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Antiviral ultrafiltration membranes (UF) were successfully fabricated using amphiphilic polyvinylchloride-co-acrylic acid) (PVC-AA), which were incorporated with organometallic compound manganese acetylacetonate Mn(acac)3. Non-solvent induced phase separation (NIPS) method was used to prepare the UF membrane based on PVC-AA. Fabricated membranes were characterized by different analytical methods. The fabricated membranes (PVC-AA/ Mn(acac)3) provided the highest removal percentage for proteins when compared to the neat amphiphilic (PVC-AA). The hydrophilicity and antifouling properties of the membranes were improved with increasing load of manganese acetylacetonate Mn(acac)3 in the polymeric solution to 1%. The membrane with 1 wt% Mn(acac)3 (UF3) exhibited the best antifouling properties using bovine serum albumin 1 g.L−1and sodium alginate 2 g.L−1 and a real sample of wastewater namely ~ 99% of flux recovery ratio. PVC-AA- Mn(acac)3 provided antifouling and antiviral properties. The viral test using real sewage wastewater indicated that the membranes UF 2 and UF3 removes all viruses of 100%, which indicated negative detection in the treated water. [ABSTRACT FROM AUTHOR]

In lithium-ion batteries (LIBs), separators play a vital role in lithium-ion (Li+) transport, and thus affect rate performance, battery life, and safety. Here, a new kind of multifunctional copolymer poly(acrylonitrile-co-lithium acrylate-co-butyl acrylate) (PAAB-Li) is synthesized through soap-free emulsion polymerization, and is used to form homogeneous-covered separator based on PP matrix by a simple dip-annealing process. Compared to the bare PP separator, the modified separators with PAAB-Li enable higher ionic conductivity, higher lithium ion transference number (increased from 0.360 to 0.525), and lower interface impedance (reduced from 155 Ω to 34 Ω). It has been indicated that PAAB-Li functional layer significantly promotes the fast transport of Li+ and improves the compatibility of the separator/electrolyte-electrode interface. The LiCoO2/graphite cells with the PAAB-Li-assisted separator demonstrate excellent cycle stability and rate performance. In addition, the Li symmetric cells with the modified separator stably cycle over 800 h, indicating the functional layer effectively suppresses the lithium dendrite growth. This facile strategy can be easily applied to LIBs requiring high safety and even be scalable to Li metal batteries. Moreover, the possible mechanism of the PAAB-Li functional layer promoting fast and uniform Li+ transport is discussed in this paper. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Zhejiang University: Science A is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Developing a low-cost and well-recyclable adsorbent with high adsorption capacity is greatly desirable in dye wastewater treatment. Here, we demonstrate a kind of novel tough and reusable hydrogel beads with quite high capacity of dye adsorption via incorporating mussel-bioinspired poly(L-DOPA) (PDOPA) into alginate/poly(acrylamide) double network (DN) hydrogels. The synthesized PDOPA nanoaggregates were introduced into the DN hydrogels by simple one-pot mixing with the monomers prior to polymerization. The fabricated hydrogel beads exhibited high mechanical strength and good elastic recovery due to the interpenetrating Ca2+-alginate and poly(acrylamide) networks. It was shown that the beads exhibited relatively high dye adsorption capacity compared to other adsorbents reported in literature, and the introduction of PDOPA with an appropriate amount raised the adsorption capacity. It is believed that the addition of PDOPA and the matrix of double network architecture contributed synergistically to the high adsorption capacity of hydrogel beads. Moreover, the desorption of dyes could be easily realized via rinsing in acidic water and ethanol solution. The hydrogel beads remained the high adsorption capacity even after 5 times of adsorption and desorption cycles. This tough and stable hydrogel with high adsorption capacity may have potential in treatment of dye wastewater released by textile dyeing industry. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Zhejiang University: Science A is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

To functionalize poly(vinyl chloride) (PVC) for various applications, monomers containing tertiary amine group are incorporated into PVC via atom transfer radical polymerization (ATRP) initiated by the labile chlorines in their backbones. The kinetics of synthesis was carefully investigated, and it is proven that the grafting polymerization process can be effectively controlled by regulating the reaction time. The membranes are fabricated using PVC and copolymers by non-solvent induced phase separation (NIPS) process. The hydrophilicity and pore structure of copolymer membranes were enhanced as well, these membranes are endowed with positive charge. When PDMA% ( i.e., the PDMA weight percentage in copolymer) is 31.1%, the flux and Victoria blue B rejection are 26.0 L·m·h (0.5 MPa) and 91.2%, respectively. Thus, the newly synthesized polymer is proven to be a promising material for dye separation with positive charges. [ABSTRACT FROM AUTHOR]

