Studies on Electrokinetic Effects Across Supported Mixed Lipid Membranes

Abstract

We considered artificial mixed lipid membranes, supported by a pyrex sintered G 4 glass disc and measured the hydraulic permeability, electroosmosis, the streaming potential and current of acetone in this system. The phenomenological coefficients have been calculated by applying the formalism of non-equilibrium thermodynamics. The cross coefficients L 12 and L 2i were found nearly equal showing the validity of the Onsager reciprocal relation for the system studied. The thermodynamic fluxes and forces were found to be linearly related. The maximum of the electrokinetic energy conversion of electroosmosis and of the streaming potential has been calculated.

Electrokinetic Energy Conversion in Heterogeneous Ion-Exchange Plugs

“…s and equation (4) general it can be seen that the maximum efficiency is extremely low because the cross-phenomenological coefficient L 21 , which represents the electricalmechanical coupling, is also very small (-ºÏ" 11 m 3 /Vs), [7]. Similar results have been found with both weakly charged and ion-exchange membranes [1][2][3][4][5][6]. This implies that a large part of the input energy is dissipated in the electrokinetic processes.…”

“…Nevertheless, it is worthwile characterizing electrokinetic processes from an energy conversion point of view in order to find out which parameters influence *7max-Several papers have been published recently [1][2][3][4][5][6], analyzing the variation of ^m ax in non-equilibrium thermodynamics terms. These papers deal meanly with the effect of the permeant composition on f/ max when both weakly charged [1][2][3][4] and ion-exchange membranes [5,6] are used as porous media. But */ max depends as much on the structure of the membrane as on the permeant composition and few papers have been published dealing with the effects of these structural factors of The aim of this work, therefore, is to understand the variations in f/ max under all experimental conditions, by discovering the effect of the structural characteristics (composition, compactness and D.V.B.…”

Electrokinetic Energy Conversion in Porous Polystyrene Plugs

“…As a consequence of the increase in the viscosity in the porous plug, these processes are strongly dissipative and their maximum energy conversion efficiency (y max ) is extremely low. Several papers have been published analyzing the effect of the permeant composition on y max [2][3][4][5][6][7], but studies of the effect of the electrolyte concentration are rare in literature. An experimental investigation of the energy conversion mechanism in a streaming potential is described, involving a study of the influence of both the permeant composition and the electrolyte concentration.…”