The Liesegang eyes phenomenon

Radially symmetric pattern formation phenomena were investigated experimentally and numerically in 2D using a new experimental arrangement in a precipitation system. We examined the dependence of the pattern structure and the evolution of the precipitation front on its curvature. Depending on the radius of the reaction medium, two types of precipitation patterns has been observed: (a) pattern with a continuously distributed precipitate and a well detectable precipitation-free domain (Liesegang eyes phenomenon); (b) pattern with a continuous precipitation zone and discrete ring formation. Results of our simulations are in a good agreement with the experimental observations.