Dispersion of aqueous nano-sized alumina suspensions using cationic polyelectrolyte

Yu Jen Shin, Chia Chi Su, Yun-Hwei Shen

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45 Citations (Scopus)


In this paper, we investigate and report the effects of a cationic polyelectrolyte, polydiallydimethylammonium chloride (PDADMAC), on the stability of nano-sized alumina (α-Al2O3) suspension. Due to the static electrical repulsion interactions, PDADMAC show significant adsorption on α-Al2O3 only at alkaline pH. Considerable amount of non-adsorbed free PDADMAC exist in α-Al2O3 suspensions dispersed by PDADMAC at acidic and neutral pH. At 1.0 wt.% PDADMAC addition, α-Al2O3 became highly positively charged (>50 mV) in the entire pH range contrast with that the stability of α-Al2O3 suspension is enhanced only over the basic pH range in the presence of anionic polyelectrolyte. Free PDADMAC electrolyte in suspension results in increasing viscosity of α-Al2O3 suspensions dispersed with PDADMAC at alkaline and neutral pH. However, non-adsorbed free PDADMAC in suspension do not contribute to viscosity increase in acidic α-Al2O3 suspensions and α-Al2O3 suspensions dispersed with PDADMAC show the best flow behavior at acidic pH.

Original languageEnglish
Pages (from-to)1964-1971
Number of pages8
JournalMaterials Research Bulletin
Issue number10
Publication statusPublished - 2006 Oct 12

All Science Journal Classification (ASJC) codes

  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering

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