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Using cation compounds as raw materials, three quaternized microblock poly(p-phenylene-co-aryl ether ketone)s (s-, m-, and l-QPP-co-PAEK) were synthesized using a nickel (0)-catalyzed coupling reaction. Hydrophilic and hydrophobic moieties were affixed using cationic quaternary ammonium (QA) groups attached to poly(p-phenylene) by a three-carbon interstitial spacer and nonionic dichloride monomers of various lengths, respectively. The morphology, water uptake, swelling ratio, mechanical properties, thermal stability, hydroxide conductivity and alkaline stability of these new membranes were investigated. Experimental results indicated that the membrane with the longest hydrophobic microblock exhibited high hydroxide conductivity (37.6 mS cm−1 at 80 °C) resulting from the aggregation of ionic clusters observed using TEM. The copolymers with longer hydrophobic nonionic segments exhibited improved alkaline stability, suggesting that the hydrophobic chain shields the QA groups and that the polymer chains pack in a manner that restricts rotation. Controlling the distribution of QA groups in poly(p-phenylene) moieties and tuning the block length of nonionic segments are demonstrated to be effective methods for improving the hydroxide conductivity and alkaline stability of anion exchange membranes.

Functionalized polysulfone (PSf) membranes with combined antibacterial and antifouling properties were fabricated by incorporating a poly(ethyleneoxide)-grafted (PEO-grafted) amphiliic polymer. Both antifouling and antibacterial groups were easily introduced onto the membrane surfaces through non-solvent induced phase separon process and a simple chlorination process. It was observed that the functionalized membranes were effectivatie in resisting both protein absorption and bacterial adhesion. Furthermore, the functionalized membrane (M3-Cl) showed mostly suppressed irreversible flux decline and a 97% flux recovery ratio after simple washing during the separation process, indicating excellent antifouling properties. Meanwhile, the functionalized PSf membrane exhibited efficient biocidal activity against E. coli and S. aureus. These modified functionalized PSf membranes also displayed outstanding properties in inhibiting the formation of biofilm. Moreover, the antibacterial feature was renewable by a simple process.

Directional liquid transport driven by the interface or surface property of Janus porous membrane owes great significance to many applications such as separation technology, fog collection, and energy devices. The Janus porous membranes have successfully demonstrated an efficient oil self-transport in water and also enable directional water transport in air or oil-water interface. However, the directional water transport in oil environment is a challenge because of the relatively low surface tension of oil. In this work, a novel integrated Janus porous membrane is developed for the first time to construct self-propelled energy free directional water transport in oil system that successfully demonstrated to be a facile “water diode” for under-oil water one-way regulation. Additionally, this Janus porous membrane exhibits an interesting tunable fluid-gating behavior for either water or oil, using optimized conditions. The current findings may promote the innovation towards directional liquid transport science and will open up new avenues for diverse on-demand liquids manipulation scenarios such as water-in-heavy oil emulsion separation.

The development of polymer exchange membranes (PEMs) with high proton conductivity under high temperature and low relative humidity (RH) conditions is important to the improvement of the comprehensive performance of the fuel cell. In this paper, we present a novel approach for the design of semi-crystalline fluorinated PEMs (FSPP-1) via Ni(0)-catalyzed coupling polymerization. The structural characteristics of FSPP-1 are composed of retaining a portion of the fluorinated matrix (coil units) and introducing aromatic π-π interactions in the hydrophilic block (rod units), as well as precisely controlling the same block length along the main chain axis, which is a similar, molecular-level approach as the prototypical Nafion™ 117. The morphology, water state, and proton conductivity of FSPP-1 were investigated in detail, and the results show higher proton conductivity at 40% RH at 80 °C. The study also revealed that a dense, narrow distribution of hydrophilic nanochannels were formed with good connectivity of the hydrophilic nanochannels in FSPP-1. More importantly, π-π interactions in the hydrophilic block and helical perfluoroalkyl chains in the hydrophobic block coexisted in FSPP-1 ionomers, forming more small and dense crystallite domains, which was found to be beneficial to improving the stability of the nanochannels at elevated temperature and low RH. This strategy to simultaneously increase the density of ion transport channels and high temperature stability provides a baseline for the molecular-level design of high temperature PEMs.

The poly(aryl ether ketone) with spatial cardo structure is prepared from 4,4′-bis(phenoxy)benzophenone and 1-(4-bromobutyl)indoline-2,3-dione through a facile polyhydroxyalkylation reaction catalyzed by superacid. The number average molecular weight of the resultant polymer is achieved as high as 105.6 kg mmol−1. Three anion exchange membranes were prepared by reacting the polymer with trimethylamine, N-methyl-piperidine, and N,N,N′,N′,N″-pentaethylguanidine, respectively. Among the prepared membranes, N-methyl-piperidine based anion exchange membrane exhibited the highest OH− conductivity of 99.8 mS cm−1 at corresponding IEC of 1.54 meq g−1. In addition, the prepared membranes also exhibit excellent mechanical properties, in which the tensile strength and elongation at break can reach up to 50 MPa and 35%, respectively. Moreover, the anion exchange membranes exhibited good alkaline stability. When they were treated with 1 M KOH at 60 °C for 600 h, their conductivity decreased by less than 5%.

Developing of polymeric material with high stability is the key to the progress of organic solvent nanofiltration (OSN) membranes. As a semi-crystalline polymer with rigid aromatic backbone structure, poly(ether ether ketone) (PEEK) has good resistance to most of the organic solvents. However, the preparation of PEEK asymmetric membranes is hindered by its inherent insolubility in common solvents. In this work, a chemical-induced crystallization (CIC) strategy involving fabrication of asymmetric membranes from its precursor polymer-poly(ether ether ketimine) (PEEKI) and then converting to PEEK by acid treatment was proposed. The results indicated that the obtained membranes could be used stably in various organic solvents, and the optimal membrane exhibited a DMF permeance of 4.19 L m-2 h-1 bar-1 and a molecular weight cut-off of 350 g mol−1 in DMF, which was an order of magnitude higher than the PEEK OSN membranes prepared from the sulfonic acid solvents. Meanwhile, the developed PEEK membranes also possessed good pressure resistance for long-term nanofiltration. Our study has proven the feasibility of fabrication PEEK asymmetric membranes through the CIC strategy for OSN application.

