Amphiphilic ABA‐type triblock copolymers for the development of high‐performance poly(vinylidene fluoride)/poly(vinyl pyrrolidone) blend ultrafiltration membranes for oil separation

Abstract

ABA‐type amphiphilic triblock copolymers (TBCs) were synthesized by a reversible addition fragmentation chain transfer (RAFT) process with a telechelic polystyrene macro‐RAFT agent and 4‐[n‐(acryloyloxy)alkyloxy]benzoic acid monomers. Ultrafiltration (UF) membranes were fabricated by a phase‐inversion process with blends of the TBC, poly(vinylidene fluoride) (PVDF), and poly(vinyl pyrrolidone) (PVP) in dimethylformamide. The UF‐fabricated membranes were characterized by scanning electron microscopy, atomic force microscopy, water contact angle measurement, thermogravimetric analysis, and differential scanning calorimetry. Pure water permeation, molecular weight cutoff values obtained by the permeation of different molecular weight polymers as probe solutes, bovine serum albumin (BSA) solution permeate flux, and oil–water emulsion filtration tests were used to evaluate the separation characteristics of the fabricated membranes. The tripolymer blend membranes exhibited a higher flux recovery ratio (FRR) after the membrane was washed with sodium lauryl sulfate (0.05 wt %) solution for a BSA solution (FRR = 88%) and oil–water emulsion (FRR = 95%) feeds when than the PVDF–PVP blend membrane (57 and 80% FRR values for the BSA solution and oil–water emulsion, respectively). The pendant carboxylic acid functional moieties in this ABA‐type TBC have potential advantages in the fabrication of high‐performance membranes. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45132.

Improvement in antifouling and separation performance of PVDF hybrid membrane by incorporation of room‐temperature ionic liquids grafted halloysite nanotubes for oil–water separation

“…These new peaks indicated that the newly synthesized IL had been grafted onto raw HNTs successfully. In Figure (b), the attenuated total reflection‐FTIR spectra of all the PVDF membranes showed CH 2 wagging, CH 2 rocking, and CF stretching vibrations centered at 1404, 877, and 838 cm −1 , respectively . In addition, the band at 3132 cm −1 of M‐ILHNTs‐1.0 was attributed to the stretching vibration of CH in imidazole ring, which was consistent with the imidazole peak in Figure (a).…”

“…As shown in Figure , the WCA decreased evidently from nearly 75° for M‐0 to 57° for M‐ILHNTs‐3.0. The enhancement of membrane hydrophilicity could be explained by the migration of ILHNTs to membrane surface in phase inversion process, which would affect the separation and antifouling performance of membranes.…”

Monobromination of α,ω‐Diols: Highly Efficient Preparation of Synthetic Intermediates

“…A wildly employed synthetic pathway to prepare brominated alcohols from α , ω ‐diols, which then may be used as intermediates in other reactions, such as the production of polymers, antineoplastic drugs and lepidopteran pheromones, involves a substitution reaction of a diol in acidic medium (Scheme ), in an organic solvent.…”

Ultrafiltration membranes based on hybrids of an amphiphilic graft copolymer and titanium isopropoxide

“…Ultrafiltration (UF) membranes have been wildly applied for the separation of pure water from substances such as oils, wastewater, proteins, and nanoparticles . An attractive feature of the use of UF membranes is that much less energy is required than that required for distillation, which involves boiling the water to be purified.…”

“…Extensive research has focused on improving the hydrophilicity, adjusting the pore size, and increasing the porosity using block copolymers, surface modification, random copolymers, polymer blending, and various methods such as applying water‐pressure or phase inversion . Graft copolymers are considered attractive alternatives to block copolymers owing to their low cost, ease of synthesis, and potential to easily provide high molecular weights (>100,000 g mol −1 ) …”