TITLE:
The Behavior of Zeta Potential of Silica Suspensions
AUTHORS:
José Antonio Alves Júnior, João Baptista Baldo
KEYWORDS:
Silica Slurries, Zeta Potential, Stabilization, Iso-Electronic Point, Silica
JOURNAL NAME:
New Journal of Glass and Ceramics,
Vol.4 No.2,
April
28,
2014
ABSTRACT: Zeta potential is one of the most relevant parameters controlling the
rheological behavior of ceramic suspensions. In this work, it was observed that
for pH values below the isoelectric point (IEP), the positive value of zeta
potential of water suspensions of α-quartz
and α-cristobalite, experiences a
sudden steep increase with the increase in specific surface area of the
powders. For pH values above the IEP, the zeta potential values of crystalline
forms of silica (α-quartz and α-cristobalite), get gradually more
negative with the increase in pH. Conversely in the case of vitreous silica,
for pH values above 6, there occurs a steep change towards more negative values
of zeta potential than those presented by quartz and cristobalite. These
findings have not yet been accounted for in the DLVO theory but may provide
subsidies for better understanding of how to stabilize and destabilize
crystalline and vitreous silica water suspensions.