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An urushi/Nafion hybrid membrane is prepared via a thermal in situ crosslinking reaction of natural urushiol to reduce the crossover of vanadium ions in an all vanadium redox flow battery (RFB). The ionic channel of the Nafion is blocked by the urushi, a crosslinked natural polymer formed by the polymerization of the adsorbed urushiol. Urushi, which has high chemical robustness in acid solution, is well‐formed within the volume of the ion cluster, and the presence of urushi inside the Nafion membrane is confirmed. The permeability and swelling decrease with increasing urushi in the hybrid membrane. The RFB with a hybrid membrane has higher efficiency than the RFB with Nafion. The coulombic and energy efficiencies are 95% and 91%, respectively, for the membrane containing 3.2 wt% of urushi at 11.1 mA cm−2, suggesting that the urushi in the hybrid membrane can suppress vanadium ion crossover. The chemical and mechanical strengths are maintained in Fenton reagent, which enables long‐term use of hybrid membranes to operate the RFB in strong acid solutions. These results suggest that the urushi/Nafion membrane with a chemically stable urushi inside the ion channel enables the successful use of all vanadium RFB as an energy storage system. A new urushi/Nafion hybrid membrane that has a high permselectivity of the vanadium ions for all‐vanadium redox flow battery was prepared. The ionic channel of the Nafion is blocked by the urushi, a chemically stable natural polymer network, via a thermal in‐situ crosslinking reaction. High performance was obtained using the urushi/Nafion hybrid membrane and the energy efficiency improved from 70% to 91%, due to the improved coulombic efficiency. [ABSTRACT FROM AUTHOR]

Novel composite membranes of a semi-interpenetrating network (semi-IPN) coated on the surfaces of a porous Celgard 2400 support are prepared and investigate for application in a non-aqueous redox flow battery (RFB). A natural polymer, urushi, is used for the matrix because of its high mechanical robustness, and poly(diallyldimethylammonium chloride) (PDDA) provides anionic exchange sites. The PDDA/urushi (P/U) semi-IPN film is prepared by the photo polymerization of urushiol in the presence of PDDA. The thin layer composed of the P/U semi-IPN on the porous support provides selectivity while maintaining the ion conductivity. The coulombic and energy efficiencies increase with increasing amounts of PDDA in the P/U semi-IPN layer, and the values reach 69.5% and 42.5%, respectively, for the one containing 40 wt% of PDDA. These values are substantially higher than those of the Neosepta AHA membrane and the Celgard membrane, indicating that the selective layer reduces the crossover of the redox active species through the membrane. This result implies that the formation of composite membranes using semi-IPN selective layers on the dimensionally stable porous membrane enable the successful use of a non-aqueous RFB for future energy storage systems. [ABSTRACT FROM AUTHOR]

ABSTRACT Facilitated mixed-matrix membranes (MMMs) containing Cu-metal organic frameworks (Cu-MOFs) with high CO2 selectivity on an asymmetric polysulfone support were fabricated and examined the effect of gas separation performance using different matrices. An amorphous poly(2-ethyl-2-oxazoline) (POZ) and semicrystalline poly(amide-6-b-ethylene oxide) (PEBAX®MH 1657) block copolymer were chosen as the polymeric matrix and the effect of the matrix on CO2 separation for MMMs containing Cu-MOFs was investigated. The interaction of CO2 in different matrix was investigated theoretically using the density functional theory method, and it was found that the amide segment in PEBAX would contribute more to the CO2 solubility than ether segment. The morphological changes were investigated by differential scanning calorimetry, field emission scanning electron microscope and X-ray diffractometer. The ideal selectivity of CO2/N2 was enhanced significantly with the addition of a Cu-MOF, and the values are higher in the Cu-MOF/PEBAX MMM compared with that in a POZ based asymmetric MMM. Improvement in the CO2/N2 selectivity of a Cu-MOF/PEBAX MMM was achieved via facilitated transport by the CO2-selective Cu-MOFs due to both their high adsorption selectivity of CO2 over N2 and the decreased crystallinity of PEBAX due to the presence of the Cu-MOFs, which would provide a synergic effect on the CO2 separation. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 132, 42853. [ABSTRACT FROM AUTHOR]

A poly(3,4-ethylenedioxythiophene)-b-poly(ethylene glycol) (PEDOT-b-PEG) block copolymer doped with perchlorate on FTO shows excellent optical and interfacial performance as a counter electrode (CE), such as low charge transfer resistance and low reflectivity for polymer electrolyte-based solid-state dye-sensitized solar cells (DSCs), resulting in 8.45% energy conversion efficiency, greater than the common Pt CE, via a facile room-temperature process. [ABSTRACT FROM AUTHOR]

