Original scientific paper

Experimental Electrokinetic Systems and the Point Charge Double Layer Model

Mirko Mirnik ; Laboratory of Physical Chemistry, Faculty od Science, University of Zagreb, Zagreb, Croatia

Abstract

The Coulombs, 'Pc ionic cloud, and the average 1,DHp potentials of the Debye-Hückel theory, in the space adjacent to spherical particles, charged with a given number of elementary point charges, can be calculated using the equations
+fl +p
V'Cp = (1/2 rmax 7t) X X 1 / r (Al)
-n -p +n +p
‘/'DHp = - (1/2 rmax n) X X e"'7r (A2)
-n -p -m +p
^icp = (1/2 r max S (1 — G ) / r (A3)
-n -p
The Gouy-Chapman potential, ^cch P^nar surfaces is defined by
^GCh = e~x (A4)
'Pcp = 'P’cJKf/o’lf'o = 2 e0 K/4 Jt £■ The intersections of the '/yCpx = var., re, p, y, z = 0) plots with the ¥,icp(x-^0) = 1 horizontal line define x = l/xp, which is valid for given particles and ionic strength. The calculations prove that V,icp is higher than f'cch- Consequently, the introduction of the slipping Here: r = [x2 + Zic2 [(re + y)2 + ip + z)2]}05, rmax = lic remax <2 = ^ic pmax -fi, the latter being predetermined; re, p integers. The intercharge distance is /ic; x, lic in + y), lìc (p + z) are the coordinates of any point in the layer, while 0 < y, z < 1. The distance of points on the axes from the surface is x. All symbols are multiples of K, i.e., x = X'K, y = yV, z = Z’K, lic V^K

Keywords

Hrčak ID:

136771

URI

https://hrcak.srce.hr/136771

Publication date:

1.12.1994.

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