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| '''Surface conductivity''' is an additional [[Electrical resistivity and conductivity|conductivity]] of an [[electrolyte]] in the vicinity of charged surfaces.<ref>Surface and volume [[Conductivity (electrolytic)|volume conductivity]] correspond to the electrically driven motion of [[ions]] in an [[electric field]].</ref> Close to charged surfaces a layer of [[counter ion]]s of opposite polarity exists which is attracted by the [[surface charge]]s. This layer of higher ionic concentration is a part of the interfacial [[Double layer (interfacial)| double layer]]. The concentration of the ions in this layer is higher as compared to the [[Conductivity (electrolytic)|volume conductivity]] far from the charged surface and leads to a higher conductivity of this layer. | | Jayson Berryhill is how I'm known as and my spouse doesn't like it at all. Some time ago he selected to live in North Carolina and he doesn't plan on changing it. Distributing manufacturing is how he tends to make a residing. I am really fond of handwriting but I can't make it my occupation really.<br><br>my blog - clairvoyance ([http://si.dgmensa.org/xe/index.php?document_srl=48014&mid=c0102 si.dgmensa.org]) |
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| [[File:Surface Conductivity.svg|thumb|300px|]]
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| [[Marian Smoluchowski|Smoluchowski]] was the first to recognize the importance of surface conductivity at the beginning of the 20th century.<ref>M. von Smoluchowski, Physik, Z., 6, 529 (1905)</ref>
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| There is a detailed description of surface conductivity by Lyklema in "Fundamentals of Interface and Colloid Science" <ref>Lyklema, J. "Fundamentals of Interface and Colloid Science", vol. 2, Academic Press, 1995</ref>
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| The Double Layer (DL) has two regions, according to the well established Gouy-Chapman-Stern model, Ref.2. The upper level, which is in contact with the bulk fluid is the [[diffuse layer]]. The inner layer that is in contact with interface is the [[Stern layer]].
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| It is possible that the lateral motion of ions in both parts of the DL contributes to the surface conductivity.
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| The contribution of the Stern layer is less well described. It is often called "additional surface conductivity".<ref>Dukhin, S.S. and Derjaguin, B.V. "Electrokinetic Phenomena", John Wiley and Sons, New York (1974)</ref>
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| The theory of the surface conductivity of the diffuse part of the DL was developed by Bikerman.<ref>Bikerman, J.J. Z.Physik.Chem. A163, 378, 1933</ref> He derived a simple equation that links surface conductivity κ<sup>σ</sup> with the behaviour of ions at the interface. For symmetrical electrolyte and assuming identical ions diffusion coefficients D<sup>+</sup>=D<sup>-</sup>=D it is given in Ref.2:
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| :<math> {\kappa}^{\sigma} = \frac{4F^2Cz^2D(1+3m/z^2)}{RT\kappa}\left(\cosh\frac{zF\zeta}{2RT}-1\right)</math>
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| where
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| :F is the [[Faraday constant]]
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| :T is the [[absolute temperature]]
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| :R is the [[gas constant]]
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| :C is the ionic concentration in the bulk fluid
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| :z is the [[ion]] [[valence (chemistry)|valency]]
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| :ζ is the [[electrokinetic potential]]
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| The parameter ''m'' characterizes the contribution of [[electro-osmosis]] to the motion of ions within the DL:
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| :<math> m = \frac{2\varepsilon_0\varepsilon_m R^2T^2}{3\eta F^2 D}</math>
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| The [[Dukhin number]] is a dimensionless parameter that characterizes the contribution of the surface conductivity to a variety of [[electrokinetic phenomena]], such as, [[electrophoresis]] and [[electroacoustic phenomena]].
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| ==See also==
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| *[[Interface and Colloid Science]]
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| ==References==
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| {{reflist}}
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| {{DEFAULTSORT:Surface Conductivity}}
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| [[Category:Chemical mixtures]]
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| [[Category:Colloidal chemistry]]
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| [[Category:Condensed matter physics]]
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| [[Category:Matter]]
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| [[Category:Soft matter]]
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Jayson Berryhill is how I'm known as and my spouse doesn't like it at all. Some time ago he selected to live in North Carolina and he doesn't plan on changing it. Distributing manufacturing is how he tends to make a residing. I am really fond of handwriting but I can't make it my occupation really.
my blog - clairvoyance (si.dgmensa.org)