Poly(vinylidene fluoride) with Grafted Zwitterionic Polymer Side Chains for Electrolyte-Responsive Microfiltration Membranes

Abstract

Thermally induced molecular graft copolymerization of the zwitterionic monomer, N,N′-dimethyl-(methylmethacryloyl ethyl)ammonium propanesulfonate (DMAPS), with the ozone-preactivated poly-(vinylene fluoride) (PVDF) was carried out in a mixed solvent of N-methyl-2-pyrrolidone (NMP) and dimethyl sulfoxide (DMSO). The chemical composition of the resulting PVDF with grafted DMAPS polymer (PDMAPS) side chains, or the PDMAPS-g-PVDF copolymers, was analyzed by elemental analysis. An increase in the [DMAPS]/[-CH2CF2-] molar feed ratio used for graft polymerization gave rise to an increase in the graft concentration of the DMAPS polymer in the copolymer. Microfiltration (MF) membranes were prepared from the DMSO solutions of the copolymers by phase inversion in aqueous media of different ionic strength and temperature. The surface composition and morphology of the MF membranes were investigated by X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM), respectively. The mean pore size of the membrane decreased with the increase in graft concentration of the PDMAPS-g-PVDF copolymer. However, it increased with an increase in the ionic strength of the casting bath. Due to the anti-polyelectrolyte effect, the permeability of aqueous solutions through the PDMAPS-g-PVDF MF membranes exhibited a dependence on electrolyte concentration. The flow rate was observed to decrease as the electrolyte concentration of the permeate was increased.

Zwitterionic copolymer self-assembly for fouling resistant, high flux membranes with size-based small molecule selectivity

“…They have been shown to be highly resistant to biomolecular fouling due to their high degree of hydration [32][33][34][35][36][37]. Since this discovery, many researchers have improved the fouling resistance of membranes by attaching zwitterionic groups on their surface, by post-processing existing membranes [38][39][40][41][42][43][44] or by using zwitterionic surface-segregating additives [45][46][47]. Two studies incorporated zwitterionic groups in charged hydrogel layers to boost fouling resistance [48,49].…”

A novel ultrafiltration (UF) membrane with controllable selectivity for protein separation

“…Sulfobetaine (SB) and its polymer (PSB) have been used to functionalize porous membranes due to the strong hydration and environment sensitivity [12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29]. Yang et al prepared antibiofouling polypropylene MF membrane by the surface hydrophilization with PSB [13].…”

“…Yang et al prepared antibiofouling polypropylene MF membrane by the surface hydrophilization with PSB [13]. Zhai et al observed that the permeate flux of aqueous solutions through the PSB-g-poly(vinylidene fluoride) (PVDF) MF membranes decreased as the electrolyte concentration of the permeate solution increased [14]. Zhao et al used the PSB-gcellulose membrane to purify bovine serum album (BSA) from polystyrene nanoparticles (NPs) of different sizes by altering the concentration of NaCl in the solutions [12].…”

New designed nerve conduits with a porous ionic cross-linked alginate/chitisan structure for nerve regeneration

“…The design, synthesis and development of new functional materials were studied to provide suitable materials for biomedical applications such as polyacrylate, polyester, polyurethane, polyamide, polyimide, polyester, polynorborene, polytetrafluoroethylene, polydiphenylacetylenes and polymeric resins . Also, surface modification technology was considered to change the surface microenvironment of the materials [22][23][24][25][26]. Therefore, a suitable material and fabrication process can be selected, designed and established.…”