Stilbenedisulfonic Acid Disodium Salt Research Articles

A Fluorescence Kinetic-Based Aptasensor Employing Stilbene Isomerization for Detection of Thrombin

It is important to detect thrombin due to its physiological and pathological roles, where rapid and simple analytical approaches are needed. In this study, an aptasensor based on fluorescence attenuation kinetics for the detection of thrombin is presented, which incorporates the features of stilbene and aptamer. We designed and synthesized an aptasensor by one-step coupling of stilbene compound and aptamer, which employed the adaptive binding of the aptamer with thrombin to cause a change in stilbene fluorescence attenuation kinetics. The sensor realized detection of thrombin by monitoring the variation in apparent fluorescence attenuation rate constant (kapp), which could be further used for probing of enzyme–aptamer binding. In comprehensive studies, the developed aptasensor presented satisfactory performance on repeatability, specificity, and regeneration capacity, which realized rapid sensing (10 s) with a limit of detection (LOD) of 0.205 μM. The strategy was successful across seven variants of thrombin aptasensors, with tunable kapp depending on the SITS (4-Acetamido-4′-isothiocyanato-2,2′-stilbenedisulfonic acid disodium salt hydrate) grafting site. Analyte detection mode was demonstrated in diluted serum, requiring no separation or washing steps. The new sensing mode for thrombin detection paves a way for high-throughput kinetic-based sensors for exploiting aptamers targeted at clinically relevant proteins.

Membrane properties of sulfonated polytriazoles with molecular branching

AbstractThe incorporation of branching units in the polymer is beneficial in improving many of the polymer properties. This article deals with the synthesis of branched sulfonic acid–based copolytriazoles (PTHPSH‐XX) to prepare freestanding membranes. The copolymers were synthesized by the click reaction of 1,4‐bis(prop‐2‐ynyloxy)benzene, 1,3,5 tris[2‐trifluoromethyl‐4(4‐azidophenyl) phenoxy]benzene (B3), and 4,4′‐diazido‐2,2′‐stilbene disulfonic acid disodium salt. The chemical constructions of the subsequent copolymers were established by Fourier‐transform infrared spectroscopy and proton nuclear magnetic resonance spectroscopy. The copolymers showed high thermal stability, low water absorption, and outstanding structural robustness in their hydrated state. The presence of branching segments (B3) in the copolymers contributed to improved peroxide radical resistance and proton conductivity (71–192 mS/cm measured at 90°C) in comparison with their linear analogs. In addition, the membranes exhibited reasonably good set of mechanical properties (TS = 71–53 MPa, YM = 2.76–2.33 GPa). The membranes exhibited phase‐separated morphology in their transmission electron microscope images with ionic domains of 20–160 nm.

The role of voltage-gated chloride channels in the epileptogenesis of temporal lobe epilepsy.

BackgroundTemporal lobe epilepsy (TLE) is the most common intractable epilepsy in adults, and elucidation of the underlying pathological mechanisms is needed. Voltage-gated chloride channels (ClC) play diverse physiological roles in neurons. However, less is known regarding their functions in the epilepogenesis of TLE.MethodsClC-mediated current and the spontaneous inhibitory synaptic currents (sIPSC) in hippocampal neurons of epileptic lesions were investigated by electrophysiological recording. The EEG data were analyzed by Z-scored wavelet and Fourier transformations. The expression of ClC-3, a member of ClC gene family, was detected by immunostaining and western blot.FindingsClC-mediated current was increased in the hippocampal neurons of chronic TLE mice. Application of chloride channel blockers, NPPB (5-Nitro-2- [3-phenylpropylamino] benzoic acid) and DIDS (4,4’-Diisothiocyanato-2,2’-stilbenedisulfonic acid disodium salt) reduced ClC-mediated current and increased inhibitory synaptic transmission in TLE mice. NPPB and DIDS reduced the seizure frequency and the average absolute power of ictal high-frequency oscillations (HFOs, 80-500 Hz) in TLE mice. In addition, both drugs induced outwardly rectified currents, which might be tonic inhibitory currents in the hippocampal neurons of TLE patients. Furthermore, the expression of ClC-3 was increased in the hippocampus of TLE mice and patients and positively correlated with both the absolute power and number of ictal HFOs per seizure in the sclerotic hippocampus.InterpretationThese data suggest that ClC participate in the epilepogenetic process of TLE and the inhibition of ClC may have anti-epileptic effect.FundingThis work was supported by National Natural Science Foundation of China (No. 81601143, No. 81771217).

