A mathematical formulation is presented of Wilhelm Ostwald’s supersaturation theory of Liesegang ring formation. The theory involves diffusion of two reactants toward one another, their chemical reaction to form a product, the reverse reaction, and diffusion of the product. When the product concentration reaches a certain supersaturation value, it begins to precipitate. It is shown that this theory can lead to recurrent precipitation, resulting in rings or bands of precipitate. Conditions under which this occurs are determined. In addition, the locations and times of formation of the bands are calculated and shown to agree with experimental results.
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© 1981 American Institute of Physics.
1981
American Institute of Physics
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