Journal of Statistical Physics, Vol. 101, Nos. 12, 2000. p. 509-519.
When an electrolyte A diffuses into a gel containing another electrolyte B, the eventual formation of a rhythmic pattern of precipitate by the moving chemical reaction front is known as the Liesegang phenomenon. Although the Liesegang phenomenon has been studied for a century, the mechanisms responsible for these structures are still under discussion. However, recently, important theoretical progresses have been made towards a theoretical understanding of this phenomena. A critical analysis of the present state of the art as well as a discussion of some open problems is presented.