Resumo

ARELLANO, Sofía; GALLARDO, Tzayhrí; LOPEZ, Ma. del Socorro  e  OSORIO, Guillermo. Aplicación de los modelos de Gouy-Chapman y Stern al intercambio iónico dependiente del pH de arcillas pilareadas de aluminio. Rev. Soc. Quím. Méx [online]. 2002, vol.46, n.2, pp.120-124. ISSN 0583-7693.

The pH-dependent ion exchange properties of an alumina pillared clay (Al-PILC) and its structural stability at extreme pH's, were studied. Results indicated that Al-PILC treated at 400, 500 y 600 °C was stable in the pH range of 2.5-11.5, out of this range a loss in the pillared structure was observed, as demonstrated by X-ray. The pH-dependent ion exchange capacity of these materials were mainly anionic. Acid-base titration of the Al-PILC treated at different temperatures, produced values for the zero point of charge (ZPC) in the range of 4.5-6.4, increasing with temperature treatment, which could be due to the transformation of hydroxy aluminum pillars into the corresponding oxidic forms. The average values for the pH-dependent charge of Al-PILC at 400 °C, calculated by the double layer theories of Gouy-Chapman and Stern, were found to be in good agreement with the experimental results.

Palavras-chave : Alumina pillared clays; Al-PILC; pH-dependent ion exchange.

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