Difference between revisions of "Origins of surface charge"

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(Adsorption of ionic surfactants)
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== Origins of surface charge of colloids ==
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Most particles in an aqueous colloidal dispersion carry an electric charge
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There are many origins of this surface charge depending upon the nature of the particle and it's surrounding medium
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Consider the more important mechanisms 
 
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[[Charged interfaces#Topics | Back to Topics.]]
 
[[Charged interfaces#Topics | Back to Topics.]]

Revision as of 04:29, 17 November 2008

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Introduction

Origin of charge - Ionic solids

Reference
Substance PZC
Fluorapatite, Ca5(PO4)3(F, OH) pH = 6
Hydroxyapatite, Ca5(PO4)3(OH) pH = 7
Calcite, CaCO3 pH = 9.5
Fluorite, CaF2 pCa = 3
Barite (syntheitc), BaSO4 pBa = 6.7
Silver iodide, AgI pAg = 5.6
Silver chloride, AgCl pAg = 4
Silver sulphide, Ag2S pAg = 10.2

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Origin of charge for oxides

Oxide PZC Oxide PZC Oxide PZC
Ag2O 11.2 HgO 7.3 SnO2 5.6
Al2O3 9.1 La2O3 10.1 Ta2O5 2.8
BeO 10.2 MgO 12.4 ThO2 9.2
CdO 11.6 MnO2 5.3 TiO2 (rutile) 5.7
CeO2 8.1 MoO3 2 TiO2 (anatase) 6.2
CoO 10.2 Nb2O5 2.8 V2O3 8.4
Co3O4 7.4 NiO 10.2 WO3 0.4
Cr2O3 7.1 PuO2 9 Y2O3 8.9
CuO 9.3 RuO2 5.3 ZnO 9.2
Fe2O3 8.2 Sb2O5 1.9 ZrO2 7.6
Fe3O4 6.6 SiO2 2



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Adsorption of ionic surfactants

Reference
Reference



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Origins of surface charge of colloids

Most particles in an aqueous colloidal dispersion carry an electric charge There are many origins of this surface charge depending upon the nature of the particle and it's surrounding medium Consider the more important mechanisms


Back to Topics.