1,2,4-Triaminobenzene-crosslinked polyamide thin-film membranes for improved flux/antifouling performance

A triamine monomer was synthesized through a reduction of 2 nitro 1, 4 m-phenylenediamine. The combination of the 1, 2, 4 triaminobenzene and m-phenylenediamine (MPD) with different ratios as an aqueous solution was applied for preparation of the new polyamide-thin film composite (PA-TFC) membranes. Chemical properties of the synthesized amine monomer were characterized by Nuclear Magnetic Resonance Spectroscopy (H NMR) and Fourier-transform infrared spectroscopy (FTIR). The prepared membranes were characterized from a variety of perspectives, chemical composition, morphology and hydmphilicity by using attenuated total reflectance infrared spectroscopy (ATR-FTIR), X-ray photoelectronic spectroscopy (XPS), contact angle analyzer, field emission scanning electron microscopy (FESEM) and atomic force microscopy (AFM). The results demonstrated that the surface of membranes has been more hydrophilic, thinner and smoother as the concentration of 1, 2, 4 triaminobenzene in aqueous solution increased. A cross flow system by the feed solution of 2000 ppm NaCl was applied to investigate the performances of the prepared PA-TFC membranes. The increase of 1, 2, 4 triaminobenzene in amine solution from 0% to 0.3% resulted in a growth of water flux of PA-TFC membrane from 33 to 55.5 L m(-2).h(-1) while the salt rejection insignificant decreased from 85.14% for PA(0) to 94.17% for PA(3), respectively.