Polysulfone membrane treated with NH 3 -O 2 plasma and its property

Abstract

The character of ammonia-oxygen (NH₃-O₂) plasma-treated polysulfone (PSF) membrane was studied in this work. The time effect of the plasma-treated PSF membrane was checked with energy-dispersive X-ray (EDX) detector, attenuated total reflection Fourier transform infrared (ATR-FTIR), membrane contact angle, and filtration property. EDX detector and ATR-FTIR spectra have shown that the surface oxygen content of the modified membrane increased in the form of peroxy, hydroxyl, and aromatic carboxide groups. However, nitrogen was not observed in the NH₃-O₂ plasma-treated membrane surface. The peroxy group disappeared and hydroxyl and aromatic carboxide groups were reduced 3 months later. However, the plasma-treated membrane still shown great hydrophilicity, and the contact angle decreased to 0 within 11 s despite the time effect. During the two rounds of 80 min of bovine serum albumin buffer solution filtration process, the fluxes of newly plasma-treated membrane and that of the membrane 3 months later decreased to 78 L m⁻² h⁻¹ and 54 L m⁻² h⁻¹, respectively, whereas the flux of the pristine membrane decreased to 12 L m⁻² h⁻¹.