A low operating pressure nanofiltration membrane is prepared by interfacial polymerization between m-phenylenediamine (MPDA) and trimesoyl chloride (TMC) using PVC hollow fiber membrane as supporting. A series of PVC nanofiltration membranes with different molecular weight cutoff (MWCO) can be obtained by controlling preparation conditions. Chemical and morphological characterization of the membrane surface was carried out by FTIR-ATR and SEM. MWCO was characterized by filtration experiments. The preparation conditions were investigated in detail. At the optimized conditions (40 min air-dried time, aqueous phase containing 0.5% MPDA, 0.05% SDS and 0.6% acid absorbent, oil phase containing 0.3% TMC, and 1 min reaction time), under 0.3 MPa, water flux of the gained nanofiltration membrane reaches 17.8 L/m·h, and the rejection rates of methyl orange and MgSO are more than 90% and 60%, respectively. [ABSTRACT FROM AUTHOR]

Porous PVDF blend membranes with good hydrophilicity and a symmetric structure were prepared by the phase inversion method using amphiphilic brush-like copolymers, P(MMA- r-PEGMA), as hydrophilic additive and triethylphosphate (TEP) as solvent. P(MMA- r-PEGMA) was synthesized by radical polymerization in TEP. Then the obtained amphiphilic copolymer solution was mixed with PVDF and TEP to prepare the dope solution. The effects of P(MMA- r-PEGMA) content and coagulation composition on membrane morphologies were investigated using scanning electron microscopy (SEM). The results demonstrated that, even blended with amphiphilic copolymers, a symmetric structure can be formed. Hollow fiber membranes with a mainly symmetric structure were also fabricated. The dry hollow fiber membranes showed good hydrophilicity, high flux and good rejection performance because of their hydrophilic surface and pores wall. [ABSTRACT FROM AUTHOR]

To improve the performances of HDPE-based separators, polyether chains were incorporated into HDPE membranes by blending with poly(ethylene- block-ethylene glycol) (PE- b-PEG) via thermally induced phase separation (TIPS) process. By measuring the composition, morphology, crystallinity, ion conductivity, etc, the influence of PE- b-PEG on structures and properties of the blend separator were investigated. It was found that the incorporated PEG chains yielded higher surface energy for HDPE separator and improved affinity to liquid electrolyte. Thus, the stability of liquid electrolyte trapped in separator was increased while the interfacial resistance between separator and electrode was reduced effectively. The ionic conductivity of liquid electrolyte soaked separator could reach 1.28 × 10 S·cm at 25°C, and the electrochemical stability window was up to 4.5 V (versus Li/Li). These results revealed that blending PE- b-PEG into porous HDPE membranes could efficiently improve the performances of PE separators for lithium batteries. [ABSTRACT FROM AUTHOR]

Low-pressure nanofiltratioin (NF) membranes were prepared with hydroxyl groups ended hyperbranched polyester (HPE) using polysulfone (PSf) ultrafiltration membrane as the porous support. The prepared membranes are characterized using Fourier transforms infrared spectrometry, scanning electro microscopy, atom force microscopy, X-ray photoelectron spectroscopy and water contact angle. The results indicated that the crosslinked HPE formed a uniform, ultra-thin and active layer on PSf support. Water permeability and salt rejection of the membranes were measured at the trans-membrane pressures as low as 0.3 MPa. NF membranes exhibited high enhancement in water permeability while maintaining high rejection of salts. The rejections of the nanofiltration membrane to Rhodamine B and Xylenol orange were 100 and 98.4%, respectively. The study indicated that these NF membranes could be applied to separate small organic molecules. [ABSTRACT FROM AUTHOR]

Three well-defined diblock copolymers of poly(methyl methacrylate- b-methacrylic acid) (P(MMA- b-MAA)) were synthesized using atom transfer radical polymerization method and varying poly(methacrylic acid) (PMAA) chain lengths. These copolymers were blended with PVC to fabricate porous membranes via phase inversion process. Membrane morphologies were observed by scanning electron microscopy (SEM), and chemical composition changes of the membrane surfaces were measured by X-ray photoelectron spectroscopy (XPS). Static and dynamic protein adsorption experiments were used to evaluate antifouling properties of the blend membranes. It was found that, the blend membranes containing longer PMAA arm length showed lower static protein adsorption, higher water permeation flux and better protein solution flux recovery. [ABSTRACT FROM AUTHOR]

Inspired by the self-polymerization and strong adhesion characteristics of dopamine in aqueous conditions, a novel hydrophilic nanofiltration (NF) membrane was fabricated by simply dipping polysulfone (PSf) ultrafiltration (UF) substrate in dopamine solution. The changes in surface chemical composition and morphology of membranes were determined by Fourier transform infrared spectroscopy (FTIR-ATR), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and atomic force microscopy (AFM). The experimental results indicated that the self-polymerized dopamine formed an ultrathin and defect-free barrier layer on the PSf UF membrane. The surface hydrophilicity of membranes was evaluated through water contact angle measurements. It was found that membrane hydrophilicity was significantly improved after coating a polydopamine (pDA) layer, especially after double coating. The dyes filtration experiments showed that the double-coated membranes were able to reject completely the dyes of brilliant blue, congo red and methyl orange with a pure water flux of 83.7 L/(m·h) under 0.6 MPa. The zeta potential determination revealed the positively-charged characteristics of PSf/pDA composite membrane in NF process. The salt rejection of the membranes was characterized by 0.01 mmol/L of salts filtration experiment. It was demonstrated that the salts rejections followed the sequence: NaCl < NaSO < MgSO < MgCl < CaCl, and the rejection to CaCl reached 68.7%. Moreover, the composite NF membranes showed a good stability in water-phase filtration process. [ABSTRACT FROM AUTHOR]

