Fabrication and characterization of novel PES-based nanocomposite hollow fiber membranes for the hemodialysis process

In the hemodialysis process, membrane filtration is used to clean blood. Urea and creatinine are two significant substances that should be removed from the blood during hemodialysis, which takes a great deal of time. To decrease the hemodialysis process time, in this study, we fabricated novel polyethersulfone nanocomposite hollow fiber membranes with silica and amine-modified silica nanoparticles via the non-solvent induced phase separation (NIPS) method. Membranes have been evaluated in a membrane contactor system by two modes of contact with fresh sweeper fluid (retentate process) and recycled sweeper fluid (circulated process) to remove urea and creatinine from a synthetic blood-like solution. Fourier transform infrared (FTIR) was carried out along with pure water flux, contact angle, mechanical strength, field emission electron microscope test (FESEM), and X-ray diffraction (EDX) to characterize the synthesized nanoparticles and fabricated membranes. The results revealed that modification of membranes by silica and amine-modified silica nanoparticles increased the urea and creatinine removal rate from the feed as the modified membranes’ separation mechanisms were adsorption and diffusion. Furthermore, removal of urea and creatinine were higher in the retentate process than the circulated process. The membrane samples containing 1.5% amine-modified silica nanoparticles had the highest urea and creatinine removal rate compared to the other modified membranes containing fewer or higher amine-modified silica and/or silica nanoparticles in the both retentate and circulated processes. The adsorption kinetics showed that the adsorption of urea and creatinine on the surface of the silica and amine-modified silica nanoparticles were consistent with the pseudo-second kinetic model, meaning rapid and possibly irreversible adsorption.