Organically modified oxide preparation

The preparation of organically modified oxide surfaces for chromatographic purposes (some of them very specific) is a very rich and productive field of research. A few examples are presented in the following sections. 

Substituting a certain part of the alkoxidic groups by nonhydrolysable ones, such as alkyl groups in the case of alkoxysilanes or phosphonic acid in the case of metal alkoxides, organically modified oxides, i.e. inorganic-organic hybrid materials, have been prepared. 

Another electro-oxidation example catalyzed by bimetallic nanoparticles was reported by D Souza and Sam-path [206]. They prepared Pd-core/Pt-shell bimetallic nanoparticles in a single step in the form of sols, gels, and monoliths, using organically modified silicates, and demonstrated electrocatalysis of ascorbic acid oxidation. Steady-state response of Pd/Pt bimetallic nanoparticles-modified glassy-carbon electrode for ascorbic acid oxidation was rather fast, of the order of a few tens of seconds, and the linearity was observed between the electric current and the concentration of ascorbic acid. 

A disadvantage of most organic modifiers is their incompatibility with the popular flame ionization detector (FID). We are presently investigating the modification of carbon dioxide with small amounts of highly oxidized, polar compounds that are invisible to the FID, such as formic acid. Our results with formic acid, at concentrations of about 0.3,0.5, and 0.7% (w/w) in CO2, may be summarized as follows (15), (Crow and Foley, manuscript in preparation) The addition of formic... 

Lim, S.K. Kim, J.W. Chin, L Kwon, Y.K. Choi, H.J. Preparation and interaction characteristics of organically modified montmorillonite nanocomposite with miscible polymer blend of poly(ethylene oxide) and poly(methyl methacrylate). Chem. Mater. 2002, 14, 1989-1994. 

Zhong and co-workers [530] described recent results of an investigation of the electrocatal3dic oxidation of methanol using carbon-supported An and Au-Pt nanoparticle catalysts. The exploration of the bimetallic composition on carbon black support was aimed at modifying the catalytic properties for the methanol oxidation reaction at the anode in direct methanol fuel cells (DMFCs). An and Au-Pt nanoparticles of 2-3 nm sizes encapsulated in an organic monolayer were prepared, assembled on carbon black materials and treated thermally. The results have revealed that these Au-Pt nanoparticles catalysts are potentially viable candidates for use in fuel cells under a number of conditions [530],... 

Oxidation is the area where organically modified surfaces have probably found most use. A wide variety of materials have been prepared, using several methods for attaching the organics to the surface, with many areas of oxidation chemistry benefiting from the materials thus derived. 

As the title indicates, this little book is devoted specifically to modified oxides and phosphates. Each chapter consists of a general and short introduction to the specific subject, followed by some examples from the literature and by a specific example, or examples this last part is organized, in some cases, with a paper structure, that is, with an experimental part and a results and discussion section. I think that this is a good choice since not only general data are presented, but specific procedures to prepare the described compounds, adding to the fundamental knowledge presented. Hence, the present book is both a review about a specific theme, and also a preparative manual. 

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