**8. Acknowledgement**

282 Advances in Crystallization Processes

Based on the analysis of experimental data in both phenomenological and mathematical way, the crystallization mechanism and the corresponding critical processes occurring during crystallization are depicted in Fig. 24. These processes are: (i) dissolution of amorphous silica and/or alumina sources, (ii) formation of alumino(silicate) gel by polycondensation reactions and the partial deposition of gel onto the surface of seed crystals, (iii) formation of growth precursor species in the gel matrix at high temperature, (iv) deposition of growth species onto the surface of seed crystals, and (v) final ordering of growth species

Fig. 24. Schematic presentation of the crystallization process of seed-induced SDA-free approach for the synthesis of sub-micrometer sized ZSM-5 zeolites. (Adopted from [50] with

In this chapter, the seed-induced, SDA-free crystallization system for the growth of sub-




With the understanding of the critical processes occurring during the crystallization of ZSM-5 zeolites, it is expected that the ZSM-5 zeolites possessing more interesting properties could be obtained by the co-ordinately variation of multi-synthesis parameters at the same time. This work will also make corresponding contributions on the rational design of ZSM-5 zeolites with desired functionalities in the domain of both materials and

alkalinity, rather than by the concentration of sodium ions at room temperature; - The crystallization mechanism of the seed-induction SDA-free approach is revealed as

the typical size-independent, linear growth process on the seed surface.

micrometer sized ZSM-5 zeolites is carried out, which clearly shows that:

to form the crystalline end products.

permission of Publisher)

amount of silicalite-1 seed crystals;

phase ZSM-5 zeolite is 0.006 ≤ A ≤ 0.010;

**7. Conclusion** 

industrial catalysis.

This work is realized in the frame of the projects: NSFC (20803010), "Chen Guang" project supported by Shanghai Municipal Education Commission and Shanghai Education Development Foundation (09CG02), 'Brain Gain' Post-Doc project (I-668-2011) supported by Croatian Science Foundation and the project 098-0982904-2953, financially supported by the Ministry of Science, Education and Sport of the Republic of Croatia.
