Immobilizing chitosan nanoparticles in polysulfone ultrafiltration hollow fibre membranes for improving uremic toxins removal

In this study, the transport properties, and uremic toxins removal capability by polysulfone (PSF) membrane have been improved through the immobilisation of chitosan nanoparticles (CNP). Different loadings of CNP in the range of 0.1–0.5 wt% was incorporated into the polymer dope solutions to fabricate hollow fibre membranes that spun at different air-gap. The physicochemical study, pure water flux and uremic toxins analysis were employed to characterize the fabricated membranes physical and morphological characteristics. The incorporation of CNP increased PSF HFM porosity, pore size, ultrafiltration coefficient, KUF and uremic toxins clearance due to the formation of a thinner selective inner skin layer. However, the membranes spun with greater air-gap length exhibited decreased KUF and uremic toxins clearances due to increased membrane thickness and decreased porosity. The PSF membrane incorporated with 0.3 wt% CNP and spun at 50 cm air-gap demonstrated the highest KUF of 116 ml/m2.h.mmHg, BSA rejection of 91% as well as excellent uremic toxins clearances of 85%, 67% and 49% for urea, creatinine and lysozyme, respectively. These results suggested that the spinning conditions play critical roles in dictating the properties of the nanocomposite hollow fibre membrane (HFM) and the PSF/CNP HFM holds vast potential as a promising material for haemodialysis application.