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Efficient dispersants for the dispersion of gallium zinc oxide nanopowder in aqueous suspensions
Author(s) -
Li ChiaChen,
Liu WeiI,
Chen YenShin
Publication year - 2017
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/jace.14640
Subject(s) - dispersant , polyelectrolyte , dispersion (optics) , materials science , polyethylenimine , chemical engineering , aqueous solution , dispersion stability , zeta potential , cationic polymerization , steric effects , zinc , inorganic chemistry , polymer chemistry , chemistry , polymer , nanoparticle , nanotechnology , organic chemistry , composite material , transfection , biochemistry , physics , metallurgy , optics , gene , engineering
Abstract Appropriate dispersants for the dispersion of gallium zinc oxide ( GZO ) nanopowder in aqueous suspensions were identified in this study. The dispersion efficiencies and stabilization mechanisms of water‐based dispersants ammonium poly(acrylic acid) ( PAA – NH 4 ), an anionic polyelectrolyte, and polyethylenimine ( PEI ), a cationic polyelectrolyte, were compared. The experimental analyses of rheology and sedimentation showed that both PAA – NH 4 and PEI were good dispersants for the dispersion of GZO . Theoretical calculations based on Derjaguin‐Landau‐Verwey‐Overbeek theory revealed that the stabilization mechanism of PEI was mainly related to the steric effect, and a very low molecular weight of 1800 g/mol was insufficient for powder stabilization. GZO was well dispersed by PEI with high molecular weight of 10 000 g/mol, but agglomeration occurred when too much PEI was added. Compared with PEI , PAA – NH 4 was more efficient because of its high contribution to the increase in electrostatic repulsion. Based on theoretical considerations on both steric and electrostatic effects, namely, the electrosteric stabilization mechanism, PAA – NH 4 is optimal for the dispersion of GZO nanopowder in aqueous suspensions.