Abstract
pH stable nanofiltration membranes are highly desirable in treating acidic and alkali effluents and recovering the valuable byproducts. Efforts have been devoted to preparing nanofiltration membranes with good acid/alkali resistance but the separation performance is still to be improved. Poly(amine-urea) nanofiltration membranes with excellent rejection performances were prepared by the interfacial polymerization between polyethyleneimine with the mixed organic monomer of cyanuric chloride and 1, 4-phenylene diisocyanate. In comparison with pure polyamine and polyurea membranes, the optimal poly(amine-urea) membranes exhibit simultaneously improved membrane permeability and salt rejection, > 99% for MgSO4. The membrane morphology, pore structure and chemical properties of the membranes were thoroughly characterized, demonstrating that the poly(amine-urea) selective layer is thinner and denser compared with the polyamine/polyurea prepared with a single organic monomer. The underlying mechanisms for the synergistic effect between cyanuric chloride and 1, 4-phenylene diisocyanate were revealed. In addition, the poly(amine-urea) nanofiltration membranes maintain a high rejection for MgSO4, >96%, after exposure to 20 wt% HCl and 20 wt% NaOH aqueous solutions for 150 days, demonstrating excellent acid/alkali stability.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