A self-assembly strategy has been developed for the synthesis of anion-exchange membranes (AEMs) with high alkaline stability. Cardo poly(aryl ether sulfone ketone)s with pendent tertiary amine groups were grafted with alkyl siloxane to form a polymer with cation quaternary ammonium groups. This polymer produced a zwitterionic polymer via partially hydrolysis of the alkyl siloxane in weak basic medium. The flexible and transparent zwitterionic polymer membranes possessing a Si-O-Si cross-linked network were prepared via the sol-gel polycondensation reaction and a self-assembly process. The homogeneous and continuous Si-O-Si cross-linked network inhibited membrane swelling and improved the mechanical properties and thermochemical stability. The membrane showed alkaline stability in 1 M NaOH aqueous solution at 60 °C for 600 h and solvent resistance in polar aprotic solvents (DMAc, NMP, and DMSO) at 60 °C for 30 days.

A series of tetra-sulfonated poly(p-phenylene-co-aryl ether ketone) membranes (l-tSPP-co-PAEK x) with microblock moieties have been synthesized by nickel (0) catalytic coupling copolymerization and show good dimensional stability. Compared with the mono-sulfonated poly(p-phenylene-co-aryl ether ketone) membranes (SPP-co-PAEKs), the relationships between water content, the state of water molecules, proton conductivity, methanol permeability, and morphology for the membranes are detailedly investigated. Analyses by small-angle X-ray scattering (SAXS) and transmission electron microscopy (TEM) show that the l-tSPP-co-PAEK x greatly facilitated the connected proton transport channel. The proton conductivity of l-tSPP-co-PAEK x membrane is up to 60.0 mS cm−1 at room temperature, which is 32% higher than that of the proton conduction in SPP-co-PAEKs, despite the IEC values are lower than that of the latter. The membranes exhibit high power densities in the range of 27.5–31.9 mW cm−2 for passive direct methanol fuel cells (DMFCs) at room temperature. The power density of l-SPP-co-PAEKs 1.20 is higher than that of commercial Nafion 115 (29.3 mW cm−2) and Nafion 117 (24.3 mW cm−2) under same test conditions. The desirable properties of l-tSPP-co-PAEK x membranes can be attributed to the synchronous introduction of locally and densely sulfonated hydrophilic units and hydrophobic microblock moieties in the membrane structure, resulting in the formation of the connected proton transport channel.

The bacteria-repellent and bactericidal functionalities in a single system are generally need to be carefully optimized in order to obtain the highest antibacterial performance. In this study, the controlled SI-PIMP strategy was developed for creating hierarchical polymer brushes possessing the bacteria-repellent and bactericidal functionalities. To obtain a bactericidal surface with minimal interference to its nonfouling property, optimization studies were conducted by facilely tailoring the surface density of the quaternary ammonium compound moieties through control over the monomer concentration. An optimal hierarchical polymer coating showed potent protein and bacteria repellence as well as certain bactericidal property. The longlasting antibacterial performance was also achieved due to the good balance between the dual functionalities. The tenability of the hierarchical polymer coating is applicable to surface chemistries for biosensors, molecular imaging, and biomedical applications.

Thin film composite nanofiltration membranes were fabricated by coating a water-soluble disulfonated poly(arylene ether sulfone) which contained pendant amine groups (SPES-NH2) onto a polysulfone support in conjunction with covalent crosslinking. Two different crosslinkers, glutaric dialdehyde (GA) and poly(ethylene glycol) diglycidyl ether (PEGDGE), were utilized with various concentrations and curing temperatures to optimize the performance of the resulting membranes. Both GA and PEGDGE crosslinked membranes exhibited optimal performance with a 1 wt.% polymer concentration and 90 °C curing temperature. In particular, the optimized PEGDGE crosslinked membranes exhibited a higher permeation flux of 25.5 ± 3.0 L m−2 h− 1 while that of the GA crosslinked membranes was 8.9 ± 3.2 L m−2 h− 1; each membrane exhibited similar levels of Na2SO4 rejection at 96.1 ± 1.1% and 96.6 ± 2.1%, respectively, at 4 bars. The higher flux for the PEGDGE crosslinked membranes was attributed to higher hydrophilicity. Furthermore, the rejection of methyl orange and methyl violet was above 99.9% for both the GA and PEGDGE crosslinked membranes. A fouling study of the PEGDGE crosslinked membrane was carried out using humic acid as a model foulant, and the membranes exhibited excellent antifouling ability, attributed to their high hydrophilicities and strongly anionic characteristics.

Surface modification is a promising way to improve membrane performance. In this study, a commercial aromatic polyamide thin-film composite reverse osmosis membrane was modified through sequential surface treatment with glutaraldehyde aqueous solution followed by polyvinyl alcohol (PVA) aqueous solution. ATR-FTIR spectroscopy, SEM, AFM, measurements of streaming potential and contact angle and cross-flow permeation tests were employed to investigate the influence of modification on membrane performance. It was illustrated that PVA molecules were covalently attached on the surface of the pristine membrane and both membrane surface physico-chemical and permeation properties could be tuned through changing the PVA content. The covalent attachment of PVA resulted in an improved surface hydrophilicity, a declined surface negative charge and a slightly increased surface roughness, and could enhance membrane salt rejection and water flux simultaneously. The modification was proved to be effective in improving membrane antifouling property to the foulants of bovine serum albumin, sodium dodecy sulfate and dodecyltrimethyl ammonium bromide through increasing anti-adsorption capability and in enhancing membrane chlorine stability through reducing chlorination sites and preventing the underlying polyamide backbones from chlorine attack. Furthermore, the modification could effectively enhance the membrane rejection performance and antifouling property in tertiary treatment of industrial effluent.

Thin film composite nanofiltration membranes were fabricated through dip-coating and in situ cross-linking of quaternized poly(ether ether ketone) containing a certain amount of tertiary amine groups (QAPEEKs) on polyacrylonitrile (PAN) support. The effects of the variables in membrane formation such as the coating polymer concentration, the curing temperature, and the cross-linking agent types on resultant membrane were studied and the membrane properties such as the barrier layer chemical structure, the surface element composition and morphology were investigated. The obtained performance of uncross-linked and cross-linked QAPEEK-70 thin film composites in nanofiltration test was compared. The results indicated that the cross-linking improved the composite membranes' performance. For instance, the membrane cross-linked by bisphenol A diglycidyl ether (BPADGE) named M-C-BPADGE exhibited a MgCl2 rejection of 97.8%, a water flux of 11.8Lm(-2)h(-1), a MWCO of 800Da and corresponding pore size of 0.69nm, while for its uncross-linked membrane named M-U, a MgCl2 rejection of 91.2%, a water flux of 13.5Lm(-2)h(-1), a MWCO with 960Da and a pore size of 0.77nm were found. Furthermore, the M-C-BPADGE membrane exhibited selectivities of 16.0 for separation of mixed Mg(2+) and Na(+) cations, much larger than selectivity of 5.2 obtained for M-U, suggesting that the cross-linked membranes are promising in cation separation.

