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0-69469 Weinheim, 1995 ou3S-9648/95!o2a2-o180 $5.00+ .25/0 Adc. Muirr. 1995. 7, No. 2 $ ; VCH L+riagsgesellschafi mhH. 0-69469 Weinhrim. 1995 093S-964Xi9S~OZO2-0isl$5.00 + ,2510 Adv. Marer. 1995. 7, No. 2

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The process of incorporation of pyridine in the nanostructured tunnels of sepiolite was studied in detail, using various complementary characterization techniques, microporosimetry, thermal gravimetric analysis, FTIR, and multinuclear solid-state NMR. It is demonstrated that a remarkable nanohybrid material, SEP-PYR, is formed through the direct coordination of pyridine to the edge Mg(II) sites of the tunnels. This material is formed at temperatures above 140 °C when the sepiolite tunnels are dehydrated and the pyridine molecules are trapped in the tunnels. In a first step toward the formation of SEP-PYR, the pyridine molecules were incorporated at room temperature in the tunnels, by exposing sepiolite to pyridine vapors. The incorporated pyridine molecules are H-bound to the structural water molecules coordinated to the edge Mg(II) cations. In a second step, upon heating to 140 °C, approximately 50% of the pyridine is lost, together with most of the structural water coordinated to Mg(II). This event is accompanied by direct coordination of the remaining pyridine molecules in the tunnels to the edge Mg(II) ions of the octahedral sheets, resulting in a material with a structure similar to the parent sepiolite, but with pyridine molecules coordinated to the Mg(II) edge cations. This material is stable up to 450 °C. At this temperature, the coordinated pyridine molecules escape from the tunnels, resulting in a collapsed sepiolite structure.

Ahstrart-This contribution concerns intercalation materials based on the formation of intracrystalline polymer-salt complexes obtained by insertion of poly(ethylene oxide) (PEO) and crown-ether compounds in a layer silicate (montmorillonite), containing Na+ exchangeable cations in their interlayer space. Polyoxyethylene compounds (crown ethers and PEO) are able to associate. interlayer cations modifying dramatically the ionic conductivity of the natural silicate. The new organo-inorganic materials exhibit a two-dimensional structure able to induce an anisotropic character in their electrical properties.

El Hadad, Amir A., et al. Preparation of sol-gel hybrid materials from gammamethacryloxypropyltrimethoxysilane and tetramethyl orthosilicate: study of the hydrolysis and condensation reactions. Colloid and Polymer Science, 2011, 289(17-18) Si NMR spectroscopy. The hydrolysis of the prepared sol was also evaluated by liquid state 13 C NMR spectroscopy. The results indicated that under the adopted synthesis strategy conditions, the hydrolysis process require four hours to be completed.

Intercalated materials the electronic framework behavior of a semiconducting host lattice with the ionic‐conductivity properties of poyethyleneoxide/alkali‐metal guest species are reported. Such materials are of interest for use in solid‐state high‐energy batteries. Here, layered transition metal chalcogenides serve as the host materials, polyethyleneoxide being intercalated by two different methods.