Effect of sulfonic acid‐functionalized polysilsesquioxane on new semifluorinated sulfonated polytriazole composites and investigation of proton exchange membrane properties

AbstractA new semifluorinated sulfonated copolytriazole is synthesized, maintaining a particular degree of sulfonation of 80% following the click reaction of two terminal azides 1,4‐bis‐[{2′‐trifluromethyl 4′‐(4″‐azidophenyl)phenoxy}]phenyl, and 4,4′‐diazido‐2,2′‐stilbenedisulfonic acid disodium salt with equal molar amounts of two dialkyne monomers namely, 1,3‐diethynylbenzene and 3,5‐bis(prop‐2‐ynyloxy)benzoic acid and designated as PTEHCSH‐80. Further, the copolytriazole is used to prepare polymer composites employing the sol‐gel reaction of the starting precursor sol 3‐(trihydroxylsilyl) propane‐1‐sulfonic acid. The weight percentage (wt%) of the filler is varied from 0 to 10 wt%, and a series of polymer composite films are prepared and abbreviated as PTEHCSH‐80/X (where X is wt% of the filler, X = 0. 2.5, 5.0, 7.5, 10.0). All the polymer composites are characterized through FTIR spectroscopic techniques. The composite films revealed various desirable properties such as high thermochemical and dimensional and mechanical stabilities in their corresponding acid form. Moreover, the composites exhibited proton conductivities ranging from 62 to 98, 117 to 182, and 131 to 195 mS/cm at three different temperatures 30°C, 80°C, and 90°C, respectively, in a hydrated state.

Synthesis of 2,2′-hindered pyridine containing semifluorinated polytriazoles and investigation for low-temperature proton exchange membrane application with enhanced oxidative stability

A series of new sulfonated copolytriazoles were prepared from a novel fluorinated diazide monomer with pyridine moiety to enhance both the oxidative stability and proton conductivity of proton exchange membranes. These proton donor–acceptor based copolymers and homopolymers were synthesized by click cycloaddition polymerization of the dialkyne monomer 1,2,4,5-tetrafluoro-3,6-bis(prop-2-yn-1-yloxy)benzene (TFAK) with or without the pyridine containing diazide monomer 2,2′-bis(4-(4-azidophenoxy)-3-(trifluoromethyl)phenyl)pyridine (PYFAZ) and the sulfonated diazide monomer 4,4′-diazido-2,2′-stilbenedisulfonic acid disodium salt (DSSAZ). 1H, 13C, and 19F NMR, in addition to FTIR analyses, confirm the formation of polytriazoles with a graded degree of sulfonation between 70% and 100%. The solution cast membranes were flexible and showed high chemical, thermal and mechanical properties. Inclusion of pyridine moiety proved to play a significant role in increasing peroxide stability by quenching hydroxyl and hydroperoxide radicals and forming pyridine-N-oxide, which was analyzed by EPR and FTIR spectroscopy. The presence of pyridine moiety also enhanced proton conductivity owing to the presence of the weakly basic nitrogen in pyridine that acts as a proton hopping site. AFM and HR-TEM images of the membranes indicated the formation of phase-separated morphology and that became more pronounced with the increase in the degree of sulfonation. The membranes obtained from PYFTSH-90 copolymer exhibited proton conductivity of 125 mS cm−1 at 80 °C, which is comparable to Nafion-117. The proton conductivity of PYFTSH-90 was further increased to 139 mS cm−1 at 90 °C. Thus, three significant objectives have been fulfilled in this work, namely (i) high proton conductivity, (ii) high hydrolytic stability, and (iii) high peroxide stability. These properties demonstrate that these copolymer membranes are potentially highly suitable for application in low-temperature proton exchange membrane fuel cell (PEMFC).