Abstract: A series of sulfonated poly(fluorenyl ether nitrile oxynaphthalate) (SPFENO) copolymers with different degree of sulfonation (DS) are synthesized via nucleophilic polycondensation reactions with commercially available monomers. Incorporation of the naphthalanesulfonate group into the copolymers and their copolymer structures are confirmed by 1H NMR spectroscopy. Thermal stability, mechanical properties, water uptake, swelling behavior, proton conductivity and methanol permeability of the SPFENO membranes are investigated with respect to their structures. The electrochemical performance of a direct methanol fuel cell (DMFC) assembled with the SPFENO membrane was evaluated and compared to a DMFC with a Nafion 117 membrane. The DMFC assembled with the SPFENO membrane of proper DS exhibits better electrochemical performance compared to the Nafion 117-based cell. [Copyright &y& Elsevier]

Abstract: Nafion composite membranes for CO2 separation with good CO2/CH4 separation factors were developed using ionic liquids (ILs) and Nafion. Three ionic liquids containing the 1-n-hexyl-3-methylimidazolium ([hmim]) cation with different anions were characterized by the measurement of the CO2 separation performance using supported ionic liquid membranes in a polysulfone asymmetric support. Two different Nafion membrane-containing ILs for CO2 separation membranes were prepared by the adsorption of IL on a dense and electrospun Nafion/polyethyleneoxide composite membrane in order to improve the stability of the liquid membrane. The electrospun Nafion layer containing polyethyleneoxide was prepared by the electrospinning technique in order to affix [hmim][BF4] (or [hmim][PF6]) on the porous polysulfone asymmetric support. The ideal CO2/CH4 separation factor of electrospun Nafion composite membranes with [hmim][BF4] was consistent with that of [hmim][BF4]. The ideal CO2/CH4 separation factor was 26 for the Nafion composite membranes containing both [hmim][BF4] and [hmim][PF6] in the dense Nafion layer, implying a change in the microdomain of Nafion in the presence of IL and the facilitation effect of ILs for CO2 separation through the IL-swollen Nafion membrane. [Copyright &y& Elsevier]

Abstract: Organic–inorganic hybrid electrolyte membranes were prepared with a sol–gel reaction of 3-glycidoxypropyltrimethoxysilane (GPTMS) and tetraethoxysilane (TEOS) in the presence of different amounts of deoxyribonucleic acid (DNA), and compared with DNA/poly(ethylene imine) (PEI) and DNA/poly(ethylene oxide) (PEO) blend membranes with the aim of understanding the matrix effect on the electrolyte membrane properties. DNA, comprising of phosphates along a rod-like polymer of heteroatomic rings, was used as a facilitate proton transport channel in electrolyte membranes under low humidity conditions and was dispersed inside of the inorganic matrix created with the TEOS/GPTMS solution, which produced an amorphous electrolyte membrane. The proton conductivity of the DNA/TEOS/GPTMS electrolyte membranes increased with DNA loading and temperature. The proton conductivity of 30wt% of DNA in an amorphous inorganic matrix at 120°C under an N2 environment was measured at 4.9×10−4 S/cm, which is an order of magnitude higher than that of DNA in a crystalline PEO matrix and is lower than that in a more basic PEI matrix. This result implies that the main requirements for high proton transport under low humidity are the homogeneity of the membrane along with the dissociation of the proton from its ionic sites in the matrix. [Copyright &y& Elsevier]

Abstract: Liquid phase isoprene/n-pentane mixtures can be separated through the use of facilitated transport membranes containing complexes of silver ions with an ionic liquid (IL). 1-Butyl-3-methyl imidazolium tetrafluoroborate and zwitterion-type imidazolium compounds containing covalently-bound sulfonate groups form complexes with AgX (X=BF4, NO3, and ClO4). Facilitated isoprene transport has been observed with selectivities that depend on the counteranion of the silver salt. The facilitated transport phenomena of the olefin and IL/silver complexes were investigated theoretically by calculating their complexation energies (i.e., the energy of formation of the silver complexes with the olefin) with the density functional theory method. Among polymer/silver salt systems, the polymer/AgBF4 system has been found to be generally more favorable for facilitated olefin transport than the polymer/AgNO3 system because of the low lattice energy of AgBF4. However, there is a different trend for IL/AgX systems. This difference may arise because the positively charged components of the IL can interact with the anions of the silver salt, which changes the olefin complexation activity. For IL/AgX systems, the selectivity varies inversely with the complexation energy, which implies that the diffusion of the carrier may be the significant factor affecting isoprene/n-pentane separation, once the appropriate complexation has occurred between olefin molecules and the ILsilver complexes. [Copyright &y& Elsevier]

