Influence of monosodium glutamate additive on the morphology and permeability characteristics of polyamide dialysis membranes

Membranes were prepared with dope solutions of various concentrations of polyamide and monosodium glutamate (MSG) additive for dialysis applications. The results show that the membranes with higher MSG concentrations had higher water uptakes and porosities. The membranes were characterized with scanning electron microscopy (SEM) and atomic force microscopy techniques and evaluated in terms of the permeability of solutes, such as urea and creatinine. The cross-sectional structure of the membranes prepared without MSG additive or with a low MSG concentration were dense, and their surfaces consisted of large-sized nodule aggregates. The permeation of solutes was less through these membranes. When the amount of additive in the membrane solution was sufficient, macrovoids were seen in the SEM images, and the sizes of nodules were small, which caused an increase in the diffusive permeability of solutes. The surfaces of the membranes with higher MSG concentrations were found to be smooth; this could be useful for the dialysis process. The contact angles of these membranes were also lower; this indicated that this additive improved the hydrophilicity of the membranes. (c) 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013