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Electrostatic Stabilization of Ultrafine Titania in Ethanol
Author(s) -
Widegren Johnny,
Bergström Lennart
Publication year - 2002
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/j.1151-2916.2002.tb00127.x
Subject(s) - electrokinetic phenomena , zeta potential , ionic strength , suspension (topology) , colloid , chemical engineering , ionic bonding , chemistry , salt (chemistry) , materials science , nanotechnology , nanoparticle , ion , aqueous solution , organic chemistry , mathematics , homotopy , pure mathematics , engineering
The colloidal stability of a suspension of very fine titania (TiO 2 ) powder in ethanol has been investigated. The electrokinetic behavior and stability ratios were determined as a function of operational pH and salt concentration. We show that the stability is strongly dependent on ionic strength; the TiO 2 suspensions will aggregate relatively rapidly at ionic strengths >10 −3 M , while suspensions exhibiting long‐term stability can be made at ≤10 −4 M , providing that the zeta potential of the TiO 2 particles is sufficiently high, i.e., |ζ|= 40–50 mV. Theoretical estimates of the stability based on electrostatic repulsion show a relatively good correlation with the experimental results, in particular in the acidic operational pH (pH*) range.