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(Reference retrieved automatically from SciELO through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Influence of acid-basic characteristic of Al2O3 or SnO2 surfaces on the stability of ceramic suspensions with commercial dispersants

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Author(s):
D. Gouvêa [1] ; B. B. S. Murad [2]
Total Authors: 2
Affiliation:
[1] Universidade de São Paulo. Escola Politécnica. Departamento de Engenharia Metalúrgica e de Materiais
[2] Universidade de São Paulo. Escola Politécnica. Departamento de Engenharia Metalúrgica e de Materiais
Total Affiliations: 2
Document type: Journal article
Source: Cerâmica; v. 47, n. 301, p. 51-56, 2001-03-00.
Abstract

A stable ceramic dispersion can be obtained by mixing a ceramic powder, a solvent and a dispersant. Polymers adsorbed to ceramic particles may stabilize the dispersions by creating a repulsion charge among then.The stabilization has an electrostatic or steric origin, or even the sum of both processes. The adsorption depends on the characteristics of the powder surface. Isoelectric points (IEP) of the SnO2 and alumina are 4 and 8, respectively. The basic/acid characteristic of the surface originates a competition between the adsorption of polymers derivated from polyacrilic acids and hidroxiles due to acidic characteristics of the SnO2 surface. In the other hand, alumina's basic surface allows polymers to adsorb and to increase the zeta potential without any competition between the dispersants and OH- ions. This study has been carried out by simultaneously measuring the pH, zeta potential temperature and conductivity of the system. ESA (Eletrokinetic Sonic Amplitude) technique was used. (AU)