Synthesis and characterization of star-shaped sulfonated new poly(ether triazole)s: Proton exchange membrane properties

Several star-shaped sulfonated poly(ether triazole)s abbreviated as PTAPSH-XX was prepared by Cu (I) catalyzed click polymerization of a mixture of a new tri-azide monomer namely, 4,4-tris[3-trifluoromethyl-4(4-azidophenoxy)phenyl]biphenyl (PGZ) (B3) and 4,4′-diazido-2,2′-stilbene disulfonic acid disodium salt (DADSDB) with an equimolar amount 4,4′-(propane-2,2-diyl) bis((prop-2-ynyloxy)benzene) (BPEBPA). The degree of sulfonation of the prepared copolymers was varied by changing the molar ratio of DADSDB in the polymer feed. The monomer and copolymers were characterized by FTIR and NMR spectroscopic techniques. The salt form of the branched copolymers was converted into flexible membranes by solution casting technique using dimethyl sulfoxide (DMSO) as solvent and was converted to their acid form by acidification in 1.5 M H2SO4. The introduction of the branching unit largely governs the physicochemical properties and proton conductivity of the membranes. The polymers displayed desirable set of properties required proton exchange membrane applications like high thermal stability (Td10 ~ 259–290 °C), low water uptake and excellent dimensional integrity. The membranes also displayed improved mechanical properties (TS = 51 to 73 MPa, YM = 2.07 to 2.37 GPa), enhanced oxidative stability and high proton conductivity (44 to 102 mS cm−1 at 80 °C). The TEM images of the PTAPSH-XX membranes revealed excellent phase segregated morphology with the formation of ionic clusters within 15 to 90 nm.

Synthesis and characterization of new sulfonated copolytriazoles and their proton exchange membrane properties

ABSTRACTThis work reports the synthesis and characterization of a series of new sulfonated copolytriazoles. The polymers were prepared by CuI catalyzed 1,3‐cycloaddition reaction of an equimolar amount of a dialkyne monomer, 1,3‐diethynylbenzene and a mixture of two diazide monomers, namely, 4,4′‐diazidodiphenyl ether and 4,4′‐diazido‐2,2′‐stilbenedisulfonic acid disodium salt. The copolymers showed high inherent viscosity indicating the formation of high molar mass product. The copolymers were characterized by Fourier transform infrared and proton nuclear magnetic resonance spectroscopic techniques. The copolymer membranes displayed moderate water uptake, high dimensional, mechanical, and thermal stability. Transmission electron microscopy micrographs displayed excellent phase‐separated morphology along with very fine ionic clusters. The copolymer PTEOSH‐90 (90% degree of sulfonation) showed much higher proton conductivity value which is up to 196 mS cm−1 at 80 °C in completely hydrated condition compared to that of Nafion (165 mS cm−1). © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48514.

Extracellular lysine 38 plays a crucial role in pH-dependent transport via human monocarboxylate transporter 1

