...Bernd Marler; Hermann Gies Abstract In the search for new synthesis routes of zeolites, the topotactic condensation of hydrous layer silicates shows promising results in generating novel zeolite materials with distinct framework types which might have new, interesting properties as, e.g...

... as parent materials to synthesize mesoporous and microporous framework materials by either expanding the structures using appropriate methods or by condensing the silicate layers topotactically ( Marler and Gies 2012 ). Sirinakorn et al. (2018) and Roth et al. (2016) published review articles...

.... Between these neutral layers are free water molecules, eight per unit cell, bonded to the layers by H bonds. Switzerite tranforms to metaswitzerite by expulsion of ¾ of the free water molecules and condensation of the neutral layers along c into a framework structure. Only minor changes occur within...

... ( Kooli et al. , 2001b ). The PLS-1 precursor exhibited greater thermal stability and was transformed to another CDS-1 (Cylindrically Double Saw Edge Zeolite) phase after calcination at 400°C and above, due to the topotactic dehydration-condensation between the silicate layers of PLS-1. The magadiites...

... diffraction (TEM-SAED) analyses of the reactant/product textural relationship show that the thermal decomposition of Iceland spar single crystals according to the reaction CaCO 3(s) → CaO (s) + CO 2(g) is pseudomorphic and topotactic. This reaction begins with the formation of a mesoporous structure made up...

...) of the metastable (Ca,Mg)O precursor. High ion diffusivity at T > 500 °C (ex situ experiments) favors the formation of pure CaO and MgO crystals during coarsening via oriented aggregation and sintering. These results show that the thermal decomposition of dolomite is topotactic and independent of p CO 2...

... of orientation distribution functions (ODF), normalized pole figures, and misorientation characteristics are performed with the MTEX-software on these condensed grain data files. Because, the information about the grain boundaries is lost in these files only Voronoi polygons linked to the grain centroid...

... in the original TO layer before condensation of a second tetrahedral sheet occurs to complete the formation of the illite/muscovite TOT layers. © 2009, The Clay Minerals Society 2009 Figure 1. XRD patterns of kaolinite before and after hydrothermal treatment in KOH solution at increasing reaction times...

... (HRTEM) data from these grains to show that diamond formed via a reconstructive, topotactic rather than martensitic mechanism. Electron diffraction and HRTEM images show the following three-dimensional crystallographic relationships between the interstratified graphite and diamond: (001) g ||(111) d...

... for the acicular morphology, are linked together only through hydrogen bonds, which account for the marked flexibility. Accordingly, the MoO 6 layers in molybdite can be considered a condensation product of the raydemarkite chains ( Böschen & Krebs 1974 ). Fig. 6. The crystal structure of raydemarkite...

... of the condensed starting material as soluble compounds in halide form, thus directly involving the aqueous fluid phase as a component donor. Some chemical systems, especially those involving alkalis, do not exhibit significant evidence for polysomatic reactions during synthesis. Thus these reaction paths have...

... and in the shrinkage pores of dehydrated halloysite tubes. The topotactic relationship of b * halloysite // b * kaolinite was kept between the substrate halloysite and the product kaolinite in the incipient growing stages of kaolinite. As a consequence, early formed halloysite transforms to kaolinite...

... of the complex modules results in the condensation of the wollastonite-like chains into double chains. In the resulting framework, structural cavities occur, hosting “zeolitic” water molecules and in some cases cations (usually calcium, with minor amounts of alkaline metals). “Tobermorite 11 Å” shows two...

... ( Fig. 10 ). Sapphires also contain crystalline inclusions resulted from corundum solid solution breakdown (topotactic inclusions). Fig. 9. Mineral inclusions in the Dak Nong placer sapphire. a , Topotactic inclusions of Al-hematite and other Fe-Ti oxides; b , inclusion of zircon-columbite...

...., Zhao, Y., Cui, Q., and Zou, G. ( 1990 ) High-pressure Raman studies of graphite and ferric chloride-graphite. Journal of Physics: Condensed Matter , 2 , 8083 –8088. Mitra, S.S., Brafman, O., Daniels, W.B., and Crawford, R.K. ( 1969 ) Pressure-induced phonon frequency shifts measured by Raman...

... in the dehydrated material is 37.5–50%. The decomposition product is composed of numerous, tiny MgO crystallites and voids. Electron diffraction reveals a topotactic relationship between brucite and MgO with [0001] Bru // [111] MgO and [112̄0] Bru // [11̄0] MgO . Since the porosity of the dehydrated material...

... a to c 5 . The topotactic relationship between these two structures is evident from the map of observed electron densities ( Fig. 3 ). Fig. 3. The F obs electron-density distribution maps for the single-crystal specimens calculated in Jana2006 ( Petriček et al ., 2006 ) of ( a ) ppv...

... 612–708 °C was 221 and 255 kJ/mol for lizardite and antigorite, respectively. The reaction sequences of chrysotile, lizardite, and antigorite leading to the formation of stable high-temperature products (i.e., forsterite and enstatite) are described taking into account previous topotactic...

... in a Hitachi S2500 scanning electron microscope (SEM) equipped with a Kevex energy dispersive X-ray analyzer. Samples were examined by using secondary electrons. The contrast of the secondary-electron images of the flat surface of the thin sections was optimized by using a large condenser-lens aperture...