In-Situ Studies on Sol-Gel Systems

SAXS is best suited for thin ( 0.1 mm or less) sample materials, balancing between a minimimi atomic niunber density for low absorption and a maximum atomic niunber density for scattering contrast SAXS experiments are usually performed in transmission mode. The use of grazing incidence (GI-)SAXS geometry, discussed in more detail below, enables microstructure determination within a thin film or coating in situ on the substrate. 

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Although in situ infrared spectroscopy has been applied widely in terms of the systems studied, the reflective electrodes employed have been predominantly polished metal or graphite, and so an important advance has been the study of electrochemical processes at more representative electrodes such as Pt/Ru on carbon [107,122,157], a carbon black/polyethylene composite employed in cathodic protection systems [158] and sol-gel Ti02 electrodes [159]. Recently, Fan and coworkers [160] took this concept one step further, and reported preliminary in situ FTIR data on the electro-oxidation of humidified methanol vapor at a Pt/Ru particulate electrode deposited directly onto the Nafion membrane of a solid polymer electrolyte fuel cell that was mounted within the sample holder of a diffuse reflectance attachment. As well as features attributable to methanol, a number of bands between 2200 and 1700 cm were observed in the spectra, taken under shortoperating conditions, the importance of which has already been clearly demonstrated [107]. 

Inorganic carbohydrate hybrid systems - Limited information is available on the use of saccharides in nanostructured inorganic hybrids. Some papers describe the incorporation of nanosized clays in thermoplastic starch by exfoliation 21-22), Recently the synthesis of starch/clay superabsorbents was reported (23). Several studies concern the preparation and properties of organo-silicon derivatives and cellulose-based hybrids (24-25). Inorganic starch hybrids with electrorheological activity were prepared using in situ sol-gel synthesis... 

In a very recent study, Lou et al. prepared a thermoresponsive in situ gel system based on Pluronic F127 and Pluronic F68 and containing curcumin-loaded albumin nanoparticles. The physicochemical properties of Cur-BSA-NPs-Gel showed temperature-responsive features. Thus, this formulation, which transforms into a gel when exposed to eye temperature, may be applied as eye drops. The sol-gel transition temperature depended on the Pluronic F127 and Pluronic F68 concentrations increases in Pluronic F127 content decreased the sol-gel transition temperature of the formulation, whereas increases in Pluronic F68 increased the sol-gel transition temperature. Cur-BSA-NPs-Gel could enhance the ophthalmic bioavailability of curcumin in rabbit eyes and remarkably reduce the administration frequency compared with other suspension formulations [32]. 

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