Chemistry of Interfaces with Special Respect to Precipitation Phenomena

The general scheme of various investigations concerning the equilibrated, more static, or dynamical, frequently nonequilibrated solid/liquid/gaseous systems was pointed out approaching to the problems of interboundary states. The schemes for steady state of the growing crystal at the boundary solid/liquid, the interferences in crystal growth; especially by aggregation of primary particles into secondary structures, the role of spacial distributions of reacting ions with concentration, and, in general, the complexi.ty of the precipitation processes and structures, were discussed. It was emphasized that with the transformations from homogeneous electrolyte solutions to heterogeneous precipitating systems the equilibrium states are very rarely met. The \u27solution aging\u27 and \u27aging of precipitates\u27 may be taken a,s demonstration of this fact. Therefore the diagrams showing the time dependency of \u27precipitation bodies\u27 may be taken as a rational approach for the characterization of the systems in question. For the interpretation of the phenomena as consisting of the formation of complexes, embryos, nuclei, direct crystal growth, and the stability/instability relationship of various entities it seems necessary to pay full attention to the different transition stages leading to the concentrational differences in the methorical layer and the solution in bulk. It is assumed that such an interplay of genotypical and phenotypical factors primarily influencing the formation of \u27new parts\u27, in the Gibbs\u27 sense, in the boundary region (methorical layer) between the solid and liquid phases is the controlling mechanism for the formation of specific structures and the resulting properties of emerging solids