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1.
Chem Commun (Camb) ; 49(62): 6998-7000, 2013 Aug 11.
Artículo en Inglés | MEDLINE | ID: mdl-23807550

RESUMEN

A new method to graft titania with organic groups has been developed. In contrast to common condensation based grafting methods, this method uses organometallic chemistry to bond organic groups directly at the surface. Thereby the introduction of hetero elements at the bonding interface is avoided.


Asunto(s)
Compuestos Organometálicos/química , Titanio/química , Compuestos Organometálicos/síntesis química , Propiedades de Superficie
2.
J Nanosci Nanotechnol ; 10(12): 8227-33, 2010 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-21121320

RESUMEN

In this study we report the synthesis of a series of composite nanostructures comprising LDH and TiO2 phases. The materials characterization showed that the LDH crystallites are encapsulated inside the TiO2 matrix after the anatase seeds are deposited on MgxAl-LDHs. The structure in which LDH phase is embedded into anatase matrix is unique bringing important advantages to the photocatalytic performances of the nanocomposites. The photocatalytic activity of the prepared nanocomposites was tested on the degradation of the methylene blue (MB) in aqueous solution. The photocatalytic activities of the nanocomposites were compared with commercial TiO2 nanoparticles Degussa P25. The nanocomposites exhibited superior photocatalytic activity in basic environment because the negatively charged surface of TiO2 nanoparticles at high pH attracts the positively charged methylene blue species.


Asunto(s)
Hidróxido de Aluminio/química , Colorantes/química , Hidróxido de Magnesio/química , Nanocompuestos/química , Titanio/química , Adsorción , Concentración de Iones de Hidrógeno , Azul de Metileno/química , Microscopía Electrónica de Transmisión , Procesos Fotoquímicos , Espectrometría Raman , Difracción de Rayos X
3.
Chem Commun (Camb) ; (7): 898-9, 2004 Apr 07.
Artículo en Inglés | MEDLINE | ID: mdl-15045119

RESUMEN

A post-synthesis deposition of vanadium silicalite-1 zeolite nanoparticles in the pores of SBA-15 results in a highly ordered hexagonal templated silica material with V-silicalite zeolitic plugs, giving rise to an increased crystallinity of the amorphous mesoporous walls.

4.
Biochim Biophys Acta ; 1082(3): 275-84, 1991 Apr 03.
Artículo en Inglés | MEDLINE | ID: mdl-2029547

RESUMEN

Metabolism of octadecadienoic acid isomers in weanling mice was studied by feeding fat-free diets supplemented with 2% by weight of cis-9,trans-12-octadecadienoic acid (c,t-18:2-d0), tetradeuterated trans-9,cis-12-octadecadienoic acid (t,c-18:2-d4) or dideuterated cis-9,cis-12-octadecadienoic acid (c,c-18:2-d2). Rates for conversion of c,t-18:2-d0 and c,c-18:2-d2 to c,t-20:4-d0 and c,c-20:4-d2 were identical and both were 5-times higher than conversion of t,c-18:2-d4 to t,c-20:4-d4. Accumulation of t,c-18:2-d4 in liver lipids was 2-4-times higher than for c,t-18:2-d0 or c,c-18:2-d2. The t,c-18:2 diet significantly increased with the 20:3(n-9) and total lipid concentrations in liver but not in heart, plasma or brain. The 20:3(n-9)/20:4(n-6) ratio in the liver lipids was 2-4-times higher for t,c-18:2-d4 than c,c-18:2-d2 fed mice. The position of the trans bond had a marked influence on the distribution of the various intermediate desaturation and elongation products. Intermediate metabolite data for the liver lipids indicated t,c-18:2-d4 was preferentially converted to 5c,11c,14t-20:3 ('dead end' product) rather than to t,c-20:4. Concentration of the 18:3(n-6) metabolite of c,t-18:2-d0 was about 10-times greater than the 18:3(n-6) metabolite of c,c-18:2-d2. Conversely, the concentration of the normal 20:3(n-6) metabolite from c,c-18:2-d2 was 4-times higher than the 20:3(n-6) metabolite of c,t-18:2-d0. Compared to the c,c-18:2 diet, the t,c- and c,t-18:2 diets significantly increased the total n-3, but not the total n-6 fatty acid content of heart lipids. These results illustrate that the position of the trans double-bond influences a variety of enzyme activities and the isomers differ in their physiological effects.


Asunto(s)
Ácidos Linoleicos/metabolismo , Animales , Peso Corporal , Química Encefálica , Cromatografía de Gases , Ácidos Grasos/análisis , Ácido Linoleico , Ácidos Linoleicos/sangre , Ácidos Linoleicos/química , Hígado/química , Masculino , Ratones , Miocardio/química , Estereoisomerismo
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