The length characterizing the decrease with distance of the potential in the double layer = characteristic @
[email protected] length in the corresponding electrolyte solution = \(\kappa^{-1}\):
\[\frac{1}{\kappa } = \sqrt{\frac{\varepsilon_{\text{r}}\varepsilon_{0}RT}{F^{2}\sum _{i}c_{i}z_{i}^{2} }}\] |
(rationalized four-quantity system) |
\[\frac{1}{\kappa } = \sqrt{\frac{\varepsilon_{\text{r}}RT}{4\pi F^{2}\sum _{i}c_{i}z_{i}^{2} }}\] |
(three-quantity electrostatic system) |
where \(\varepsilon\) = static @
[email protected] = \(\varepsilon_{\text{r}}\varepsilon_{0}\), \(\varepsilon_{\text{r}}\) = relative static @
[email protected] of solution; \(\varepsilon_{0}\) = @
[email protected], \(R\) = @
[email protected], \(T\) = @
[email protected], \(F\) = @
[email protected], \(z_{\text{i}}\) = concentration of species \(i\), \(z_{\text{i}}\) = ionic charge on species \(i\).
Source: PAC, 1972,
31, 577. (
Manual of Symbols and Terminology for Physicochemical Quantities and Units, Appendix II: Definitions, Terminology and Symbols in Colloid and Surface Chemistry) on page 619 [
Terms] [
Paper]