It has been reported that introducing graphene oxide (GO) or functionalized GO into proton exchange membranes (PEMs) can inhibit methanol diffusion by increasing the complexity of the methanol diffusion pathway in the hydrophilic region. In fact, methanol permeation also occurs in the hydrophobic area, which is very important, but rarely studied. In this study, we propose a facile and effective in-situ cross-linking method to prepare GO/sulfonated poly (p-phenylene-co-aryl ether ketone) crosslinked PEMs. By using the sulfonic acid group in parent polymer as a solid acid catalyst, the –COOH groups in GO undergo the Friedel-Craft acylation with the nucleophilic phenyl rings in the hydrophobic segments under vacuum heating, and the construction of covalent cross-linking network between GO and hydrophobic region is achieved successfully. The obtained crosslinked membranes show obviously reduced methanol crossover and greatly enhanced selectivity. The highest power density of the passive DMFC is obtained by using the 2 wt% GO crosslinked membrane and its value (28.1 mW cm-2) is higher than the original parent polymer (24.4 mW cm-2). These results demonstrate that the hydrophobic phase is closely relevant to the transport of methanol molecules in the membrane, which provides a new idea for the construction of methanol-blocking PEMs.

The anion conductive polymers based on the aryl ether-free polyaromatics (poly[(fluorene alkylene)-co-(biphenyl alkylene)] (PFBA), poly(fluorene alkylene) (PFA)) and aryl ether-containing polyaromatics (poly(2,6-dimethyl-1,4-phenylene oxide) (PPO)) having various cation groups (quaternary ammonium (QA) or bulky imidazolium (MIm or PIm)) were designed and prepared to investigate the effect of polymer backbones and cation functional groups on the properties of anion exchange membranes (AEMs) in fuel cells. The PFBA AEM having bulky imidazolium group showed good mechanical properties while the PPO AEM with the same cation break into the pieces. The alkalinity of the bulky imidazoliums have determined to be weaker than that of the typical quaternary ammonium by the simulation. Thus, the high hydroxide conductivities of the AEMs based on the quaternary ammonium group have been observed. Although the alkaline stability testing in 2 mol L−1 NaOH at 80 °C indicated the AEMs based on the PFBA backbone are much more alkaline stable than that of the AEMs from PPO backbone, the PFA-QA having typical quaternary ammonium showed significant degradation signals in 2 mol L−1 NaOD CD3OD/D2O solution at 80 °C for 15 days while PFA-MIm with bulky imidazolium groups showed no degradation signal at the same testing condition. The single H2/O2 fuel cell testing at 60 °C suggested the polymer backbone and cations displayed significant effect on the fuel cell performance. The highest peak power density of 610 mW cm−2 was achieved for PFBA-QA-0.4 which is approximate twice as high as that of the PPO-QA-0.4 (351 mW cm−2) and also the PFBA-MIm-0.4 having bulky imidazolium (32 mW cm−2). The device durability test indicates that the voltage of PFBA-QA-0.4 membrane could be maintained above 0.7 V at 200 mA cm−2 for 74 h. These results suggested that the aryl ether-free polymer backbone would be a good choice for the high performance AEM designation, and the AEMs having alkaline stable bulky imidazoliums needed to be further investigated in detail to achieve excellent fuel cell performance.

In the overall alkaline stability for guanidinium cations, the substituted mode has been proven to play a very important role. Free and bulky alkyl substituents such as ethyl groups in guanidinium cations can provide large steric hindrance to resist the OH− attack and achieve much higher stability than conventional methyl-substituted ones. To obtain high-dimensional and good alkaline stabilities of anion exchange membranes (AEMs), linking the stable guanidiniums through suitable crosslinked structures (with different spacer structures or lengths) is a feasible strategy. In this study, bi-guanidinium-based crosslinked AEMs were prepared by Menshutkin reactions using brominated poly(2,6-dimethyl-phenylene oxide) and bi-guanidine crosslinkers followed by a complete quaternization of the remaining guanidine. The prepared membranes possess a low swelling ratio (

The porous 2D covalent organic nanosheets (CONs) membrane has become a new generation of membrane material due to its ultrahigh permeation flux. The main challenge in fabricating CONs membrane is how to exfoliate covalent organic frameworks (COFs) into large-scale, few-layer nanosheets. Herein, we presented a simple and economical azobenzene template approach for exfoliating 2D COFs into large nanosheets and achieved fabrication of ultrathin CONs membrane successfully. Three COFs with different skeleton structures were chosen to explore the influencing factors for effective exfoliating. We found that the compatibility between azobenzene molecules and COFs skeleton structure was the key point for exfoliation. When the COF skeleton matching with the azobenzene molecular structure, COFs can be easily exfoliated into larger-scale CONs than nanosheets prepared by conventional exfoliation methods. The as-exfoliated nanosheets membrane showed a higher water flux (596 L m2 h-1 bar-1) than a graphene oxide (GO) membrane (4.3 L m2 h-1 bar-1) and high rejection of dye molecules, due to the nano-channels perpendicular to the surface of the membrane.

A facile and tunable strategy is proposed to fabricate the Janus porous membrane (JPM) comprising hydrophobic and controlled-hydrophilic wetting surfaces. The control over the wettability of hydrophilic surface is well achieved by tuning the temperature, reaction time, and surface modification. The JPM has directional cross-plane water transport ability, which is demonstrated in water harvest. The prepared JPM exhibits an interesting cross-plane unidirectional selectivity for oil transport at oil-water interface. The synergistic effect developed due to the directional oil transport and charge-screening, which offered an efficient separation of both the heavy oil and light oil from oil-in-water emulsions utilizing large pore size JPM. This easy-to-prepare and tunable strategy endows the JPM with many practical applications that is important for the evolution of JPM from a scientific concept to practical materials in real world.

To study the effect of cation groups on the alkaline stability and other properties of anion exchange membranes (AEMs), common quaternary ammonium (QA), N-alicyclic quaternary ammonium and imidazolium cations with bulky substituents were grafted onto an aryl ether-free polyaromatic backbone synthesized via acid-catalyzed polyhydroxyalkylation. The size of cation groups is calculated by Gaussian. The size of bulky imidazolium (MIm) is much larger than QA and N-alicyclic quaternary ammonium (Py and Pi). Because of the large size of the cation groups, the chain entanglement density of AEM with bulky imidazolium (PFBA-MIm-0.4) is lower than other three membranes, resulting PFBA-MIm-0.4 displays the highest water uptake of 225.1% at 80 °C, whereas the IEC of PFBA-MIm-0.4 is the lowest (1.49 mmol g−1). Meanwhile, the toughness of the membranes decreases when the size of the cation group increases. AEM with common quaternary ammonium (PFBA-QA-0.4) exhibits the highest hydroxide conductivity of 142 mS cm−1 at 80 °C because it exhibits the highest ion exchange capacity (IEC). More interestingly, PFBA-QA-0.4 shows long term alkaline stability that is as good as that of the AEMs with alicyclic quaternary ammonium or bulky imidazolium, even in 5 mol L−1 aqueous NaOH at 80 °C; however, the small size of the substituents of common quaternary ammonium does not have steric hindrance that is as large as that of the substituents of alicyclic quaternary ammonium and bulky imidazolium. Therefore, we selected PFBA-QA-0.4 to prepare a membrane electrode assembly for the further study of alkaline H2/O2 fuel cell performance. The single H2/O2 fuel cell exhibits a peak power density as high as 559 mW cm−2 at 80 °C under 100% RH with 0.1 MPa backpressure. These results of the comparison of AEMs with different size cation groups give some insights for future directions in the development of advanced AEMs.

