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We have pointed out that zinc based particles obtained from ethanolic solution of a zinc acetate derivative (zinc oxy-acetate, Zn 4 O(Ac) 6 ) are a mixture of nanometer sized ZnO, zinc oxy-acetate, and zinc hydroxide double salt (Zn-HDS). The knowledge of the mechanisms involved in the formation of ZnO and Zn-HDS phases, and the evolution of Zn species in reaction medium was monitored in situ during 14 h by simultaneous measurements of UV-vis absorption and extended X-ray absorption fine structures (EXAFS) spectra. This spectroscopic monitoring was initialized just after the addition of an ethanolic lithium hydroxide solution ([LiOH]/[Zn] ) 0.1) to the reaction medium kept under controlled temperature (40°C). This study points out the first direct evidence of the reaction between ZnO nanoparticles and unreacted zinc oxy-acetate to form a Zn-HDS phase. The dissolution of ZnO and the reprecipitation of Zn-HDS are induced by the gradual release of water mainly produced by ethanol esterification well evidenced by gas chromatography coupled to mass spectroscopy and FT-IR measurements.

The ability of assembling inorganic, organic, and even bioactive components in a single material unfolds an exciting direction in the development of novel multifunctional hybrid materials. Recently, we have observed that the hydrophilic/hydrophobic character of the organic polymeric moieties determines the swelling/diffusion control of the drug release. In this work, the antitumor cisplatin (CisPt) molecules incorporated into the ureasil-PEO (poly(ethylene oxide)) hybrid material was used as a probe for the in situ and simultaneous UV-vis and Raman spectroscopies monitoring of the kinetics of both the water uptake as well as the CisPt release by the hybrid matrix. Drug molecules were incorporated during the hydrolysis and polycondensation steps. The monolithic xerogel were analyzed by X-ray absorption spectroscopy and differential scanning calorimetry, while the drug release properties were monitored by Raman as well as UV-vis spectroscopies. The results show that the molecular structure of the CisPt is preserved in the one pot sol-gel route used in synthesizing the CisPt-loaded PEO1900 hybrid. The in situ monitoring of water uptake clearly points out the key contribution of the osmotic flow on the stepped profile of the CisPt delivered from the PEO1900 hybrid matrix.

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The TeO 2 -rich part of the TeO 2 -Nb 2 O 5 system has been investigated by temperature programmed X-ray diffraction and differential scanning calorimetry. Three invariant equilibria have been observed: one eutectic reaction (8 mol% NbO 2.5 , T E =690±5 °C, L E = TeO 2 +Nb 2 Te 4 O 13 ), one peritectic reaction (incongruent melting, at 766±5 °C, of the Nb 2 Te 4 O 13 compound) and one congruent melting reaction (congruent melting, at 810±5 °C, of the Nb 2 Te 3 O 11 compound ). A large glass-forming domain has been evidenced (0 to 25 mol% NbO 2.5). The thermal behaviour of these glasses has been followed. The glass transition, crystallization temperatures and the nature of crystalline phases formed have been determined.