Polymeric hollow fiber (HF) mixed matrix membranes (MMMs): Mutual effect of graphene oxide (GO) and polyvinylpyrrolidone (PVP) on nano-structuration

Hollow fiber (HF) membranes were fabricated using polysulfone (PSF) and 1.0 wt% graphene oxide (GO) syn-thesized through Hummer's method. The dry-wet spinning process was employed for their preparation. The structure and properties of both unmodified PSF HF membranes and those modified with GO were characterized. This encompassed analyses using scanning electron microscopy, attenuated total reflection Fourier Transform Infrared spectroscopy, thermo-gravimetric analysis, water contact angle (WCA) measurements, as well as eval-uations of water permeability and mechanical attributes. The outcomes highlighted favorable mechanical and thermal characteristics. Moreover, the GO-modified PSF HF membranes exhibited larger surface pore sizes, along with an approximate 10% reduction in WCA and a fourfold increase in water permeability compared to the raw PSF HF membranes. Additionally, the influence of varying wt% of the pore-forming agent Polyvinylpyrrolidone (PVP) on the GO-modified PSF HF membranes was investigated. While no evidence suggests that GO can replace PVP, it is plausible to infer that this two-dimensional material complements the pore-forming agent's role by stabilizing the polymer-lean phase. This contributes to the creation of larger pores via phase separation mechanisms.