With global warming, hazards relating to glacial melt, such as glacial lake outburst floods, are becoming progressively more serious. However, glacial melt processes and their hydrological consequences are very poorly understood. This study collected glacier discharge data from the terminus of the Parlung No. 4 Glacier throughout the melt season (May-October) during 2008, 2010, 2011 and 2012 to study its specific hydrological characteristics. Time series and multivariate regression analyses were employed to investigate the relationships between discharge and meteorological factors involved, as well as their correlation to discharge estimations. The 0- to 3-day time series analysis showed that discharge rates were highly autocorrelated and that discharge was significantly positively correlated to air temperature, vapour pressure and daily incoming shortwave radiation as well as weakly positively correlated to precipitation. A multiple-regression exponential model using the independent variables of the daily mean temperature and the vapour pressure exclusively was applied to simulate daily discharge in the basin with a high degree of accuracy. On average, July yielded the maximum monthly mean discharge, followed by August. Discharge in July and August accounted for 53% of the total discharge during the main melt season. The daily cycle of discharge changed as the melt season progressed, reflecting hydrological processes and characteristics of snow melt and glacier ice/snow melt, as well as their transitional periods. Subsequently, regular variations in the characteristics of the diurnal cycle of discharge, storage and delay were observed as the melt season progressed. In addition, the reasons behind the inter-annual variation in the characteristics of discharge and glacier discharge from the Tibetan Plateau and its surrounding areas are compared and discussed. Copyright (c) 2015 John Wiley & Sons, Ltd.

A series of comb-like amphiphilic copolymers (PES-g-PEO) were synthesized through grafting poly(ethylene oxide) (PEO) to cardo poly(aryl ether sulfone) (PES-NH) backbone. By controlling the ratios of PEO and cardo poly(aryl ether sulfone), amphiphilic copolymers with a range of PEO side chain were obtained and were employed to ultrafiltration (UF) membranes. The PES-g-PEO-XX materials showed high thermal stability (Td > 238 °C) and good mechanical properties especially elongation at break reached to 150% compared to 23% of PES-NH. The contact angle of PES-g-PEO-80 asymmetric membrane was decreased to a slow as 59° which was 30° lower than the value of PES-NH membrane (90°), indicating that PES-g-PEO-80 membrane exhibited remarkable hydrophilic property. No protein adsorption was found on the surface of PES-g-PEO-60 and PES-g-PEO-80 membranes, showing excellent antifouling properties compared to PES-NH. The results of this work suggest that PES-g-PEO copolymers are promising materials for the fabrication of fouling resistant membranes.

Tibetan glaciers experience spatially heterogeneous changes, which call for further investigation of the mechanisms responsible from an energy and mass perspective. In this study, 2 year parallel observations (August 2010–July 2012) at 5665 m a.s.l. on Zhadang glacier (a subcontinental glacier) and 5202 m a.s.l. on Parlung No. 4 glacier (a maritime glacier) were used to reveal the drivers of surface energy and mass balance at these sites. Glacio-meteorological data show that air temperature and specific humidity were 1.7°C and 0.5 g kg−1lower on Zhadang glacier than on Parlung No. 4 glacier. The mass accumulation occurred primarily before the Indian summer monsoon onset on Parlung No. 4 glacier and after its onset on Zhadang glacier. Point net mass loss was 2.5 times larger on Parlung No. 4 glacier than on Zhadang glacier, mainly due to the difference in melt energy. Overall, the physical mechanisms controlling the mass and energy difference can be attributed to both the feedback role of surface albedo through different snow accumulation characteristics and longwave radiation emission of the atmosphere due to different meteorological backgrounds. Finally, a review of the few studies dealing with energy balance on the Tibetan glaciers describes the possible spatial characteristics requiring further investigation in the future on larger spatial and temporal scales.

Polyelectrolyte complex membranes were prepared from poly(acrylic acid-co-acrylonitrile)s and imidazolium-based polycations via a combination of blend film casting and ammonia solution immersion procedures. The membranes were free-standing and tough, showing excellent mechanical properties (with tensile strength of 6.71–23.7 MPa and elongation at break of 15–59%). Hierarchically structured nanopores were formed in the membranes during the ammonia soaking step, due to NH3-triggered –COOH deprotonation and in situ ionic crosslinking with polycations. Zeta potential measurements indicated that the membranes were negatively charged under neutral conditions. The membranes exhibited moderate rejection to salts in the order of Na2SO4 > NaCl > MgCl2, but high rejection to methyl orange (>99.9%).

Alkaline anion-exchange membranes (AAEMs) for solid alkaline fuel cells (SAFC) application were successfully prepared by radiation induced grafting of Vinyl benzyl chloride onto ultra-high molecular weight polyethylene powder (UHMWPE), followed by film fabrication by melt pressing and quaternization with a Guanidine derivative, 1,1,3,3-tetramethyl-2-n-butylguanidine (TMBG). The chemical structures of the resulting AAEMs were examined by Fourier transform infrared, which showed that the grafted membranes were successfully functionalized by modified guanidine. The performance of the AEMs, including ion exchange capacity, water uptake, in-plane swelling, methanol uptake, methanol permeability, and hydroxide ion conductivity were investigated. Thermal analysis showed that the Guanidine-based AAEMs comprises better thermal stability. The AAEMs membrane exhibited a maximum ionic conductivity of 27.7 mS cm −1 at 90 °C. Methanol permeability is found to be in the order of 10 −9 cm 2 s −1 , which is significantly lower than that of Nafion ® . The membranes have useful properties as an anion exchange membranes suitable for alkaline fuel cells.

