title: A novel positively charged membrane based on polyamide thin-film composite made by cross-linking for nanofiltration.
abstract: In this paper, a novel positively charged membrane was prepared through interfacial polymerization technique between polyethyleneimine in aqueous phase and trimesoyl chloride in organic phase. Next, cross-linking of polyamide (PA) layer using ρ-xylylene dichloride (XDC) and glutaraldehyde (GA) was studied. The influences of cross-linking concentrations on the separation and permeation performance of membrane were also investigated. Membranes were characterized in terms of their chemical structure, the cross-sectional and surface morphologies, contact angles, molecular weight cut-off (MWCO) and effect of pH feed solution. The salt rejection sequence of CaCl2 >NaCl > Na2SO4 showed a positive charge at the membrane surface after cross-linking reaction. The MWCO of primary PA membrane decreased from 1,135 to 775 and 885 Da for XDC and GA, respectively. XDC membrane shows highest CaCl2 divalent cationic rejection (95.5%) and lowest water flux (21.1 L/m(2).h). This study illustrates a promising method for fabrication of positively charged membrane in cation separation.
authors.affiliation: Institute of Nanoscience and Nanotechnology, University of Kashan, Kashan, Iran E-mail: akbari@kashanu.ac.ir.
authors.forename: Ahmad
authors.initials: A
authors.lastname: Akbari
authors.affiliation: Institute of Nanoscience and Nanotechnology, University of Kashan, Kashan, Iran E-mail: akbari@kashanu.ac.ir.
authors.forename: Zahra
authors.initials: Z
authors.lastname: Fakharshakeri
authors.affiliation: Institute of Nanoscience and Nanotechnology, University of Kashan, Kashan, Iran E-mail: akbari@kashanu.ac.ir.
authors.forename: Sayed Majid
authors.initials: SM
authors.lastname: Mojallali Rostami
mesh_terms: D005374:Filtration / Q000295:instrumentation* / Q000379:methods; D008567:Membranes, Artificial; D036103:Nanotechnology / Q000295:instrumentation / Q000379:methods*; D009757:Nylons / Q000737:chemistry*; D011094:Polyethyleneimine / Q000737:chemistry; D011108:Polymers / Q000138:chemical synthesis / Q000737:chemistry*
chemical_list: D008567:Membranes, Artificial; D009757:Nylons; D011108:Polymers; D011094:Polyethyleneimine