SYNTHESIS AND CHARACTERIZATION OF ... - ePrints@USM

Figure 2.3. (b) Pore sizes of zeolites and ALPOs (Van der Waal and Bekkum, 1998)Figure 2.4 shows the development of zeolite structure as follows: the primarybuilding (SiO 4 ) 4- tetrahedron (Figure 2.4a) and the tetrahedral are connected throughtheir corners of shared oxygen atoms to form a wide range of small secondary buildingas in Figure 2.4b. In Figure 2.4c, a wide range of polyhedra is formed due to theinterconnection of the building units. In turn, it is connect to form the extendedframeworks of the various specific zeolite crystal structures. Figures 2.4a-d shows thestructure of zeolites, the corners of the polyhedra represent Si or Al atoms and theconnecting lines represent the shared oxygen atoms. Individual structures maycomprise only one basic unit or many of them such as mineral paulingite whichcontains five such polyhedra.13