1994 Volume 33 Issue 4 Pages 181-185
A mathematical representation of structures of both interstratified minerals and zeolites, which are all main components constituting clays, is reviewed in the special refbrence to the connectivity of their component layers and atoms. The order-disorder arrangement of interstratified minerals can be charactehzed by one dimensional connectivity between the layers in the 1st, 2nd, 3rd, ...nth neighbor. Their relationships can be simplified in terms of the concept of Markov chain in the stochastic process, and represented on an interstratified structure diagram. Three dimensional zeolite frameworks can be characterized with a concept of concentric clusters, in which the connectivity relation between the framework T (Si, Al) atoms in the 1st, 2nd, 3rd, ...nth distance (nighbor) is realized on the number and valence of front nodes. The concept also serves for the characterization of Si, Al distribution on the framework and derivation of expected frequencies of Si, Al substituted clusters. Their frequencies against different Si/Al ratio are not continuous, but discontinuous at three points of Si/Al=1.3, 2.0 and 4.0. The points are fkirly correlated with the turning points of physical and chemical properties ever reported.
It is noteworthy that both structural characteristics are realized on the mathematical representation of the connectivity relations in the consecutive neighbors.
