Multifunctionalization of Poly(vinylidene fluoride)/Reactive Copolymer Blend Membranes for Broad Spectrum Applications

Abstract

Simultaneous immobilization and cross-linking of antifouling/low toxic polymers, e.g., poly(ethylenimine) (PEI), dextran (Dex), agarose (Agr), poly(ethylene glycol) (PEG), PEI-Dex, and PEI-PEG conjugates, and stimuli-responsive copolymers on a porous membrane surface in mild reaction conditions is desirable for the enhancement of hydrophilicity, antifouling character, cytocompatibility, and inducing stimuli-responsive behavior. Grafting to technique is required since the precursors of most of these macromolecules are not amenable to surface-initiated polymerization. In this work, we report a versatile process for the simultaneous immobilization and cross-linking of a library of macromolecules on and into the blend membrane (PVDF-blend) of poly(vinylidene fluoride) and poly(methyl methacrylate)-co-poly(chloromethylstyrene). Sequential nucleophilic substitution reaction between activated halide moieties of the copolymer and amine groups of different macromolecules readily provided series of modified membranes. These membranes exhibited antifouling property superior to that of the unmodified membrane. The effectiveness of this technique has been demonstrated by the immobilization of pH or both pH- and temperature-responsive copolymer on PVDF-blend membrane for responsive separation of poly(ethylene oxide) and bovine serum albumin. Silver nanoparticles were also anchored on the select modified membranes surfaces for the enhancement of antibiofouling property. Our approach is useful to obtain verities of functional membranes and selection of membrane for a particular application.

Modification of Polysulfone Ultrafiltration Membranes via Addition of Anionic Polyelectrolyte Based on Acrylamide and Sodium Acrylate to the Coagulation Bath to Improve Antifouling Performance in Water Treatment

“…Membrane modification techniques for hydrophilization and improvement of antifouling performance involve (1) chemical modification of membrane material, (2) blending with block-copolymers [ 13 , 14 , 15 ], hydrophilic polymers, oligomers [ 16 , 17 , 18 , 19 ] and nanoparticles [ 20 ], (3) surface segregation [ 21 ], (4) grafting [ 22 , 23 , 24 ], (5) surface coating [ 25 , 26 ], (6) nanoparticle immobilization on the selective layer surface [ 27 ] and (7) nanoparticle deposition [ 28 ].…”

Composite Anion Exchange Membranes with Antibacterial Properties for Desalination and Fluoride Ion Removal

“…In addition to F – , water contains various salts (monovalent, divalent, and trivalent) and nutrients that can produce sticky biofilms on the membrane surface, resulting in blocking or fouling of the membranes. − Therefore, the preparation of membranes with antifouling or antimicrobial properties is an important research area. There are reports on the preparation of antifouling and antimicrobial ultrafiltration (UF), thin film composite nanofiltration (TFC NF), and thin film composite reverse osmosis membranes (TFC RO) by the surface modification of a nascent membrane for water purification. − An organic fouling-resistant TFC NF membrane was prepared by reducing the density of the surface carboxylic group, which was done by the reaction between piperazine (PIP) with isophthaloyl chloride . An antifouling TFC NF membrane was also prepared by first inserting the poly­(ether sulfone) ultrafiltration membrane in a mixture of calcium bicarbonate (0.5–4 wt %) with 1 wt % PIP solution, followed by dipping this modified membrane in a 0.1 wt % tirimesoyl chloride solution for cross-linking .…”

“…An antifouling TFC NF membrane was also prepared by first inserting the poly­(ether sulfone) ultrafiltration membrane in a mixture of calcium bicarbonate (0.5–4 wt %) with 1 wt % PIP solution, followed by dipping this modified membrane in a 0.1 wt % tirimesoyl chloride solution for cross-linking . An antifouling UF membrane was prepared by the deposition of block copolymer micelle, blending poly­(vinylidene fluoride) with the amphiphilic copolymers, and final modification using polymeric tertiary amines by sequential nucleophilic substitution reaction. , An organic fouling-resistant TFC RO membrane with the antimicrobial property was prepared by in situ modification using 2 wt % polyethyleneimine followed by inserting in 1 wt % diethylenetriaminepentakis (methylphosphonic acid). The modified membrane was again dipped in different metal salts to incorporate the antibiofouling property .…”

A novel antifouling and thermally stable polysulfone ultrafiltration membranes with sulfobetaine polyimide as porogen

“…Membrane material is the main factor for determining membrane performances, such as permeability and selectivity, which gives an influence on membrane properties including morphology and hydrophilicity. Polymers including polyethersulfone (PES), 4,5 polyvinyl chloride (PVC), 6,7 polyacrylonitrile (PAN), 8‐10 polyimide (PI), 11,12 polyvinylidene fluoride (PVDF), 13‐15 and polysulfone (PSf) 16‐18 have been applied in the development of UF membranes because of their chemical stability and oxidation‐resistivity. Among these synthetic polymers, PSf is of particular interest due to its high thermal durability, and excellent mechanical strength.…”