R Version of the Kedem-Katchalsky-Peusner Equations for Liquid Interface Potentials in a Membrane System

Area of Science:

• Thermodynamics
• Membrane Science
• Physical Chemistry

Background:

• Non-equilibrium thermodynamics describes energy transport and conversion.
• Membrane systems are crucial for solute transport and energy transformation.
• Existing models require adaptation for specific membrane processes.

Purpose of the Study:

• To adapt Kedem-Katchalsky equations for binary electrolyte solutions using Peusner's network thermodynamics.
• To calculate coupling coefficients and energy fluxes in membrane transport.
• To estimate and analyze the energy conversion efficiency in membrane processes.

Main Methods:

• Transformation of Kedem-Katchalsky (K-K) equations into the R variant of Kedem-Katchalsky-Peusner (K-K-P) equations.
• Calculation of Peusner coefficients from K-K coefficients.
• Determination of coupling coefficients and energy fluxes using Peusner coefficients.
• Experimental verification using an Ultra Flo 145 Dialyser membrane with NaCl solutions.

Main Results:

• Successfully transformed K-K equations to K-K-P equations for binary electrolytes.
• Calculated Peusner coefficients and coupling coefficients for membrane transport.
• Demonstrated that energy conversion efficiency increases nonlinearly with solute concentration.
• Investigated energy fluxes as a function of ionic current density.

Conclusions:

• The adapted K-K-P model effectively describes energy conversion in membrane transport.
• Solute concentration significantly impacts the efficiency of energy conversion in membranes.
• The study provides insights into energy dynamics within membrane systems for electrolyte solutions.