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



Título del documento: Influência do pH sobre a estabilidade de suspensões de alumina estabilizadas eletroestericamente
Revue: Quimica nova
Base de datos: PERIÓDICA
Número de sistema: 000313432
ISSN: 0100-4042
Autores: 1



2
3
4
Instituciones: 1Universidade Federal da Paraiba, Departamento de Quimica, Joao Pessoa, Paraiba. Brasil
2Servico Nacional de Aprendizagem Industrial, Tijucas, Santa Catarina. Brasil
3Universidade Estadual Paulista "Julio de Mesquita Filho", Instituto de Quimica, Araraquara, Sao Paulo. Brasil
4Universidade Federal do Rio Grande do Norte, Departamento de Engenharia Mecanica, Natal, Rio Grande do Norte. Brasil
Año:
Periodo: Feb
Volumen: 30
Número: 1
Paginación: 70-74
País: Brasil
Idioma: Portugués
Tipo de documento: Artículo
Enfoque: Experimental, aplicado
Resumen en inglés 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
Disciplinas: Química
Palabras clave: Ingeniería química,
Cerámica,
Polimetilmetacrilato,
Alúmina,
pH
Keyword: Chemistry,
Chemical engineering,
Ceramics,
Polymethylmethacrylate,
Alumina,
pH
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