A series of poly(arylene ether sulfone) containing bulky imidazole groups (PSf-Im-x) have been successfully synthesized based on a novel monomer 2,2′-bis-(2-ethyl-4-methyl-imidazole-1-ylmethyl)-biphenyl-4,4′-diol (EMIPO). After quaternized by n-bromobutane, these polymers are evaluated for alkaline anion exchange membranes (AEMs). The functional group, 2-ethyl-3-butyl-4-methyl-imidazolium, is employed in these new polymers for reason that attaching bulky groups around the imidazolium ring reduces the access of OH− to imidazolium, which enhances the alkaline stability of the membranes. The membrane with an IEC value of 2.07 possesses ionic (OH−) conductivity of 0.014 S cm−1 at 30 °C and 80% of the ionic conductivity is maintained after treatment in 1 M KOH at 60 °C for 144 h.

Studies have been devoted to the transport and accumulation of persistent organic pollutants (POPs) in mountain environments. The Himalayas have the widest altitude gradient of any mountain range, but few studies examining the environmental behavior of POPs have been performed in the Himalayas. In this study, air, soil, and leaf samples were collected along a transect on the southern slope of the Himalayas, Nepal (altitude: 135–5100 m). Local emission occurred in the lowlands, and POPs were transported by uplift along the slope. During the atmospheric transport, the HCB proportion increased from the lowlands (20%) to high elevation (>50%), whereas the proportions of DDTs decreased. The largest residue of soil POPs appeared at an altitude of approximately 2500 m, and may be related to absorption by vegetation and precipitation. The net deposition tendencies at the air–soil surface indicated that the Himalayas may be a ‘sink’ for DDTs and PCBs.

A novel bisphenol monomer bearing a cyclic tertiary amine was prepared in good yields by the acid-catalyzed reaction of N-methyl-4-piperidone and phenol. Tertiary amine poly(aryl ether sulfone) (TAPES) with high molecular weights of up to 95.3 kg mmol−1 and good thermal stability was synthesized by nucleophilic substitution of the bisphenol monomer with 4,4′-dichlorodiphenyl sulfone. The spatial separation between the cyclic tertiary amine groups and the hydroxyl ortho-position improves the stability of the intermediate and was the key to the polymerization. The anion exchange membranes (AEMs) QPES or DQPES are obtained by quaternization of TAPES with methyl iodide or (3-bromopropyl)trimethylammonium bromide, respectively. DQPES (ion exchange capacity = 3.12 mmol g−1) shows a higher ion conductivity of 59.8 mS cm−1 and reasonable dimensional stability in water at 80 °C. DQPES membrane revealed that the high conductivity might be due to its phase-separated structure in small-angle X-ray scattering test. The alkaline stability of QPES and the methoxy-capped QPES was compared, end-capping was found to improve the stability of piperidinium cations. This method offers a versatile platform for cost-effective synthesis of piperidinium-based AEMs with poly (aryl ether) backbones, and may provide a strategy to improve alkaline stability.

We report a new hydroxyl functionalized microporous organic polymer (MOPOH) based on the polymerization of catechol with terephthalaldehyde using phenolic resin-inspired chemistry. This catechol-decorated material, with surface area of 874 m2 g−1 and micro, mesopores, facilitates the immobilization and dispersion of Pd nanoparticles (NPs) on the polymer matrix. The surface area of the created composite (Pd@MOPOH) decreases to 419 m2 g−1 and the pore size distribution is narrowly distributed at 1.54 nm due to the filling of mesopores. The CO2 capture capacities for MOPOH and Pd@MOPOH at 273 K and 1 bar are 13.4 and 9.2 wt%, respectively. The resultant Pd NPs are crystalline and uniform with a mean diameter of 4.8 nm. The well-dispersed Pd@MOPOH exhibits excellent catalytic activity toward the model reduction of 4-nitrophenol into 4-aminophenol. Significantly, nearly no Pd leaching is detected during the catalytic cycles, showing active and durable nature of the heterogeneous nanocatalyst.

This article describes the synthesis and characterization of microporous organic copolymers (PP-N-x, where "x" is the molar percent of triphenylamine) prepared from triphenylamine and dichloro-p-xylene using a combination of oxidative polymerization and Friedel Crafts alkylation process promoted by anhydrous FeCl3. The samples possessed BET specific surface areas from 318 to 1530 m(2) g(-1) with the increasing content of dichloro-p-xylene. The highest CO2 uptake of 4.60 mmol g(-1) was observed for PP-N-25, which was one of the highest values among MOPs reported to date under these conditions. The polymers possessed stable and reversible CO2 adsorption-desorption performance in at least 5 consecutive runs without noticeable deterioration of CO2 uptake capacities. (C) 2013 Elsevier Ltd. All rights reserved.

[1] Based on glaciometeorological measurements and mass balance stake records during the 5 year period of 2005–2010 on the southeast Tibetan Plateau, an energy-mass balance model was applied to study the surface mass balance of the Parlung No. 94 Glacier, as well as its response to regional climate conditions. The primary physical parameters involved in the model were locally calibrated by using relevant glaciometeorological data sets. The good agreement between the snowpack height/mass balance simulations and the in situ measurements available from a total of 12 monitoring stakes over this glacier confirmed the satisfactory performance of the energy-mass balance model. Results suggested that the recent state of the Parlung No. 94 Glacier was far removed from the “ideal” climatic regime leading to zero mass balance, with its annual mass balance of approximately −0.9 m water equivalent during 2005–2010. Climatic sensitivity experiments were also carried out to interpret the observed mass balance changes, and the experiments demonstrated that the maritime glaciers concerned herein were theoretically more vulnerable to ongoing climate warming on the Tibetan Plateau than potential changes in the amount of precipitation. A plausible causal explanation for the recent glacier shrinkage in this region was concerned with the increasing air temperature. Moreover, both the mass balance simulations and the field measurements indicated that the mass accumulation over this maritime glacier occurred primarily in the boreal spring. Such “spring-accumulation type” glaciers are presumed to be distributed mainly within a narrow wedge-shaped region along the Brahmaputra River. Climatic sensitivities of the glacier mass balance are also found to be closely linked to the regional precipitation seasonality that is simultaneously modulated by various atmospheric circulation patterns, such as the southern westerlies, the Bay of Bengal vortex in the spring season, and the Indian monsoon in the summer season.