Human monocarboxylate transporters (hMCTs) are expressed in many tissues and mediate the transport of various substrates across the plasma membrane. Among hMCTs, hMCT1–4 cotransport H+ with monocarboxylates such as pyruvate and l-lactate, implying that these proteins recognize both substrate and H+. However, the mechanism of translocation, and particularly that of hMCT1 pH-dependent transport, remains largely unknown. This study aimed at identifying residues involved in the pH dependence of hMCT1 using a combination of amino acid-modifying reagents, site-directed mutagenesis in a Xenopus laevis oocyte expression system, and homology modeling. We showed that diethyl pyrocarbonate (DEPC), phenylglyoxal (PGO), and 4,4′-diisothiocyanato-2,2′-stilbenedisulfonic acid disodium salt (DIDS), which react with histidine, arginine, and lysine residues respectively, all inhibited hMCT1 activity. Since DEPC, PGO, and DIDS are membrane impermeable reagents, we mutated to other residues individual histidine, arginine, and lysine residues located within the extracellular regions of hMCT1. Analyses of these mutants demonstrated that except for K38, the extracellular basic residues of hMCT1 were not involved in its transport activity and pH dependence. Moreover, analyses of various mutants in which K38 was substituted for another residue and of an hMCT1 homology model focusing on the location of K38 in the three-dimensional structure delineated the mechanism of hMCT1 pH dependence. Collectively, our data indicate that K38 plays an essential role in hMCT1 transport activity. We would like to propose a mechanism whereby K38 is positioned within a hydrophobic and narrow cavity that is part of the transport pathway, and regulates pH-dependent gating of hMCT1.

Synthesis and characterization of chemically stable sulfonated copoly(triazole imide)s with high proton conductivity

The synthesis and characterization of a series of new sulfonated copoly(triazole imide)s (PTPQSH‐XX) are reported in this work. The PTPQSH‐XX with different degree of sulfonation (DS) were prepared by click polymerization of equimolar amounts of a diimide‐based dialkyne monomer, namely bis‐N,N′‐(prop‐2‐ynyl)pyromellitic diimide (TP) and a mixture of two different diazide monomers (one sulfonated, 4,4‐bis[3′‐trifluoromethyl‐4′{4‐azidobenzoxy} benzyl] biphenyl, and another nonsulfonated, 4,4′‐diazido‐2,2′‐stilbene disulfonic acid disodium salt [SAZ]), in different molar ratios. The copolymers showed high inherent viscosity (1.12–1.28 dL/g) in n‐methyl pyrrolidone (NMP) indicating the formation of high molar masses. Freestanding membranes were prepared from these copolymers by solution casting method. DS of the copolymers was determined from 1H NMR signal intensities, and the values were in good agreement with the quantity of SAZ monomer used in polymer feed, indicating the successful incorporation of the sulfonated monomer. The copolymers exhibited high thermal and mechanical stabilities. The PTPQSH‐80 membrane showed proton conductivity as high as 178 mS/cm at 90°C with good oxidative and hydrolytic stability. Cross‐sectional transmission electron microscope micrographs of the membranes indicated phase segregated morphology along with interconnected hydrophilic domains with dimension in the range 15–150 nm. POLYM. ENG. SCI., 59:2279–2289, 2019. © 2019 Society of Plastics Engineers

Electromechanical Decoupling by Porous Aerogel Conducting Polymer

In the field of biointerface electronics, electromechanical decoupling—electrical performance independent of mechanical deformation—can ensure reliability of measured signals, which is critical in stable electrode. Herein, Chen et al. report such a decoupled and stretchable conductive polymer foam.

Hairpin probes based click polymerization for label-free electrochemical detection of human T-lymphotropic virus types II

A novel, simple, and label-free amplification electrochemical impedance method for quantitative detection of Human T-lymphotropic virus types II(HTLV-II) via click chemistry-mediated of hairpin DNA probes (hairpins) with polymers was developed. The hairpins were firstly attached to the gold electrode surface by an S-Au bond, the azido terminals of hairpins were close to the electrode surface, which make it difficult to be approached. After hybridizing with HTLV-II, the hairpins were unfolded and experienced a big configuration change, which made the azido terminals of the hairpins available to conjugate with alkynyl-containing polymer, called P(DEB-DSDA), formed by 1,4-diacetylenebenzene (DEB) and 4,4′-Diazido-2,2′-stilbenedisulfonic acid disodium salt tetrahydrate (DSDA) via Cu(I)-catalyzed azide-alkyne cycloaddition (CuAAC). With amount of P(DEB-DSDA) conjugated with the hairpin probes via click polymerization, its electrochemical signal can have a great amplification. Under optimized experimental conditions, this new probe showed a low detection limit of 0.171 pM with a good liner in the range of 1 pM-1 nM. Meanwhile, the biosensor also exhibited good selectivity and reliability in detection of real serum samples, indicating that it has great application potential in clinical DNA diagnosis and detection.

