On the nucleation and crystallization of silicalite-1 from a dilute clear sol

Zeolite growth by synergy between solution-mediated and solid-phase transformations

“…The driving force for this socalled Ostwald ripening process is based on the increasing stability of particles with size, and results in the growth of larger, more stable particles at the dissolution of smaller, less stable particles. 5,6 In contrast, recent progress in understanding the zeolite growth has suggested that the nucleation occurs from the amorphous precursor phase, both in clear solutions [7][8][9][10][11][12][13][14][15] and in hydrogel systems [16][17][18][19][20][21][22] and the crystal growth mainly fall into one of the four categories: (i) addition of nanoparticles or of monomeric or oligomeric nutrients provided by the dissolution of colloidally stable precursor nanoparticles to a growing crystal, 12,[21][22][23][24][25] (ii) crystalline transformation with or without the crystal aggregation, leading to intergrowth or single zeolite crystals, [7][8][9][10][11][17][18][19][20] (iii) aggregation of crystalline building units [26][27][28][29][30] or of non-crystalline nanoparticles, [12][13][14][15] or (iv) self-assembly of small fragments around...…”

Observing a Zeolite Nucleus (Subcrystal) with a Uniform Framework Structure and Its Oriented Attachment without Single‐Molecule Addition

“…[6] Meanwhile,s inglemolecule condensation growth described in classical models is proved to be subordinate one,e xcept in the final stage of structural perfection. This combined non-classical and classical theory can satisfactorily explain certain phenomena of zeolite formation, such as nucleation, [7] crystal size jump growth, [8] two-dimensional surface growth, [9] intergrowth structure [10] and finned or branched morphology. [11] However, this also means the difficulty in observing unitary nanoparticle attachment or single-molecule condensation growth as well as acquainting us with their respective effects on the zeolite synthesis.…”

Growth of fractal aggregates during template directed SAPO-34 zeolite formation

“…The benefits of using a dendrimer nano-template for the nanoparticles formation process in zeolite syntheses rely mainly on the possibility to choice size and composition of the core substrate as well as spatial distribution of the terminal groups [20][21][22]. The finding of our results gives novel insights in current scientific interests concerning new protocols for the synthesis and the development of organic-inorganic nanostructured materials based on mesoporous frameworks with new characteristics and properties [38][39][40][41][42][43][44][45]. For example the creation of a thin porous layer around a dendrimer can introduce a mesoporous selective barrier which may be used to promote selective reactions and incorporation of key features of selected components (such as enzymes or metal complexes).…”