Summary This project launched a comparative study to investigate the areas of the Zhadang glacier (on the leeward slope/north slope of the West Nyainqentanglha Range, Tibetan Plateau) and the Gurenhekou glacier (on the windward slope/south slope) for nearly 40 years (1970–2007) and measure the mass balance of the two glaciers for three (2005–2008) and four (2004–2008) mass balance years, respectively. Results show that, in 1970–2007, overall annual precipitation decreased slightly caused by the weakening Indian monsoon and strengthened westerlies and annual mean air temperatures increased gradually in the areas to the north and south of the West Nyainqentanglha Range, respectively, resulting in the areas of the two glaciers reduced over the last nearly four decades. The rate of air temperature increase in the north is higher than that in the south. Moreover, mean annual precipitation in the south exceeds that in the north, due to the weakening of the Indian Monsoon activities across the West Nyainqentanglha Range. As a result, the area decrease of Zhadang glacier in the north slope of the West Nyainqentanglha Range is more intensive than that of Gurenhekou glacier in the south slope. Results also show that these two small glaciers experienced gradual reduction of the mass loss during the observation period of 2005–2008 and 2004–2008, and exhibited positive mass balances in 2008, possibly resulting from increases of annual precipitation and decreases in mean annual air temperatures, especially the lowering of air temperatures and the notably increasing of precipitation during the ablation period in 2006–2008. However, the mass balances of the two glaciers differed considerably. The differences in mass balance between the glaciers appear closely related to local climatic factors (different local moisture recycling and different seasonal distributions of precipitation) and glacier topography (the leeward/windward slopes and different elevations of the accumulation and ablations zones). Interestingly, the mass balances in the final year of our study period (2007/2008) for these two glaciers are much more similar, although they differed during the first year (2005/2006), resulting from differences between their annual precipitation trends. Observations indicate that changes in either the air temperature or precipitation will drive mass balance changes for the two glaciers, and the changes in the mass balance will directly affect the local water resource. These findings will provide important data for hydrological modelling of glacierized catchments and local water resource management strategies.

Novel spirobisindane-containing thermally rearranged (TR) benzoxazole(spiroTR-PBO) membranes were prepared by thermal treatment of four newly synthesized spirobisindane-containing hydroxyl-polyimides (spiroHPIs). Transport properties of spirobisindane-containing polymers were investigated along with fractional free volume and density measurements, as well as molecular simulation analysis. The resulting spiroTR-PBOs exhibited high free volumes and superior mechanical properties in terms of elongation and tensile strength, and these findings were supported by molecular dynamic simulations. SpiroTR-PBO membranes containing hexafluoroisopropylidene moiety in the polymer backbone showed a six-fold increase in CO2 permeability, compared to that of the spiroHPI precursor. SpiroTR-PBO membranes showed strong potential to be applied in carbon capture and separation of gases because of their high gas permeability coupled with robust mechanical properties.

In this study, we sought a better understanding of how the hydrophilicity of a polymer affects the morphology and performance of membranes. Three types of polymer with different hydrophilicity solution systems were considered: poly(aryl ether ketone) bearing a hydroxyl group (PEK–OH-100) with N,N-dimethylformamide (DMF); poly(aryl ether ketone) bearing a 50% fraction hydroxyl group with DMF, and cardo poly(aryl ether ketone) with DMF. These systems were used to investigate the evolution of the morphology and variation in performance versus a change in the hydrophilicity of the polymer. In addition, the fundamental thermodynamic influence of the solution systems on the phase-inversion process was investigated by cloud-point measurement and Hansen solubility parameter theory to determine the role of polymer hydrophilicity on the stability of the polymer solution in humid surroundings. The performance of the membranes was tested via testing of the pure water flux, porosity, and rejection of bovine serum albumin (BSA) with respect to variations in the polymer hydrophilicity, evaporation time, relative humidity, and molecular weight of the polymer. The resulting optimal membrane exhibited a flux of 329.3 L m−2 h−1 and a 99.3% rejection of BSA at a relative humidity of 90% and an evaporation time of 3 s. The hydrophilic PEK–OH-100 membranes have promising applications in protein separation and the porous support of reverse-osmosis membranes and so on. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44701.

In this study, a cardo poly(aryl ether ketone) ultrafiltration membrane containing an N-chloramine functional group (PEK-N-Cl membrane) was easily obtained via exposure of a cardo poly(aryl ether ketone) ultrafiltration membrane (PEK-NH membrane) to dilute sodium hypochlorite solution. The chlorination process did not harm membrane performance. In addition, the PEK-N-Cl membrane was stable in both air and water. The PEK-N-Cl membrane exhibited excellent antimicrobial properties against both Gram-negative and Gram-positive bacteria (i.e. E. coli and Bacillus subtilis, respectively). The PEK-N-Cl membrane provided 94.2% and 100% reduction of E. coli and Bacillus subtilis, respectively, within 30 min of contact times. Moreover, nearly 100% of the E. coli was killed after 2 h during the filtration process for the PEK-N-Cl membrane. In addition, the water flux decreased by 42% for the PEK-N-Cl membrane compared to 77.6% for the PEK-NH membrane after filtration of the E. coli solution and incubation on LB nutrient agar plate, indicating that the PEK-N-Cl membrane enhibits antifouling. Furthermore, the PEK-N-Cl membrane is recyclable via subsequent exposure to a sodium hypochlorite solution.

Ultrathin films of organic networks on various substrates were fabricated through the solution-based molecular layer deposition (MLD) technique. The rigid tetrahedral geometries of polyfunctional amine and acyl chloride involved in the reaction ensure the continuity of the polymerization process. A linear increase in film thickness with respect to cycle number was observed by UV-vis adsorption, ellipsometry, and quartz crystal microbalance. The growth rate per MLD cycle is 1.6 nm, which can be controlled at the single molecular level. For the first time, we develop the MLD method on the top of hydrolyzed PAN substrate, resulting in nanofiltration (NF) membranes. The stepwise growth was monitored via attenuated total reflectance infrared studies. The separation performance of the obtained membrane for various solutes was sensitive to the terminated layers and number of cycles. The rejection of NH(2)-terminated membranes follows the order of CaCl(2)Na(2)SO(4)NaCl, while the order for COOH-capped surface is Na(2)SO(4)CaCl(2)NaCl. The absolute value of zeta potential for the MLD membranes decreases with the addition of deposition layers. The moderate water flux for the resulting membrane is due to the reduced porosity of the support as well as the low roughness and hydrophilicity of the membrane surface. This bottom-up process provides a promising approach for construction of long-term steady NF membranes with nanoscale dimensions.

A series of poly(arylene ether sulfone)s containing quaternized triptycene groups are synthesized through a chloromethylation reaction following a quaternization process. The resulting ionomers are soluble in polar aprotic solvents; thus, flexible, tough membranes could be prepared by solution casting. Novel anion exchange membranes based on these ionocmers are obtained by anion exchange with hydroxide ions. All anion exchange membranes show conductivities above 10(-2) S cm(-1) at room temperature. The highest hydroxide conductivity is 7.2 x 10(-2) S cm(-1), which is achieved by the anion exchange membrane with ion exchange capacity (IEC) = 2.61 mmol g(-1). Meanwhile, these anion exchange membranes have low water uptake and good dimensional stability even at high IEC values. For example, the membrane water uptake (IEC = 1.97 mmol g(-1)) is only 21% at room temperature, and the swelling ratio is 11%. The anion exchange membranes are stable in alkaline conditions. All the membranes have no significant change in 4 M NaOH solution at 25 degrees C after 30 days. All results suggest that these anion exchange membranes have potential application in alkaline fuel cells. (C) 2012 Elsevier B.V. All rights reserved.

