Ultrathin Thin-Film Composite Polyamide Membranes Constructed on Hydrophilic Poly(vinyl alcohol) Decorated Support Toward Enhanced Nanofiltration Performance

Abstract

Traditional polyamide-based interfacial polymerized nanofiltration (NF) membranes exhibit upper bound features between water permeance and salt selectivity. Breaking the limits of the permeability and rejections of these composite NF membranes are highly desirable for water desalination. Herein, a high-performance NF membrane (TFC-P) was fabricated via interfacial polymerization on the poly­(vinyl alcohol) (PVA) interlayered poly­(ether sulfone) (PES) ultrafiltration support. Owing to the large surface area, great hydrophilicity, and high porosity of the PES–PVA support, a highly cross-linked polyamide separating layer was formed with a thickness of 9.6 nm, which was almost 90% thinner than that of the control membrane (TFC-C). In addition, the TFC-P possessed lower ζ-potential, smaller pore size, and greater surface area compared to that of the TFC-C, achieving an ultrahigh water permeance of 31.4 L m–2 h–1 bar–1 and a 99.4% Na2SO4 rejection. Importantly, the PVA interlayer strategy was further applied to a pilot NF production line and the fabricated membranes presented stable water flux and salt rejections as comparable to the lab-scaled membranes. The outstanding properties of the PVA-interlayered NF membranes highlight the feasibility of the fabrication method for practical applications, which provides a new avenue to develop robust polyamide-based NF desalination membranes for environmental water treatment.

Ultrapermeable nanofiltration membranes with tunable selectivity fabricated with polyaniline nanofibers

“…Fig. S14† compares the Na 2 SO 4 rejection and water permeance reported here with previous work 41–53 sorted by the materials used in the interlayer. The results indicate that the i TFC membrane with a nanofibrous PANI interlayer not only has a tunable sieving ability, but also demonstrates a superior integrated NF performance compared to the others built on polymeric, carbon, and microporous material-based interlayers.…”

Poly(vinyl alcohol)‐based membranes for fuel cell and water treatment applications: A review on recent advancements

“…Construction of interlayer is done to improve the IP reaction kinetics during the TFC membrane preparation, as well as to enhance the membrane performance. Usually, CNTs, cellulose nanomaterials, GO, nTiO 2 , polydopamine, and metal organic frameworks are prominently employed for making thin intermediate layer of TFC, in the laboratory scale, to study the membrane performance 136 . Preparation of intermediate layer, using these materials, in the practical membrane manufacturing line has not been explored yet.…”

Nanofiltration Membranes Formed through Interfacial Polymerization Involving Cycloalkane Amine Monomer and Trimesoyl Chloride Showing Some Tolerance to Chlorine during Dye Desalination

“…Strategies such as varying the monomer properties [ 13 , 14 , 15 , 16 ], embedding nanofillers [ 17 , 18 , 19 ], tailoring of the membrane support properties [ 20 , 21 ], inclusion of gutter layers [ 22 , 23 ], and surface modification [ 24 , 25 , 26 , 27 , 28 ] are widely explored to improve separation efficiency and chemical resistance. For example, Feng et al [ 29 ], used 3,5-diamino-1,2,4-triazol as an amine monomer, and reacted it with TMC to make a polyamide membrane for dye/salt separation.…”