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Achieving high ionic conductivity, wide voltage window, and good mechanical strength in a single material remains a key challenge for polymer-based electrolytes for use in solid-state supercapacitors (SCs). Herein, we report cross-linked composite gel polymer electrolytes (CGPEs) based on multi-cross-linkable H-shaped poly(ethylene oxide)–poly(propylene oxide) (PEO-PPO) tetrablock copolymer precursors, SiO2 nanoparticles, and 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, an ionic liquid (IL). Self-standing CGPE membranes with a high IL content were prepared using in situ cross-linking reactions between the silane groups present in the precursor and the SiO2 surface. The incorporation of an optimal amount of SiO2 increased the cross-linking density of the resulting CGPE while reducing polymer-chain ordering and, consequently, increasing both ionic conductivity and mechanical strength. As a result, the CGPE with 0.1 wt % SiO2 exhibited a high ionic conductivity (2.22 × 10–3 S cm–1 at 25 °C), good tensile strength (453 kPa), and high thermal stability up to 330 °C. Finally, an all-solid-state SC assembled with the prepared CGPE showed a high operating voltage (3 V), a large specific capacitance (103.9 F g–1 at 1 A g–1), and excellent durability (94% capacitance retention over 10,000 charge/discharge cycles), which highlights its strong potential as a solid-state electrolyte for SCs.

Carbon monoxide (CO) is a cardioprotectant and potential cardiovascular therapeutic agent. Human cardiac fibroblasts (HCFs) are important determinants of myocardial structure and function. Large-conductance Ca2+-activated K+ (BK) channel is a potential therapeutic target for cardiovascular disease. We investigated whether CO modulates BK channels and the signaling pathways in HCFs using whole-cell mode patch-clamp recordings. CO-releasing molecules (CORMs; CORM-2 and CORM-3) significantly increased the amplitudes of BK currents (IBK). The CO-induced stimulating effects on IBK were blocked by pre-treatment with specific nitric oxide synthase (NOS) blockers (L-NG-monomethyl arginine citrate and L-NG-nitroarginine methyl ester). 8-bromo-cyclic GMP increased IBK. KT5823 (inhibits PKG) or ODQ (inhibits soluble guanylate cyclase) blocked the CO-stimulating effect on IBK. Moreover, 8-bromo-cyclic AMP also increased IBK, and pre-treatment with KT5720 (inhibits PKA) or SQ22536 (inhibits adenylate cyclase) blocked the CO effect. Pre-treatment with N-ethylmaleimide (a thiol-alkylating reagent) also blocked the CO effect on IBK, and DL-dithiothreitol (a reducing agent) reversed the CO effect. These data suggest that CO activates IBK through NO via the NOS and through the PKG, PKA, and S-nitrosylation pathways.

Coprisamides C and D (1 and 2) were isolated from a gut bacterium, Micromonospora sp. UTJ3, of the carrion beetle Silpha perforata. Based on the combined analysis of UV, MS, and NMR spectral data, the planar structures of 1 and 2 were elucidated to be unreported derivatives of coprisamides A and B, cyclic depsipeptides bearing a 2-alkenylcinnamic acid unit and the unusual amino acids β-methylaspartic acid and 2,3-diaminopropanoic acid. The absolute configuration of 1 was determined using the advanced Marfey's method, phenylglycine methyl ester derivatization, and J-based configuration analysis. The biosynthetic gene clusters for the coprisamides were investigated based on genomic data from coprisamide-producing strains Micromonospora sp. UTJ3 and Streptomyces sp. SNU533. Coprisamide C (1) was active against the Mycobacterium tuberculosis mc2 6230 strain.

Introduction of linker defects in a visible light responsive metal–organic framework (MOF) photocatalyst, MIL-125(Ti)–NH2, has been attempted to improve its reactivity. MIL-125(Ti)–NH2, composed of Ti-oxo cluster and 2-aminoterephthalic acid organic linker, was synthesized by a solvothermal method and then underwent photothermal treatments. XRD measurements and 1H NMR spectroscopy revealed that linker elimination from the MOF occurred by a simultaneous visible-light irradiation and mild heating at 313 K in water containing electron donor, while keeping its framework structure. The resultant defective MOF effectively promotes visible light-driven H2 evolution reaction from water containing electron donor without using any cocatalysts, and its activity is comparable to that of Pt cocatalysts-loaded crystalline MIL-125(Ti)–NH2. When pristine MIL-125(Ti)–NH2 without cocatalysts is used in the reaction, the reduction of Ti species in Ti-oxo clusters from Ti4+ to Ti3+ takes place instead of reducing protons to evolve H2; thereby, linker defect introduction caused by the photothermal treatment was concluded to play a role in creating effective reaction sites for proton reduction on Ti-oxo clusters.