Supercritical carbon dioxide (scCO) was used as a reaction medium in synthesizing amphiphilic graft copolymers composed of poly(styrene- co-maleic anhydride) (SMA) backbones and methoxyl poly(ethylene glycol) (MPEG) side chains via esterification. The synthesized copolymers were characterized by Fourier transform infrared spectroscopy (FTIR), gel permeation chromatography (GPC), 1H-NMR, thermo-gravimetric analysis (TGA) and differential scanning calorimetric analysis (DSC). The gelation phenomenon was suppressed effectively by tuning reaction conditions. The influences of scCO temperature and pressure on the conversion of anhydride were investigated. It was found that the highest conversion ratio occurred at 80°C under a constant pressure of 14 MPa or 26 MPa. With the increase of scCO pressure, the conversion ratio increased first, and then leveled off. The conversion ratio of anhydride could be controlled by regulating the reaction conditions. It was also revealed that using low molecular weight MPEG brought a high conversion ratio of anhydride. [ABSTRACT FROM AUTHOR]

High density polyethylene (HDPE)/polyethylene- block-poly(ethylene glycol) (PE- b-PEG) blend porous membranes were prepared via thermally induced phase separation (TIPS) process using diphenyl ether (DPE) as diluent. The phase diagrams of HDPE/PE- b-PEG/DPE systems were determined by optical microscopy and differential scanning calorimetry (DSC). By varying the content of PE- b-PEG, the effects of PE- b-PEG copolymer on morphology and crystalline structure of membranes were studied by scanning electron microscopy (SEM) and wide angle X-ray diffraction (WAXD). The chemical compositions of whole membranes and surface layers were characterized by elementary analysis, Fourier transform infrared spectroscopy-attenuated total reflection (FTIR-ATR) and X-ray photoelectron spectroscopy (XPS). Water contact angle, static protein adsorption and water flux experiments were used to evaluate the hydrophilicity, antifouling and water permeation properties of the membranes. It was found that the addition of PE- b-PEG increased the pore size of the obtained blend membranes. In the investigated range of PE- b-PEG content, the PEG blocks could not aggregate into obviously separated domains in membrane matrix. More importantly, PE- b-PEG could not only be retained stably in the membrane matrix during membrane formation, but also enrich at the membrane surface layer. Such stability and surface enrichment of PE- b-PEG endowed the blend membranes with improved hydrophilicity, protein absorption resistance and water permeation properties, which would be substantially beneficial to HDPE membranes for water treatment application. [ABSTRACT FROM AUTHOR]

Poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) microporous membranes were prepared via thermally induced phase separation (TIPS) process. Then they were immersed in a liquid electrolyte to form polymer electrolytes. The effects of polymer content in casting solution on the morphology, crystallinity, and porosity of the membranes were studied by scanning electron microscopy (SEM), differential scanning calorimetry (DSC), X-ray diffraction (XRD), and a mercury porosimeter, respectively. Ionic conductivity, lithium-ion transference number, and electrochemical stability window of corresponding polymer electrolytes were characterized by AC impedance spectroscopy, DC polarization/AC impedance combination method, and linear sweep voltammetry, respectively. The results showed that spherulites and “net-shaped” structure coexisted for the membranes. Polymer content had no effect on crystal structure of the membranes. The maximum transference number was 0.55. The temperature dependence of ionic conductivity followed the Vogel–Tammann–Fulcher (VTF) relation. The maximum ionic conductivity was 2.93 × 10−3 Scm−1 at 20 °C. Electrochemical stability window was stable up to 4.7 V (vs. Li+/Li). [ABSTRACT FROM AUTHOR]

Hydrophilic polymers have garnered much attention due to their critical roles in various applications such as molecular separation membranes, bio-interfaces, and surface engineering. However, a long-standing problem is that their mechanical properties usually deteriorate at high relative humidity (RH). Through the simultaneous incorporation of functionalized carbon nanotubes and copper ions (Cu2+), this study introduces a facile method to fabricate high strength polyelectrolyte complex nanohybrid membranes resistant to high RH (90%). For example, the tensile strength of the nanohybrid membranes is 55 MPa at 90% RH (80% of the original value at 30% RH). These results are explained by copper ions depressing the swelling degree of the membrane, and functionalized carbon nanotubes promoting stress transfer between the polymer matrix and them. The nanohybrid membranes are efficient in separating water/alcohol mixtures containing relatively high water content (up to 30 wt%), whereas common hydrophilic polymer membranes usually suffer from excessive swelling under this condition. [ABSTRACT FROM AUTHOR]