Effect of Additive Polyvinylpyrrolidone (PVP) on Structure and Mechanical Strength of Polyethersulfone (PES) Membrane for Hemodialysis

The global increase in chronic kidney disease (CKD) has intensified the demand for hemodialysis therapy, which relies on semi-permeable membranes commonly fabricated from hydrophobic polymers such as polyethersulfone (PES). Although PES offers excellent mechanical strength and thermal stability, hydrophilic additives such as polyvinylpyrrolidone (PVP) are often incorporated to improve membrane hydrophilicity and biocompatibility. This study investigates the effect of PVP molecular weight (PVP-10 kDa and PVP-40 kDa) as an additive on the characteristics and performance of PES/NMP hollow fiber membranes for hemodialysis applications. To evaluate the effects of PVP, membranes were fabricated under varying solvent ratios (18/82 and 21/79 w/w) and air gap distances (19, 30, 50 cm) via dry-wet spinning phase inversion. The membranes were characterized in terms of morphology using scanning electron microscopy (SEM), mechanical properties, hydrophilicity, and dialysis performance. The results show that the optimal membrane was obtained using PVP-K10 at an 18/82 (w/w) PES/NMP ratio with a 19 cm air gap, achieving urea and creatinine clearance of 45.37% and 57.5%, respectively, and BSA rejection of 72.89%. The SEM analysis confirmed the presence of an ultrafiltration membrane-type finger-like structure. Overall, the optimized PES/PVP hollow fiber membrane exhibited low-flux ultrafiltration characteristics. These results indicate that the membrane produced has the potential to be further developed into a high-flux ultrafiltration membrane with different variables for hemodialysis applications.