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ABSTRACT A braid-reinforced hollow fiber membrane with mechanically stable coating layer was prepared by coating a blended polymer dope solution on an alkaline-treated poly(ethylene terephthalate) (PET) braid. The alkaline treatment was carried out to endow the PET braid surface with more polar groups and better hydrophilicity. The results showed that the bonding strength between the hydrophilic coating layer and modified PET braid was about two times as great as that between the coating layer and original PET braid, while the pure water permeability (PWP) of the membrane remained unchanged when the PET braid was simply treated in 3 wt % potassium hydroxide (KOH) solution at 90 °C for 1 h or 1 wt % KOH solution for 6 h. The proposed modification approach proved to be a facile, low-cost, and effective method to improve bonding strength between the coating layer and the braid, while other properties, such as PWP and morphology of the coating layer, of the braid-reinforced hollow fiber membranes were not altered, indicating promising potential in membrane engineering. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46104 [ABSTRACT FROM AUTHOR]

ABSTRACT Fluorinated acrylate emulsions have been extensively applied for hydrophobic surface coatings. To obtain fluorinated emulsions of low surface energy, amphiphilic sulfonyl macro emulsifiers consisting of 2-(perfluorohexyl) ethyl acrylate (PFHEA) and 2-acrylanmido-2-methylpropanesulfonic acid (AMPS) were designed via radical polymerization and subsequently used for the emulsion copolymerization of PFHEA, methyl methacrylate (MMA), and methyl butyl acrylate (MBA). Under optimum synthesis conditions, the emulsifier displayed superior emulsification properties such as high monomer conversion, small particle size, and excellent stability compared with conventional emulsifiers. The corresponding emulsions with sulfonyl macro emulsifiers exhibited extreme low surface energy (9.8 mN/m) and outstanding hydrophobicity due to high contents of fluorinated chains, as well as thimbleful hydrophilic sulfonyl groups, which shows the great potential in water repellent modification application. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44921. [ABSTRACT FROM AUTHOR]

ABSTRACT To improve the antifouling property of poly(vinyl chloride) (PVC) membranes, a series of poly(methacrylic acid) grafted PVC copolymers (PVC -g-PMAA) with different grafting degree were synthesized via one-step atom transfer radical polymerization process utilizing the labile chlorines on PVC backbones followed by one-step hydrolysis reaction. PVC/PVC -g-PMAA blend membranes with different grafting degree and copolymer content were prepared by nonsolvent induced phase separation method. The surface chemical composition, surface charge, membrane structures, wettability, permeability, separation performances and the fouling resistance of blend membranes were carefully investigated. The results indicated that the PMAA chains were segregated towards the surface and the membranes were endowed with negative charge. The hydrophilicity and permeability of the blend membranes were obviously improved. Furthermore, the antifouling ability especially at neutral or alkaline environments was also significantly increased. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42745. [ABSTRACT FROM AUTHOR]

ABSTRACT To effectively improve the affinity of polyethylene (PE) separators with liquid electrolyte without causing a serious pore blockage and to develop a more suitable technology for the industrial production process, porous polyvinylidene fluoride (PVDF) layer-coated PE separators are prepared by the dip-coating method followed by a dry-cast process. Different from previous investigations, a less volatile solvent and a relatively volatile nonsolvent are used to yield a preferable pore structure. A brief introduction on the pore formation mechanism during the dry-cast process is provided. The pore structure of coating layer is found to be successfully controlled by changing evaporation temperature, nonsolvent content, and PVDF concentration. The porous PVDF coating layer-modified separators show better affinity with liquid electrolyte and thermal stability. Especially, the ionic conductivity of the modified separator/liquid electrolyte system with a suitable porous coating layer on the separator could reach two times as that of PE separator/liquid electrolyte system, and the cell assembled with modified PE separator shows better cycle performances. This modification process is proved to be a facile, controllable, and effective method for PE separator modification. Meanwhile, this work could provide some theoretical and technical guidance for the production process. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 41036. [ABSTRACT FROM AUTHOR]

ABSTRACT The blending of a block copolymer into the membrane matrix is a convenient and efficient way to modify membranes. In this study, high-density polyethylene/polyethylene- b-poly(ethylene glycol) (PEG) membranes were prepared via a thermally induced phase separation process, and the extractant effect was investigated. An interesting finding was that the nonpolar extractant ( n-hexane) was more conducive to the surface enrichment of the PEG chains than the polar solvent (ethanol). The reason was deemed to be the combined effect of the entropy drive, interfacial energy, and swelling behavior. In addition, the membrane performance related to the surface chemical properties was studied. The results suggest that the prepared blend membranes extracted by n-hexane showed enhanced the hydrophilicity, antifouling properties, and water flux. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 3816-3824, 2013 [ABSTRACT FROM AUTHOR]

ABSTRACT Blending the block copolymer into the membrane matrix is a convenient and efficient way for membrane modification. In this study, HDPE/PE- b-PEG membranes were prepared via TIPS process, and the extractant effect was investigated. An interesting finding was that a non-polar extractant ( n-hexane) was more conducive to the surface enrichment of PEG chains than a polar solvent (ethanol). The reason was deemed to be the combined effect of entropy drive, interfacial energy, and the swelling behavior. Besides, membrane performances related to the surface chemical properties were studied. Results suggested that the prepared blend membranes extracted by n-hexane showed enhanced hydrophilicity, anti-fouling property and water flux. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 2680-2687, 2013 [ABSTRACT FROM AUTHOR]

Composite ultrafiltration membranes were successfully fabricated by blending a nonionic surfactant and inorganic nanoparticles via a nonsolvent‐induced phase separation (NIPS) method. Brij35 was used as the nonionic surfactant and silica (SiO2) nanoparticles from rice husk ash, a low cost and widely available material, were used as the inorganic nanoparticles. The synergetic effect of both additives was used to tailor the membrane structure and properties because the selected additives showed completely different or, in some cases, the opposite effect on the membrane properties and structure. The combined effects of Brij and SiO2 resulted in a membrane with a noticeable improvement in membrane overall performance including pure water permeability, hydrophilicity, antifouling properties, long‐term stability, tensile strength, on the cost of a slight decrease in membrane elongation. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47737. [ABSTRACT FROM AUTHOR]

We modified poly(vinylidene fluoride) (PVDF) membranes with a polydopamine (PDA) coating for photocatalytic membrane reactor application with appropriate UV resistance and studied the effects of the PDA coating conditions (i.e., coating time and dopamine concentration) and UV irradiation time on the modified PVDF membrane properties. The PVDF membrane that was surface‐coated with the appropriate dopamine solution concentration and coating time played a key role in controlling the membrane properties and in protecting the modified membrane against UV radiation. The optimization of the coating condition not only completely protected the modified membrane from free‐radical attack initiated through UV irradiation but also improved the membrane hydrophilicity, antifouling properties, filtration performance, and mechanical strength of the membrane. UV irradiation of the membrane that was surface‐coated with a high‐concentration dopamine solution for a long coating time resulted in a higher mechanical strength than that of the membrane without the application of UV irradiation. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47312. [ABSTRACT FROM AUTHOR]