Structure-performance-fouling studies of polysulfone microfiltration hollow fibre membranes

Abstract

Hollow fibre microfiltration membranes were prepared by solution spinning process using polymer dope containing different amounts of polysulfone (PS), polyvinylpyrollidone (PVP) and ${\bf \textit{N}}$, ${\bf \textit{N}}$-dimethylformamide (DMF). Spinning dope having PS: PVP: DMF (w/w) of 15: 5: 80, 15: 7: 78 and 17: 8: 75 were used for spinning to obtain hollow fibres having different dimensions (outer and inner diameters) and pore characteristics. Relatively high water permeability was observed for hollow fibre membrane spun from 15 wt. % solution than 17 wt. % PS solution having the same PVP/PS ratio of 0·47. Decrease of the PVP/PS ratio to 0·33 in the dope solution of 15 wt. % PS solution produced hollow fibre membrane with lower flux. By changing the spinning parameters, fibre with different dimensions were obtained without a significant change in microstructural morphology. The flux decline due to fouling for the permeation of PEO/BSA solution was maximum for the hollow fibre membrane obtained from 15 wt. % PS solution while a steady flux with slight fouling was observed for the hollow fibre membrane obtained from 17 wt. % PS solution, when the PVP/PS ratio was 0·47.