Influência do pH sobre a estabilidade de suspensões de alumina estabilizadas eletroestericamente

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Data

2007-02-01

Orientador

Coorientador

Pós-graduação

Curso de graduação

Título da Revista

ISSN da Revista

Título de Volume

Editor

Sociedade Brasileira de Química

Tipo

Artigo

Direito de acesso

Acesso abertoAcesso Aberto

Resumo

In this work, aqueous suspensions of aluminas with different particle sizes were evaluated. The effect of pH on the electrosteric stabilization using PMAA-NH4 (ammonium polymethacrylate) as deflocculant was studied. The amount of deflocculant was optimized and rheologic properties were determined at four different pH values. Sedimentation was also evaluated. For suspensions with pH 4, an electrostatic mechanism of stabilization was observed, probably due to a flat adsorption of PMMA- on the alumina surface, leading to a small efficiency in relation to steric stabilization. For a suspension with pH 12, the steric mechanism of stabilization prevails. Suspensions with pH 7 and 9 present a higher flocculation degree. In relation to particle size, A-1000 samples present a smaller particle size, leading to a smaller interparticle distance (IPS), making stabilization more difficult.

Descrição

Idioma

Português

Como citar

Química Nova. Sociedade Brasileira de Química, v. 30, n. 1, p. 70-74, 2007.

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