Permeability performance of different molecular weight cellulose acetate hemodialysis membrane

Abstract

Dialysis membranes were casted from solutions containing 20 wt.% celluloseacetate (CA), various concentrations of monosodium glutamate (MSG) and formic acid. Effect of MSG and differentmolecularweights of celluloseacetate on membranepermeability was investigated. As the MSG concentration increased from 2 wt.% to 6 wt.%, the uremic toxins permeability was enhanced, but further increase beyond this point did not improve the permeabilityperformance. Similar separation trend was observed regardless of the CA molecularweight used, but membranes produced form high molecularweight CA membrane exhibit better uremic toxic permeability. SEM images illustrated that MSG influences the membrane thickness and macrovoids formation, while high molecularweight CA tends to suppress the size of the macrovoids. MSG also tends to reduce the membrane resistance promoting the formation of porous structure and thus explained for high ultrafiltration rate (UFR). In order to gain more insight on the influence of both MSG and molecularweight of CA on membrane properties, the membrane surfaces were analysed using Attenuated Total Reflection Fourier Transform Infrared (ATR-FTIR), contact angle measurement (CAM), atomic force measurement (AFM). In addition, mechanical test and thermal stability studies were performed in this study to evaluate the strength of the membranes. In short, MSG and high molecularweight CA played crucial roles in enhancing the separation performance.