A quaternary phosphonium and tertiary phosphorus functionalized microporous polymer was obtained via nickel(0)-catalyzed Yamamoto-type cross-coupling reaction. The integration ratio of signals (quaternary phosphonium to tertiary phosphorus atoms) was close to 3:2. The polymer networks were stable toward water, base, and acid, and indeed no change in surface area was observed even after the material was treated with 10 M HCl. The pore size distribution calculated by the Horvath–Kawazoe method indicated the presence of micropores with a mean width of about 0.7 and 1.4 nm. Their apparent BET specific surface areas can be tuned (from 650 to 980 m2 g–1) by changing the counteranions (Br– to F–). It displays high intrinsic catalytic activity for the reaction between epoxide and CO2 (yield: 98%, 1 atm). Pd nanoparticles supported on the polymer networks were also prepared, which exhibits high catalytic activity for cross-coupling reaction between 1-chlorobenzene and phenylboronic acid (yield: >95.8%).

A facile surfactant-based hexaalkylguanidinium ionic liquid (GIL)-mediated Suzuki coupling procedure has been developed using ligand-free Pd catalysts. The procedure involving the use of nanometric palladium micelles, is operationally simple and remarkably efficient for the coupling of aryl bromides or aryl chlorides with boronic acids in water. Furthermore, the GIL/H(2)O catalytic system was more stable than the tetrabutylammonium bromide/H(2)O catalytic system under basic conditions, enabling the recycling of the nano-Pd micelle catalysts.

A series of multi-block poly(arylene ether sulfone)s are synthesized via the copolymerization of bis(4-hydroxyphenol) sulfone, 3,3', 5,5'-tetramethylbiphenol and 4,4'-difluorodiphenyl sulfone. The resulting multi-block copolymers are brominated by using N-bromosuccinmide (NBS) as bromination reagent. The bromomethylated copolymer is solution cast to form clear, creasable films, and subsequent soaking of these films in aqueous trimethylamine to give benzyltrimethylammonium groups. The anion exchange membranes obtained by the solution hydroxide exchange with aqueous sodium hydroxide show varying degrees of ionic conductivity depending on their ion exchange capacity. The highest hydroxide conductivity 0.029 S cm(-1) is achieved with the QBPES-40 membrane having IEC value of 1.62 mequiv g(-1) at room temperature and 100% RH. The obtained anion exchange membranes also have good mechanical properties and dimensional stability, which greatly facilitates the preparation of a MEA and the cell operation. (C) 2011 Elsevier B.V. All rights reserved.

A series of cardo poly(aryl ether sulfone) copolymers bearing pendant hydroxyl ethyl groups (-CH(2)CH(2)OH) were synthesized from a new biphenol monomer 2-(2-hydroxyethyl)-3,3-bis(4-hydroxyphenyl)isoindolin-1-one (PPH-OH), 4,4'-biphenol(BP), and 4,4'-difluorodiphenylsulfone (DFDPS). Sulfonic acid groups were readily grafted to the copolymers by reaction of the hydroxyl group with 1,3-propanesultone. The resulting sulfonated copolymers SPES-C-X (where X refer to the content of PPH-OH in the bisphenol monomers) contain side chain sulfoalkyl groups (-CH(2)CH(2)-O-CH(2)CH(2)CH(2)SO(3)H). TEM photographs revealed that SPES-C-100 membrane exhibited characteristic hydrophilic/hydrophobic microphase separated morphology with small interconnected and hydrophilic clusters (1.5-2 nm). Such microphase separated morphology renders the membrane high proton conductivity of 0.056 S/cm (IEC = 1.41 mequiv./g), and low dimensional changes of SPES-C-100 at room temperature. SPES-C-X membranes exhibited the methanol permeability in the range of 13.8-5.3 x 10(-8) cm(2)/s, which were much lower than those of SBPES (8.7 x 10(-7) cm(2)/s) and Nafion 117 (2.4 x 10(-7) cm(2)/s). (C) 2010 Elsevier B.V. All rights reserved.

A series of quaternized poly(arylene ether sulfone)s containing up to two pendant quaternary ammonium groups per repeat unit was prepared by cesium carbonate mediated direct aromatic nucleophilic substitution polycondensation of 2,2'-dimethylaminemethylene-4,4'-biphenol (DABP), 4.4'-biphenol (BP) and 4,4'-difluorodiphenylsulfone (DFDPS), followed by reaction with iodomethane. The anion exchange membranes formed from these polymers showed conductivities above 10(-2) S cm(-1) at room temperature with a hydroxide conductivity of 6.5 x 10(-2) S cm(-1) for QNPS-OH-80. At the test of alkaline stability, these poly(arylene ether sulfone) ionomers were more stable than our previous reported partially fluorinated poly(arylene ether sulfone) ionomers under highly basic conditions. (C) 2010 Elsevier B.V. All rights reserved.

Novel cardo poly(aryl ether sulfone)s containing pendent -[CH2CH2NMe3]+OH-, or -[CH2CH2CH2NMe3]+OH- groups, and partially fluorinated cardo poly(aryl ether sulfone) containing pendent -[CH2CH2CH2NMe3]+OH- groups were synthesized and examined with the focus of understanding how the polymer chemical structure affects their morphology, ion conductivity and alkaline stability. The resulting quaternized polymers exhibited outstanding solubility in polar aprotic solvents. The partially fluorinated cardo poly(aryl ether sulfone)s (PES-PF-OH) with ion-exchange capacity of 1.44 meg g(-1) displayed the highest ion conductivities, varied from 3.0 x 10(-2) to 4.1 x 10(-2) S cm(-1) over the range 20-60 degrees C. TEM revealed that PES-PF-OH membrane exhibited a distinct phase-separated morphology comprised of interconnected ionic clusters in size of 1-2 nm. The studies on alkaline stability of the membranes revealed that the PES-PF-OH polymer was not stable under strong basic conditions. The quarternized polymers containing pendent -[CH2CH2NMe3]+OH-, or -[CH2CH2CH2NMe3]+OH- groups mainly underwent Hofmann elimination and S(N)2 substitution reaction. (C) 2010 Elsevier Ltd. All rights reserved.

