Theoretical Application of Irreversible (Nonequilibrium) Thermodynamic Principles to Enhance Solute Fluxes across Nanofabricated Hemodialysis Membranes

Abstract

Objective. Nanotechnology has the potential to improve hemodialysis membrane technology. Thus, a major objective is to understand how to enhance toxic solute fluxes across these membranes. The aim of this concept building study is to review the application of irreversible thermodynamic (IT) to solute fluxes.Methods. We expanded the application of the Nernst-Planck equation to include the Kedem-Katchalsky equation, pH, membrane thickness, pore size, and electric potential as variables.Results. (1) Reducing the membrane’s thickness from 25 μm to 25 nm increased the flux of creatinine,β2-microglobulin, and tumor necrosis factor-α(TNF-α) by a thousand times but prevented completely albumin flux, (2) applying an electric potential of 50–400 mV across the membrane enhanced the flux of the respective molecules by71.167 ×10-3,38.7905 ×10-8, and0.595 ×10-13 mol/s, and (3) changing the pH from 7.35 to 7.42 altered the fluxes minimally.Conclusions. The results supported an argument to investigate the application of IT to study forces of fluxes across membranes. Reducing the membrane’s thickness—together with the application of an electrical potential—qualities achievable by nanotechnology, can enhance the removal of uremic toxins by many folds. However, changing the pH at a specific membrane thickness does not affect the flux significantly.