Synthesis and Characterization of Highly Proton Conducting Sulfonated Polytriazoles

This article describes the synthesis and characterization of highly sulfonated polytriazole copolymers (PTSQSH-I to IV) with IECw values ranging from 2.41 to 3.49 mequiv g–1. The copolymers were synthesized by click reaction between equimolar amount of a dialkyne monomer, potassium 2,5-bis(2-propyn-1-yloxy)benzenesulfonate, and a mixture of two different diazide monomers, 4,4-bis[3′-trifluoromethyl-4′(4-azidobenzoxy)benzyl]biphenyl and 4,4′-diazido-2,2′-stilbene disulfonic acid disodium salt. The copolymers were characterized by Fourier transform infrared and NMR spectroscopy techniques. The membranes were prepared by dissolving the salt form of the copolymers in dimethyl sulfoxide. The copolymers showed high thermal, mechanical, and oxidative stabilities, and the acidified membranes showed very high proton conductivity (43–173 and 132–304 mS cm–1 at 30 and 80 °C, respectively). Transmission electron microscopy images confirmed the formation of well-phase-separated morphology with interconnected hydrophilic domains (20–150 nm).

New crosslinked sulfonated polytriazoles: Proton exchange properties and microbial fuel cell performance

The synthesis, characterization and establishment of the structure-property relationship of a series of new semifluorinated sulfonated polytriazoles (PTCTSH-XX) with varying degrees of sulfonation are described. The polymers were synthesized by the click polymerization reaction of a mixture of two diazide monomers, the non-sulfonated diazide monomer 4,4-bis[3-trifluoromethyl-4(4-azidophenoxy) phenyl]benzene (TAZ) and the sulfonated diazide monomer 4,4′-diazido-2,2′-stilbenedisulfonic acid disodium salt (SAZ), with an equimolar amount of the dialkyne monomer 3,5-bis(prop-2-ynyloxy)benzoic acid (BPBA). The polytriazoles were characterized by 1H and 13C NMR spectroscopy. All the polymers showed good solubility in selected polar aprotic organic solvents along with excellent film forming ability. The TEM micrographs of these polymers exhibited a uniformly phase separated morphology. The polymers showed very high proton conductivity and the values were within the range of 15–67 mS cm−1 at 30 °C, 38–163 mS cm−1 at 80 °C and 42–176 mS cm−1 at 90 °C in hydrated condition. The pristine polymers were crosslinked with poly(vinyl alcohol) and their PEM properties were also investigated. The crosslinked films showed lower water uptake and dimensional swelling and improved oxidative stability in comparison to the pristine membranes. The microbial fuel cell performance of both pristine and crosslinked membranes was also investigated.

Comb-shaped polysulfones containing sulfonated polytriazole side chains for proton exchange membranes

Comb-shaped polysulfone copolymers were synthesized by the click reaction, copper(I) catalyzed azide-alkyne 1,3-dipolar cycloaddition, using polysulfone having azidomethyl side group (PSf-N3) and sulfonated polytriazole having one ethynyl chain-end group. PSf-N3 was prepared by the substitution reaction of polysulfone through chloromethylation followed by azidation, and sulfonated polytriazoles having one ethynyl chain-end group was synthesized via the click reaction using 1,4-diethynylbenzene and 4,4′-diazido-2,2′-stilbenedisulfonic acid disodium salt tetrahydrate with CuI followed by end-capping process. Tough, flexible, and transparent membranes could be prepared by solution casting from the comb-shaped polysulfone copolymers and ion exchange capacity (IEC) of the resulting membranes could be controlled by changing the chain length of the sulfonated polytriazoles. The comb-shaped polysulfone membranes showed enhanced physicochemical stability and significantly higher proton conductivity when compared with a sulfonated poly(arylene ether sulfone) (SPAES) membrane having a similar IEC due to the distinct hydrophilic-hydrophobic phase separated morphology. The fuel cell performance of membrane electrode assembly with the comb-shaped polysulfone membrane is superior to those with the SPAES and Nafion-212 membranes at the various operating conditions.