Abstract: Conductive, self-assembled DNA composite membranes supported by a nano-porous polycarbonate substrate were fabricated. The porous polycarbonate support membranes were modified with Sn2+ positive charges to induce effective DNA adsorption. Optimum pore size of 0.1μm and high pore density have been realized for track etched nano-porous polycarbonate membrane in the self-assembly process. Proton conductivity and methanol permeability (10wt.%) were evaluated to be 8.0×10-2S/cm and 5.0×10-7cm2/s for 1.6mg/cm2 of DNA loading, respectively. The self-assembled DNA composite membranes exhibit excellent proton conductivity, and enhanced mechanical properties with decreased methanol permeability. [Copyright &y& Elsevier]

Cellulose nitrate (CN) composite membranes, containing cobalt porphyrin (CoP) complexes self-assembled within nanometer-sized rhenium clusters (ReCoP), have been prepared and their oxygen and nitrogen gas permeabilities were analyzed. The solubility of ReCoP and the characteristics of the corresponding composite membranes were analyzed using a Cahn microbalance, FT-IR spectroscopy, wide-angle X-ray scattering, and differential scanning calorimetry. The nitrogen permeability through the CN composite membranes decreased upon addition of ReCoP and CoP, which implies that the presence of these oxygen carrier complexes affects the structure of the polymer matrix. The oxygen permeability through the composite membranes containing small quantities of ReCoP decreased, but it increased upon increasing the concentration. The oxygen gas transport was affected by the matrix at low ReCoP concentrations, but higher concentrations of ReCoP increased the oxygen permeability as a result of its reversible and specific interactions with oxygen, effectively realizing ReCoP carrier-mediated oxygen transport. [ABSTRACT FROM AUTHOR]

Remarkably high-performance membranes are developed by physically dispersing silver ionic aggregates in inert polymer such as poly(dimethyl siloxane) (PDMS). The mixed gas selectivity for propylene/propane reaches nearly 200, to our knowledge the highest value ever reported for the solid state, whereas other membranes reported up to now show ∼60 of propylene/propane selectivity. Physical dispersion of silver salt in the inert polymers without specific interaction is observed by FT-IR, FT-Raman and wide angle X-ray scattering (WAXS). It is also found that the crystalline silver ionic aggregates are completely dissolved under the propylene environment, representing that propylene is a good ligand for coordination to silver ions. The inert membranes are functional at any loading level and hence a threshold carrier concentration does not exist. [Copyright &y& Elsevier]

Recently, researches about polymer electrolytes have been spotlighted owing to their potential applications in polymer batteries, fuel cells and solar cells. To our knowledge, no report has been published on polymer electrolytes by π-complexation between transition metal ion and olefinic ligand of a polymer matrix although several have been reported by the coordination between metal ion and nonbonding electrons of oxygen, nitrogen, etc. In this communication, we report that polymer electrolytes consisting of silver salt and polymer containing C&z.dbnd6;C bond are developed and especially applied to the facilitated olefin transport membranes for the separation of olefin/paraffin mixtures. [Copyright &y& Elsevier]

Polymer electrolytes containing silver salts have gained great interest due to their effective performance in the separation of olefin/paraffin mixtures. However, they suffer from the poor long-term stability. The membrane performance of polyvinylpyrrolidone (PVP)/AgBF4 membranes was decreased with time primarily due to the reduction of silver ions to silver metal. In this study, non-ionic n-octyl β-d-glucopyranoside (8G1) surfactant has been employed to prolong the stability of the separation performance of PVP/AgBF4 membranes. It was found that the growth rate of the silver particles became slower and the propylene permeability was maintained for much longer time when 8G1 was added into the membranes. The reduction behavior of silver ions to silver metal particles and their growth were investigated by Transmission electron microscopy (TEM), scanning electron microscope (SEM), and UV spectroscopy. [Copyright &y& Elsevier]

Structural characteristics and membrane performance of polystyrene-block-poly(ethylene-ran-butylene)-block-polystyrene (sSEBS) copolymer proton exchange membranes in water-swollen and different ratio of water/methanol-swollen are studied by small angle X-ray scattering (SAXS), ATR FT-IR, AFM. SAXS profile of sSEBS membrane showed that microstructure was a hexagonally cylindrical structure and it was maintained in the existence of methanol in water until 30 wt.%. As the main interest was on the development of proton exchange membranes for fuel cells operating at lower temperature with liquid methanol feed, a selective thin layer was introduced on the top of sSEBS membrane by simple plasma treatment in the presence of maleic anhydride in order to prevent methanol crossover. Both methanol permeability and proton conductivity gradually decreased with increasing loading amounts of maleic anhydride. Hydrophobic anhydride properties on the top of sSEBS membrane act as a barrier for methanol but also for proton, resulting in decreasing methanol permeability and proton conductivity. The hydrolysis of anhydride groups to carboxylic acid provides a facilitated transport site for the proton. After hydrolysis, the proton conductivity was recovered and the recovery rate of proton conductivity by hydrolysis was higher than that of methanol permeability. [Copyright &y& Elsevier]