 

  14. 14.

    H. Stunzi, L. Spicca, F. P. Rotzinger, and W. Marty, Inorg. Chem. 28, 66 (1989).

    Article  Google Scholar 

  15. 15.

    A. Yen, A. Lin, Y.-E. L. Koo, B. Vilenski, H. Taitelbaum, and R. Kopelman, J. Phys. Chem. 101, 2819 (1997)

    CAS  Article  Google Scholar 

Download references

Author information



Corresponding author

Correspondence to Sung Hyun Park.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Park, S.H., Taitelbaum, H. & Kopelman, R. Competing Elementary Reactions in a Capillary - Two Reaction Fronts Moving in Opposite Directions. MRS Online Proceedings Library 543, 249–254 (1998).

Download citation