Sol-gel method, applications

J. D. Protein-doped monolithic silica columns for capillary liquid chromatography prepared by the sol-gel method applications to frontal affinity chromatography. Anal Chem... 

Cardoso WS, Gushikem Y (2005) Electrocatalytic oxidation of nitrite on a carbon paste electrode modified with Co(II) porphyrin adsorbed on SiO /SnOj/phosphate prepared by the sol-gel method. J Electroanal Chem 583 300-306 Cardoso WS, Francisco MSP, Landers R, Gushikem Y (2005) Co(ll) porphyrin adsorbed on SiOj/SnOj/phosphate prepared by the sol-gel method. Application in electroreduction of dissolved dioxygen. Electrochim Acta 50 4378-4384... 

Preparation and characterization of nanocrystallines Mn-Ce-Zr mixed oxide catalysts by sol-gel method application to the complete oxidation of n-butanol... 

Sol-gel techniques have been widely used to prepare ceramic or glass materials with controlled microstructures. Applications of the sol-gel method in fabrication of high-temperature fuel cells are steadily reported. Modification of electrodes, electrolytes or electrolyte/electrode interface of the fuel cell has been also performed to produce components with improved microstructures. Recently, the sol-gel method has expanded into inorganic-organic hybrid membranes for low-temperature fuel cells. This paper presents an overview concerning current applications of sol-gel techniques in fabrication of fuel cell components. 

Table 1. Applications of sol-gel methods in fabrication of fuel cell components.

During past decades, a relatively new method attracted much of attention of experimentalists, namely, the sol-gel method widely implemented in numerous scientific and industrial applications. Actually, it caused a breakthrough in material science it is worth mentioning that sol-gel routes are cmcial for synthesis of nanomaterials, and one of methods of the 21st century namely, commercial nanoporous glasses are readily available on the market just thanks to sol-gel technologies. 

According to detailed XRD analyses, the two catalyst preparation procedures under study formed solid solutions. The application of sol-gel method led to improved selectivity to olefins in the reaction of propane ODH, compared to the simple procedure of evaporation and decomposition. However, the propane conversion on the sol-gel catalysts was lower at the same experimental conditions, while the catalysts surface area was higher. Moreover, the sol-gel samples presented higher basicity as shown by C02 TPD. It could be explained by a better incorporation of Nd into the AEO lattice, creating cationic vacancies for attaining electroneutrality and thus rendering the nearby oxide anions coordinatively unsaturated and more basic. 

The way of enzyme entrapment has been described79 proposing the application of sol-gel matrices. The optodes of urea sensor were prepared by the sol-gel method and were stored in a refrigerator. As the pH sensitive dye the bromothymol blue was used. Since it is best acting in pH range 6 to 7.6, the pH of sol-gel bulks obtained in the experiment was chosen as pH 6. Before measurements, the optodes were incubated in the temperature 36.6°C. 

Y. Tatsu, K. Yamashita, M. Yamaguchi, S. Yamamura, H. Yamammoto, and S. Yoshikawa, Entrapment of glucose oxidase in silica gel by the sol-gel method and its application to glucose sensor. Chem. Lett. 36,1615-1618 (1992). 

Photocatalysis based on TiO has attracted much attention for enviromnental cleaning and antibacterial applications [1-3], In order to synthesize TiO nanoparticles, various modification of the sol-gel method have been widely used. However, sol-gel prepared TiO requires a post-calcination process for crystallization [4], which limits the applicability of TiO coatings to temperatnre resistant substrates. On the other hand, the solvothermal method, which does not need to be followed... 

In particular, we have chosen to have a close look at the synthesis and properties of ferroelectrics and related materials, where the sol-gel method with application ofmetal alkoxide precursors seems to have produced the most promising results. In most cases we have selected for discussion in this chapter those works on the preparation of complex oxides, emphasized that the chemistry of the precursors and its role for the properties of complex oxide phases. 

Perovskites AB)/3C2/303 (A = Ba, Sr, B = Zn, Mg, Co, Ni C = Nb, Ta) are promising compounds for microwave applications. It is important to synthesize these complex oxides as pure perovskite phases because the slightest admixture of a second phase hinders drastically the dielectric properties of ceramics, which sinter only at very high temperatures (1400 to 1500°Q. The precursor chemistry resembles greatly that of BaTi03 formation by alkoxide or alkoxide-hydroxide routes. Below we summarize the 3 approaches to the synthesis of these perovskites by the sol-gel method ... 

Among the heteroleptic derivatives of special interest is the decanuclear cyclic molecule of [Fe( i-OMe)2 (C1CH2COO)]io —the iron ring with the effective diameter of 12 A. All the 10 iron atoms are situated in the same plane and connected with each other by pairs of (OMe)2-bridges [1554]. Hydrolysis of Fe(OR)3 and application in sol-gel method discussed in Chapters 9 and 10. 

Thin-film preparation can be coupled to other synthetic strategies such as sol-gel synthesis. For example, Qide et al. presented a synthesis of Ti02 thin films prepared by the sol-gel method (Qide et al., 2003). The interest in thin films of Ti02 lies in the application of these films to photocatalysis. Ti02 has been shown to be photocatalytic with respect to the oxidation of organic contaminants such as chloroform (Fujishima et al., 1999) ... 

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