Hydroquinone Based Sulfonated Copolytriazoles with Enhanced Proton Conductivity

AbstractA series of new fluorinated sulfonated copolytriazoles (PTHQSH‐XX) with ion exchange capacity (IECw) values ranging from 1.66 to 2.82 meq g−1 are prepared via cuprous ion catalyzed azide‐alkyne click polymerization reaction between 1,4‐bis(prop‐2‐ynyloxy)benzene, 4,4′‐diazido‐2,2′‐stilbene disulfonic acid disodium salt (SA), and 4,4‐bis[3′‐trifluoromethyl‐4′(4‐azidobenzoxy) benzyl] biphenyl (QAZ). The degree of sulfonation of the copolytriazoles is adjusted between 60% and 90% by varying the molar ratio of sulfonated monomer (SA) to the nonsulfonated monomer (QAZ). The structure of the copolytriazoles is characterized by Fourier transform infrared and NMR spectroscopy. The solution‐cast membranes of these copolymers exhibit high thermal, mechanical, oxidative and hydrolytic stability, and high proton conductivity (19–142 mS cm−1 at 80 °C and 22–157 mS cm−1 at 90 °C). Transmission electron microscopy confirms the formation of good phase separated morphology with ionic clusters in the range of 15–145 nm.

Flexible Diazide Based Sulfonated Polytriazoles and Their Proton Exchange Membrane Properties

The preparation, characterization, and property evaluation of a series of new semifluorinated polytriazoles (PTEHSH‐XX) with various degrees of sulfonation is described. The polymers are synthesized by the click polymerization reaction of a mixture of a new diazide monomer, 1,4‐bis‐[{2′‐trifluromethyl 4′‐(4″‐azidophenyl)phenoxy}]phenyl, and a sulfonated monomer, 4,4′‐diazido‐2,2′‐stilbenedisulfonic acid disodium salt, with an equimolar amount of a dialkyne monomer, 1,3‐diethynylbenzene. The polytriazoles are characterized by Fourier transform infrared spectroscopy (FTIR) and NMR spectroscopic techniques. The polytriazoles show good solubility in selective organic solvents and film forming ability. The films prepared from these polymers show high thermal and chemical stability, low water uptake, high dimensional stability, and excellent mechanical properties. The transmission electron microscopy images of these polymers exhibit a uniformly phase separated morphology. The polymers show very high proton conductivity and the values are within the range of 27–118 mS cm−1 at 30 °C, 53–225 mS cm−1 at 80 °C, and 58–235 mS cm−1 at 90 °C in hydrated condition. image

Hexafluoroisopropylidene based sulfonated new copolytriazoles: investigation of proton exchange membrane properties

Abstract A series of novel sulfonated polytriazole copolymers (PTFOSH-XX) was successfully prepared by the click reaction of 4,4′-(perfluoropropane-2,2-diyl)bis((prop-2-ynyloxy)benzene (TF), 4,4′-diazido-2,2′-stilbene disulfonic acid disodium salt (SAZ) and 4,4′-diazidodiphenyl ether (OAZ). The copolymers were characterized by Fourier transform infrared (FTIR) and proton nuclear magnetic resonance (NMR) spectroscopy. The copolymers showed high mechanical, thermal and oxidative stability and low swelling. The phase separated morphology of the membranes was confirmed from transmission electron microscopy (TEM). The membranes showed proton conductivity as high as 110 and 122 mS cm−1 at 80 and 90°C, respectively depending on the polymer repeat unit structure.