A new biphenol monomer, 2-(2-(dimethylamino)ethyl)-3,3′-bis(4-hydroxyphenyl)isoindolin-1-one (CPPH), was easily prepared by the reaction of phenolphthalein with N,N-dimethylethane-1,2-diamine. Novel polyampholyte, sulfonated poly(aryl ether sulfone)s with pendent alkyl ammonium groups PESQ-x-y, were prepared by copolymerization of CPPH, 4,4′-biphenol, 3,3′-disulfonated-4,4′-dichlorodiphenyl sulfone, and 4,4′-dichlorodiphenyl sulfone, and this was followed by reaction with iodomethane. PESQ-x-y was able to form uniform and tough membranes by simple solution casting. Moreover, the material exhibited a low water uptake as well as a decent dimensional stability in water, even at high temperature (e.g. 100 °C), as a result of the strong electrostatic interactions between the alkyl ammonium and sulfonic acid groups. The PESQ-10-50 copolymer membrane with an ion-exchange capacity (IEC) of 1.65 mequiv./g, displayed a lower water uptake (58.9%), but a higher proton conductivity (0.082 S/cm) than a PES-40 membrane without alkyl ammonium groups (IEC = 1.67 mequiv./g, WU = 85.4%, σ = 0.069 S/cm) at 20 °C.

A novel locally and densely sulfonated dianhydride with four sulfonic acid groups, 1,6,7,12-tetra[4-(sulfonic acid)phenoxylperylene-3,4,9,10-tetracarboxylic dianhydride (SPTDA), was successfully synthesized by direct sulfonation of the parent dianhydride. 1.6,7,12-tetraphenoxyperylene-3,4,9,10-tetracarboxylic dianhydride (PTDA). Sulfonated copolyimides were prepared from SPTDA, nonsulfonated dianhydride 4,4'-binaphthyl-1,1',8,8'-tetracarboxylic dianydride, 4,4'-diaminodiphenyl ether (a) or dodecane-1,12-diamine (b). The synthesized copolymers, with the -SO3H group on the polymer side chain, possess high molecular weights and high viscosities, and they form tough, flexible membranes. The copolymer membrane with an ion exchange capacity of 2.69 mequiv.g(-1) had a proton conductivity of 0.126 S cm(-1) at 20 degrees C and 0.292 S cm(-1) at 100 degrees C; the latter is much higher than that of Nafion (R) 117 under the same conditions. The mechanical properties of the copolymer membranes were almost unchanged after accelerated water stability testing at 140 degrees C for 100 h; this indicates excellent hydrolytic stability of the synthesized copolyimides. (C) 2009 Elsevier B.V. All rights reserved.

Poly(arylene ether sulfone)s were functionalized with quaternary guanidinium groups in order to investigate their properties as novel polymeric hydroxide exchange membrane materials. The quaternized polymers were synthesized via chloromethylation of poly(arylene ether sulfone)s, followed by reactions with pentamethylguanidine. The resulting quaternized polymers PSGCl-x (where x represents the number of the quaternary guanidinium groups/repeat units) presented an elevated molecular weight and exhibited an outstanding solubility in polar aprotic solvents. Consequently flexible and tough membranes of PSGCl-x with varying ionic content could be prepared by casting from the DMSO solution. Novel anion exchange membranes, PSGOH-x, were obtained by an anion exchange of PSGCl-x with 1 M NaOH at room temperature. The membranes displayed a high ionic conductivity and an excellent chemical stability. The obtained alkaline anion exchange membranes (AEMs) showed conductivities almost above 10−2 S cm−1 at room temperatu...

Novel guanidinium ionic liquid-grafted rigid poly(p-phenylene) (PPPIL) microspheres have been developed for metal scavenging and catalysis. The noble-metal nanoparticles supported on the microspheres surface can be used as efficient heterogeneous catalysts. The combination of nanoparticles and ionic liquid fragments on the microsphere surfaces enhance the activity and durability of the catalyst. The PPPILPd(0) catalyst has been tested in the Suzuki cross-coupling reaction, and exhibits much higher catalytic activity than Pd catalysts supported on porous polymer matrices. The PPPILPd(0) catalyst can be recycled at least for nine runs without any significant loss of activity. The present approach may, therefore, have potential applications in transition-metal-nanocatalyzed reactions.

The synthesis and characterization of carbon-coated ferromagnetic nanoparticles that organize into 1-D assemblies of micrometer-sized ferromagnetic chains is described. A controlled aromatization and carbonization of glucose under hydrothermal reaction conditions enabled the preparation of carbonaceous surfactants that were used as shells for the coating of ferromagnetic Fe(3)O(4) nanospheres with a uniform size distribution. Under controlled experimental conditions, it was, for the first time, demonstrated that glucose could be employed as the carbon source in the preparation of continuous 1-D carbon nanoparticle chains with magnetic nanosphere inclusions. The functional groups on the carbon surface will facilitate the linkage of functional groups or catalytic species to the surface in future application. The salient feature of the reported method was the assembly of magnetic nanospheres under hydrothermal reaction conditions in the absence of external fields.

A new bisphenol monomer, 2,2′-dimethylaminemethylene-4,4′-biphenol (DABP), was easily prepared by Mannich reaction of dimethylamine and formaldehyde with 4,4′-biphenol. Novel partially fluorinated poly(arylene ether sulfone)s with pendant quaternary ammonium groups were prepared by copolymerization of DABP, 4,4′-biphenol, and 3,3′,4,4′-tetrafluorodiphenylsulfone, followed by reaction with iodomethane. The resulting copolymers PSQNI-x (where x represents the molar fraction of DABP in the feed) with high molecular weight exhibited outstanding solubility in polar aprotic solvents; thus, the flexible and tough membranes of PSQNI-x with varying ionic content could be prepared by casting from the DMAc solution. Novel anion exchange membranes, PSQNOH-x, were obtained by an anion exchange of PSQNI-x with 1 N NaOH. All PSQNOH-x membranes showed conductivities above 10−2 S cm−1 at room temperature, for example, the hydroxide conductivity of PSQNOH-90 achieved to 8.4 × 10−2 S cm−1, which was thus comparable to the p...

A sulfonated poly[bis(benzimidazobenzisoquinolinones)] (SPBIBI) possessing a conjugated pyridinone ring was shown to be effective for dispersing multiwalled carbon nanotubes (MWCNTs) in DMSO. The dispersions in which the SPBIBI to MWCNTs mass ratio was 4:1 demonstrated the highest MWCNTs concentrations, i.e., 1.5-2.0 mg mL(-1), and were found to be stable for more than six months at room temperature. Through casting of these dispersions, MWCNTs/SPBIBI composite membranes were successfully fabricated on substrates as proton exchange membranes for fuel cell applications and showed no signs of macroscopic aggregation. The properties of composite membranes were investigated, and it was found that the homogeneous dispersion of the MWCNTs in the SPBIBI matrix altered the morphology structures of the composite membranes, which lead to the formation of more regular and smaller cluster-like ion domains.