Influence of kinetics on the determination of the surface reactivity of oxide suspensions by acid-base titration.
The effect of acid-base titration protocol and speed on pH measurement and surface charge calculation was studied on suspensions of gamma-alumina, hematite, goethite, and silica, whose size and porosity have been well characterized. The titration protocol has an important effect on surface charge calculation as well as on acid-base constants obtained by fitting of the titration curves. Variations of pH versus time after addition of acid or base to the suspension were interpreted as diffusion processes. Resulting apparent diffusion coefficients depend on the nature of the oxide and on its porosity.
Duc
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Université Pierre et Marie Curie-Paris 6, ENSCP, CNRS-UMR 7575, Laboratoire d'Electrochimie et de Chimie Analytique, 11, Rue Pierre et Marie Curie, 75231 Paris Cedex 05, France.
Adekola
F
F
Lefèvre
G
G
Fédoroff
M
M
D000537:Aluminum Oxide / Q000737:chemistry*; D003217:Conductometry; D005290:Ferric Compounds / Q000737:chemistry*; D058085:Iron Compounds / Q000737:chemistry*; D007700:Kinetics; D008903:Minerals; D016062:Porosity; D012822:Silicon Dioxide / Q000737:chemistry*; D013535:Suspensions
D005290:Ferric Compounds; D058085:Iron Compounds; D008903:Minerals; D013535:Suspensions; C094886:goethite; C000499:ferric oxide; D012822:Silicon Dioxide; D000537:Aluminum Oxide