Hydrotalcite
Mostrando 25-32 de 32 artigos, teses e dissertações.
-
25. ESTUDO DA INTERAÇÃO METAL-SUPORTE EM CATALISADORES DE RUTÊNIO PROMOVIDOS POR BÁRIO E CÉSIO PARA A SÍNTESE DE AMÔNIA / THE STUDY OF METAL-SUPPORT INTERACTION ON BARIUM AND CESIUM PROMOTED RUTHENIUM CATALYSTS FOR THE AMMONIA SYNTHESIS
The industrial ammonia synthesis process uses a triple promoted iron catalyst, operating at drastic temperature conditions between 673K and 973K, and high pressure (300atm). New catalysts have been studied, replacing iron, to increase NH3 production. The main advantage of Ru-based catalysts is that they are less sensitive to poisoning by ammonia than Fe-base
Publicado em: 2004
-
26. Estudo da adsorção de tensoativos aniônicos sulfonados em hidróxidos duplos lamelares / Estudo da adsorção de tensoativos aniônicos sulfonados em hidróxidos duplos lamelares
Hidróxidos duplos lamelares (HDL) ou compostos lamelares do tipo da hidrotalcita, são materiais com estrutura formada pelo empilhamento de camadas de hidróxidos mistos de cátions divalentes e trivalentes contendo ânions hidratados nos espaços entre essas camadas. Os HDL apresentam uma grande diversidade de aplicações podendo ser utilizados como catal
Publicado em: 2004
-
27. Influence of Ni content on physico-chemical characteristics of Ni, Mg, Al-Hydrotalcite like compounds
The physico-chemical properties of a series of Ni,Mg,Al-HTLC with Al/(Al+Mg+Ni) = 0.25 and low Ni/Mg ratios were studied by means of X-ray diffraction (XRD), thermogravimetric (TGA) and thermodifferential (DTA) analysis, N2 physissorption and temperature programmed reduction (TPR). The as-synthesized materials were well-crystallized, with XRD patterns typica
Materials Research. Publicado em: 2003-12
-
28. Efeito da adição de cromo em hidrotalcita MgAl sobre a distribuição de produtos na conversão catalitica de etanol
Hydrotalcite-like compounds Mgo,666(Al, Cr )0,334( OH)Z(CO3 )0,167. yHzO,were synthesized, calcined, characterized, and tested in the catalytic vapour phase conversion of ethanol. The synthesis was performed by co-precipitation and by replacing aluminium by chromium in the proportion of O, 10, 20, 50 and 100%.. AlI ofthe synthesized materiaIs showed diffiato
Publicado em: 2002
-
29. Reações de etanol sobre hidrotalcitas calcinadas
Hydrotalcite-like compounds, Mg1-xAlx(OH)2(Col")xl2.y H20, were synthesized, calcined, characterized, and tested as catalysts for the vapor phase conversion of ethanol. Two hydrotalcite-like compounds were synthesized by varying the fraction x of aluminum in the starting solutions from 0,25 to 0,33. Both materiaIs yielded X-ray diffraction pattems typical of
Publicado em: 2000
-
30. Remoção de Cr(VI) de soluções aquosas utilizando argilas anionicas tipo hidrotalcita
The present work reports Cr(VI) removal from aqueous solutions using calcined and uncalcined hydrotalcite type anionic clay. The synthesis of the hydrotalcite was done by coprecipitation of the cations Mg2+ and Al3+ in a basic solution of NaOH and Na2C03. The product was characterized by chemical, thermogravimetric and infrared analysis as well as by X-Ray d
Publicado em: 1997
-
31. Intercalation compounds of hydrotalcite-like anionic clays with anti-inflammatory agents, II: Uptake of diclofenac for a controlled release formulation
The purpose of this study was to investigate whether hydrotalcite is able to intercalate diclofenac, a nonsteroidal anti-inflammatory drug, and release it in a controlled manner. Layered Mg−Al hydrotalcite in the chloride form was used as a host, and the intercalation compound was prepared by Cl−/diclofenac anionic exchange. Drug release from the interca
Springer-Verlag.
-
32. Mucoadhesive bilayered tablets for buccal sustained release of flurbiprofen
The aim of this work was the design of sustained-release mucoadhesive bilayered tablets, using mixtures of mucoadhesive polymers and an inorganic matrix (hydrotalcite), for the topical administration of flurbiprofen in the oral cavity. The first layer, responsible for the tablet retention on the mucosa, was prepared by compression of a cellulose derivative a
Springer-Verlag.