Silicic acids, layered

The combined use of a first principles method Hke SIESTA and either empirical approaches or experimental studies can be a very fruitful approach which has already been used by several authors. For instance, Girard et al. [146] have used SIESTA type calculations in order to vaHdate a force field put forward to study the structure of zeoHtic gallophosphates. Borowski et al. [148] used a combination of experimental and theoretical techniques in order to solve the structure of the layered silicic acid H-RUB-18. The high degree of structural disorder precluded a classical structure analysis based exclusively on diffraction data. These authors used a combination of tech-... 

The present work summarizes our efforts to synthesize supergallery pillared derivatives of three general families of layered compounds. The host structures of interest include smectite clays, layered double hydroxides, and layered silicic acids. 

Wang, Z., Lan. T. and Pinnavaia,T. (1996), Hybrid organic-inorganic nanocomposites formed from an epoxy polymer and a layered silicate acid (magadiite). Chemistry of Materials, Vol. 8, pp. 2200-2204. 

Layered silicic acids Kanemite, makatite, oaosilicate, magadiite, kenyaite, and layered organo-silicates... 

FIGURE 14 Intracrystalline grafting reactions of organosilanes to the interlayer region of a layered silicic acid after treatment with DMSO or NMF molecules, which expand the silica layers. (From Ref. 93. Copyright Spinger-Verlag.)... 

Depending on the final purpose of the material, the appropriate pillar can be chosen. This flexibifity in the PILC synthesis is one of the main advantages compared to other porous substrates, such as zeofites, which have one definite pore size. The technique not only focuses on clays, but other layered structures serve as host materials as well. Examples are layered double hydroxides (anionic clays), metal(IV)- phosphates and phosphonates,layered silicic acids, etc. [4,5]. 

E. Ruiz-Hitzky and J. M. Rojo, Intracrystalline grafting on layer silicic acids. Nature, 287(1980), 28. 

Magadiite is a cationic clay of fonnula Na2Sii4C>29 nH20 belonging to the family of layered silicic acids. 

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