Polyzwitterions Grafted onto Polyacrylonitrile Membranes by Thiol–Ene Click Chemistry for Oil/Water Separation

Abstract

Zwitterionic poly(sulfobetaine methacrylate) (PSBMA) was successfully loaded onto a polyacrylonitrile membrane surface by thiol−ene click chemistry. The chemical composition and structure of zwitterionic membrane surfaces were analyzed by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), X-ray photoelectron spectroscopy (XPS), and energy-dispersive X-ray (EDX) analysis. An increasing amount of sulfobetaine methacrylate (SBMA) led to a higher density of grafted PSBMA chains, which increased from 0 to 776.7 μg/cm 2 . As a result, the pores of the membranes were blocked, causing a decrease in the permeation flux of the membranes. The fabricated zwitterionic structure induced superhydrophilicity, underwater superoleophobicity, and oilfouling resistance to the membrane, as confirmed by contact angle measurements of pure water and oily compounds. The zwitterionic membrane was used for the separation of several oil-in-water emulsions, exhibiting outstanding separation efficiency with more than 99.4% oil removal. The antifouling ability of zwitterionic polyacrylonitrile (PAN) membranes was examined by multicycle filtration. It is found that the reversible and irreversible fouling have been suppressed, which is associated with the recycling of the zwitterionic membrane with a high flux recovery ratio. Generally, surface zwitterionicalization via thiol−ene click chemistry proved to be suitable for the preparation of antifouling polyacrylonitrile membranes for emulsion separation.

Efficient Metal Cutting Fluid Wastewater Separation of Polyacrylonitrile Ultrafiltration Membranes Enabled by Metal Ion Cross-Linking

“…The oily wastewater purification performance of Cu 2+ @HPAN in terms of permeating flux and FRR is compared with that of the state-of-the-art polymer membranes reported in the literature. A combination of better hydrophilicity, an optimized pore structure, and a better surface ζ potential enables the separation performance of Cu 2+ @HPAN to be superior to those of all other polymer UF membranes modified through grafting, mixing, coating, interfacial polymerization, and copolymerization (Figure D). − The fabrication and separation conditions for these membranes are listed in Table S3.…”

Recent Progress in Microfiltration/Ultrafiltration Membranes for Separation of Oil and Water Emulsions

“…The zwitterionic polymer formed a stable hydration layer, and due to this, the oil droplet was easily lifted from its surface without leaving any residue. The oil‐in‐water rejection efficiency was greater than 99.4 % when the PAN‐g‐PSBMA membrane was used for filtration [178] …”

“…The oil-in-water rejection efficiency was greater than 99.4 % when the PAN-g-PSBMA membrane was used for filtration. [178] As discussed earlier, the PAN membranes are extensively explored for oil and water separation, but the low porosity, low permeances, and poor antifouling performances remain critical challenges. The electrospun nanofibrous membrane is one of the solutions to achieve high flux.…”

“…Schematics for the construction of the zwitterionic PAN membrane via thiol-ene click chemistry. Reprinted with permission from ref [178]. Copyright 2020 American Chemical Society.…”

Thiol-Ene “Click Reactions” as a Promising Approach to Polymer Materials

“…Эффективность разделения ПЭГилированной мембраны для нескольких видов эмульсий "масло в воде" достигает 99,9%, что свидетельствует об отличных характеристиках разделения. А в работе [139] полиакрилонитрильная мембрана была модифицирована цвиттерионным поли (сульфобетаинметакрилат)ом с помощью тиол-ен "клик" химии (Рисунок 11). Рисунок 11.…”