Composite nanofiltration (NF) membrane was developed polyacrylic acid (PAA) in situ UV graft polymerization process using ultrafiltration (UF) polysulfone (PSF) membrane as porous support. FT-IR spectra indicated that grafting was performed and it show peaks at 1,732 cm−1 and 3,396 cm−1 region for CO and OH starching bond of acrylic acid (AA) monomer, respectively. AFM microscopy showed the roughness of surface was reduced by increase of UV irradiation times. Effect of irradiation time on the grafting of acrylic acid (AA) in the same concentration was discussed. The salts rejection increase was accompanied with grafting of polysulfone (PSF) ultrafiltration (UF) membrane. The rejection of Na2SO4, MgSO4, NaCl and CaCl2 salts by PSF-grafted-PAA nanofiltration (NF) membrane was in 98, 60, 52 and 30% respectively, under 0.3 MPa.
Keywords: AFM, membrane, nanofiltration (NF), PAA, PSF, SEM