Chemical Physics Letters, Vol.421, No.1-3, 221-226, 2006
Dynamics of a complex diffusion-precipitation-re-dissolution Liesegang pattern
A complex behavior in a Liesegang system involving the precipitates Co(OH)(2) and Ni(OH)(2) is reported. Under a special choice of initial cation concentrations (Experiment III), a sequence of three band domains: BA (thin-medium), AA (medium-medium) and CA (thick-medium) repetitions is displayed, as opposed to a traditional periodic pattern observed over a range of Co2+ and Ni2+ concentrations (Experiments I and II). The dynamics involves diffusion, precipitation and re-dissolution, and is analyzed quantitatively. Oscillations in the % Co(OH)(2) composition dominate the BA and AA regions, which later regularize into a monotonic and smooth decrease when the CA domain is reached. (c) 2006 Elsevier B.V. All rights reserved.