Chapter 16. Overview of Dispersants and Ionic Strength Effects in Whiteware Suspensions

  1. William M. Carty
  1. K. Rossington and
  2. W. Carty

Published Online: 26 MAR 2008

DOI: 10.1002/9780470294673.ch16

Materials & Equipment/Whitewares: Ceramic Engineering and Science Proceedings, Volume 22, Issue 2

Materials & Equipment/Whitewares: Ceramic Engineering and Science Proceedings, Volume 22, Issue 2

How to Cite

Rossington, K. and Carty, W. (2008) Overview of Dispersants and Ionic Strength Effects in Whiteware Suspensions, in Materials & Equipment/Whitewares: Ceramic Engineering and Science Proceedings, Volume 22, Issue 2 (ed W. M. Carty), John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9780470294673.ch16

Author Information

  1. Whiteware Research Center; Alfred University, Alfred, New York

Publication History

  1. Published Online: 26 MAR 2008
  2. Published Print: 1 JAN 2001

ISBN Information

Print ISBN: 9780470375723

Online ISBN: 9780470294673

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Keywords:

  • dispersants;
  • ionic strength effects;
  • whiteware suspensions;
  • dissolved inorganic salts;
  • rheology

Summary

Dispersants and dissolved inorganic salts have an immense effect on the rheology of kaolinite-based whiteware suspensions. Five sodium dispersants — Na-polyacrylic acid, Na-polymethylacrylic acid, Na-silicate, Na-carbonate, and Na-hexametaphosphate — were evaluated. The amount ofdispersant addition was normalized to the specific surface area of the batch consistent with the concept of specific adsorption. The rheology of the suspensions was measured and the suspension pH was monitored (but not adjusted). To demonstrate the effect of ionic concentration on suspension rheology, six salts were used (NaCl, MgCl, CaCl2, Na2SO4, MgSO4, and CaSO4) at three dispersant levels. The rheology results, supported by zeta-potential measurements, establish that anionic polyelectrolytes are responsible for dispersion (not Na+), and that the cations from salt additions are responsible for coagulation (not the anion, like sulfate).