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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.)

Rheological properties of aqueous suspensions of a ZnO varistor system

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Author(s):
S. L. M. Brito ; D. Gouvêa [2] ; R. Ganzella [3]
Total Authors: 3
Document type: Journal article
Source: Cerâmica; v. 53, n. 326, p. 169-174, 2007-06-00.
Abstract

Rheological properties of ceramic suspensions show strong dependence on pH, amount of dispersant and solid concentration. Most of the time, the suspensions are composed of different oxides and the rheological behavior tends to be more complex than the simple sum of single materials. In a previous work, the stability of ZnO-based varistor dispersion was analyzed regarding the physical-chemistry of the system. In this work, the method of rotational viscosimeter was used to evaluate the stability of ceramic suspensions of a ZnO-based varistor system containing Bi2O3, Sb2O3, Co3O4, Mn2O3, NiO, and Cr2O3. Using this stability information, it was possible to establish optimized conditions of pH and amount of dispersant 9.0 and 1.70/ mg/g, respectively. The limit of solid concentration was determined by a simple rheological model as 43.4%. The low packing value was probably due to the sharp grain size distribution of the ZnO powder which reduced the particle packing density. (AU)

FAPESP's process: 99/10798-0 - Study of intergranular phenomena in ceramic oxides
Grantee:Reginaldo Muccillo
Support Opportunities: Research Projects - Thematic Grants