Synthesis and performance study of a novel sulfonated polytriazole proton exchange membrane

Sulfonated polytriazole (SPTA) proton exchange membranes (PEMs) with a series of sulfonation degrees was synthesized based on click chemistry from a rigid diazide monomer, 4,4′-bis(azidomethyl)-1,1′-biphenyl (BAMB), with 2,2-bis[(4-propargyloxy)phenyl]propane (BPBPA) and 4,4′-diazido-2,2′-stilbenedisulfonic acid disodium salt (DSDA). The structure of the copolymers was characterized by nuclear magnetic resonance (NMR) and gel permeation chromatography (GPC). As a result of the introduction of rigid biphenyl structure and the ionic interaction between triazole rings and sulfonic acid groups, the SPTA membranes exhibited higher water uptake and lower swelling ratio compared to NRE211 membrane, indicating excellent dimensional stability. AC impedance revealed that the proton conductivity of SPTA membranes ranged from 2.5 to 35 mS/cm at 30 °C and 13–105 mS/cm at 80 °C. Besides, the membranes have high thermal and oxidative stability, good mechanical property, and low methanol permeability as well.

Synthesis, characterization and investigation of proton exchange properties of sulfonated polytriazoles from a new semifluorinated diazide monomer

This work describes the synthesis and characterization of a new series of semifluorinated sulfonated polytriazole copolymers (PTATSH‐XX) with varying degree of sulfonation and higher IEC. The copolymers have been prepared by click reaction using a combination of diazide monomers; a newly synthesized diazide monomer namely 4,4‐bis[3‐trifluoromethyl‐4(4‐azidophenoxy)phenyl]benzene (TAZ) and a commercially available diazide monomer namely 4,4′‐diazido‐2,2′‐stilbenedisulfonic acid disodium salt (DADSDB) with a bis‐alkyne monomer namely 4,4′‐(propane‐2,2‐diyl)bis((prop‐2‐ynyloxy)benzene) (BPEBPA). The copolymers are well characterized by FTIR and NMR spectroscopy and have exhibited good solubility and film forming abilities along with good thermal and chemical stability, low water uptake, good dimensional stability and high mechanical properties. The TEM micrographs of the copolymer membranes show good phase separated morphology with cluster size in the range 10–60 nm. The proton conductivity values of the copolymer membranes are found in the range of 15–90 mS cm−1 at 80°C and 16–97 mS cm−1 at 90°C. POLYM. ENG. SCI., 57:312–323, 2017. © 2016 Society of Plastics Engineers

Cross-Linked Sulfonated Poly(arylene ether sulfone) Membranes Formed by in Situ Casting and Click Reaction for Applications in Fuel Cells

Sulfonated poly(arylene ether sulfone) membranes with cross-linked structures (C-SPAES) were simply prepared by simultaneously casting and heating the polymer solutions composed of sulfonated poly(arylene ether sulfone) with azidomethyl side groups (SPAES-N3), cross-linkers such as 1,4-diethynylbenzene and 4,4′-diazido-2,2′-stilbenedisulfonic acid disodium salt tetrahydrate, and a click reaction catalyst such as CuBr and N,N,N′,N″,N″-pentamethyldiethylenetriamine in N,N-dimethylacetamide, where SPAES-N3 were prepared by the substitution of sulfonated PAES (SPAES) through chloromethylation followed by azidation reaction. C-SPAES membranes obtained using the optimum amount of the cross-linkers showed much improved chemical and physical stabilities and mechanical strength compared with linear SPAES membrane. Since the cross-linked structures were formed by the cross-linker having sulfonic acid groups, C-SPAES membranes showed higher ion exchange capacity and proton conductivity than the linear SPAES membrane...