The Effect of PCA-g-MWCNTs Loading on the Performance of PES/MWCNTs Hemodialysis Membrane

Abstract

Membrane fouling is one of the biggest obstacles towards hemodialysis treatment. In this work, multi-walled carbon nanotubes (MWCNTs) are incorporated to enhance the hydrophilicity and antifouling property of polyethersulfone (PES) hemodialysis membrane. Prior to the mixing, surface functionalisation of MWCNTs was carried out to introduce a large hyperbranched poly (citric acid) (PCA) for better dispersion. PCA-grafted (g)- MWCNTs were prepared by grafting citric acid monohydrate onto the wall of purified MWCNTs. PCA-g- MWCNTs (0 - 0.2 wt%) were then dispersed in PES and polyvinylpyrrolidone blends. The membranes were spun at 50 cm air gap, characterised in terms of morphology and hydrophilic properties before tested for pure water flux (PWF) and protein rejection using bovine serum albumin (BSA). The results revealed that, compared to the neat PES membrane, the PES/MWCNTs membranes were more hydrophilic. The highest PWF (110.4 L m^-2 h^-1) was achieved by the membrane incorporated with 0.1 wt% PCA-g-MWCNTs. Same trend was observed for protein rejection, where up to 0.1 wt% loading of PCA-g-MWCNTs, the PES/MWCNTs membrane rejected97.3 % of BSA compared to 88.2 % as obtained from the neat membrane. It was found that the PES/MWCNTs membranes possessed a greater PWF recovery ratio, proving that the membranes antifouling property was improved. The addition of PCA-g-MWCNTs in the membranes enhanced the hydrophilicity as well as the antifouling property of the PES membrane for hemodialysis application.