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Deposition of colloidal hematite onto mercury from water-ethanol mixtures

The adherence of hematite (aFe2O3) particles onto mercury electrodes in water-ethanol mixtures has been studied by counting using optical microscope images. The number of attached particles, when the ethanol content is small, decreases as the ethanol concentration increases. At a mole fraction of ethanol near to 0.2, the number of particles goes through a minimum and then it increases with ethanol concentration. When the electrode potential is modified, curves of the number of particles vs. ethanol mole fraction with the same shape are found, but which cross each other. The dependence on the ethanol concentration can be explained based on the dependence of particle/solution and metal/solution interaction energies with the solvent composition.

hematite adhesion; metal surface; water-ethanol mixtures


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