Cross-linking technology has been considered as one of the effective strategies for improving the physicochemical stability of proton-exchange membranes (PEMs) for fuel cell applications. However, ...

Monohydroxyethyl terephthalate (MHET) hydrolase (MHETase) is an enzyme known to be involved in the final degradation step of poly(ethylene terephthalate) (PET) by hydrolyzing MHET into terephthalic...

Biodegradable polyesters, such as poly(butylene adipate-co-terephthalate) (PBAT), can trigger the hydrolysis of esters in a natural environment. However, biodegradability does not guarantee its eco-friendliness due to the concerns associated with terephthalic acid. Substitution by biomass-based counterparts no longer ensures “truly” eco-friendly biodegradable polyesters. In this study, we have used poly(butylene adipate-co-furanoate) (PBAF), which utilizes a biomass-derived substituent, furan-2,5-dicarboxylic acid (FDCA), and have proven that this is superior from the perspective of both mechanical performance and enzymatic degradation. Compared to its terephthalate counterpart, PBAF exhibits remarkable elasticity upon stretching: when released beyond 800% extension, PBAT almost malfunctioned, whereas PBAF exhibited instant elastic recovery. This results in PBAT and PBAF having a similar tensile strength in the range of 50–70 MPa at the ring fraction of 50 to 80 mol%. During the enzymatic degradation using lipase from Thermomyces lanuginosus, PBAF with a ring fraction of 50 mol% solely undergoes hydrolysis due to enzyme specificity. Ex situ spectroscopic analysis confirms that the participation of FDCA ester groups in the early stages of degradation triggered the successive hydrolytic reaction. Thus, understanding the structural characteristics of FDCA would open new opportunities in the field of sustainable plastic industries.

Anion conducting polymers (ACPs) are essential materials for alkaline electrochemical energy technology such as anion-exchange membrane fuel cells (AEMFCs) and water electrolysers (AEMWEs). The aforementioned polymers are promising alternatives for proton exchange membrane-based systems due to the possibility of using platinum group metal-free electrocatalysts. However, there are still no reliable ACPs possessing the desired performance and stability, which is a major challenge for developing alkaline energy systems. Herein, we highlight an anion-exchange membrane and ionomer based on quaternised poly-carbazole (QPC-TMA) with a rigid ether-free and curved backbone structure comprised of carbazole monomers. The developed ACP exhibits excellent ionic conductivity, as well as chemical and mechanical stability. Moreover, the AEMFC using QPC-TMA shows excellent performance (1.61 W cm−2) compared with the other best-performing AEMFCs. In addition, the AEMWE using QPC-TMA demonstrates outstanding stability and state-of-the-art performance (3.5 A cm−2 at 1.9 V), which is the first report of an AEMWE that outperforms the best-performing proton-exchange membrane water electrolysers.

Microwave-solvothermal synthesized MIL-101(Fe) was successfully loaded by silver halides (AgCl and AgBr) by simple precipitation method. The XRD, FESEM mapping, XPS and DRS measurements reveal the successful fabrication of composite photocatalyst. The results suggested that silver halides altered surface charge, surface area and pore size distribution of MIL-101(Fe). The 20%AgBr@MIL-101(Fe) composite has strong tendency to remove the cationic/anionic dyes (96% of rhodamine B, 100% of malachite green and 92% of methyl orange) from wastewater after 30 min of adsorption and 90 min under visible light irradiation. The composite photocatalyst revealed the photodegradation stability up to four cycles. The formation of mesopores improves the adsorption ability of the composites for large organic molecules, while loaded silver halides might inhibit the recombination of electron-hole pairs; those were responsible for enhancing the photocatalytic degradation of organic pollutants. ESR suggested O 2 · - , · OH were responsible for dye degradation in visible light by composite photocatalysts. The photocatalytic mechanism of the composite was also explained in this work.

C24H18N4O4, monoclinic, P21/c (no. 14), a = 16.5930(5) Å, b = 5.7298(2) Å, c = 20.8714(6) Å, β = 99.8620(10)°, V = 1955.02(11) Å3, Z = 4, R gt (F) = 0.0415, wR ref (F 2) = 0.1115, T = 193 K.

Iron-based metal-organic frameworks (MOFs) have been reported to display notable activity for photocatalytic water oxidation reaction (WOR). Previous reports published managed to grasp some of the important structural factors to develop activity, but no rigorous study has been accomplished toward the impact of the organic linkers on the WOR photoactivity. In this study, nine MOFs of the MIL-88B structure with different linkers were synthesized. The linkers were separated into two categories: those with electron-donating groups and those with electron-withdrawing substituents. MOFs fabricated from the latter linkers exhibited higher efficiency for WOR compared to the former, even though they demonstrated a lower visible light absorption ability. It was considered that the difference in reactivity originated from side reactions of the linkers toward reactive intermediates created during WOR, such as hydroxyl radical (OH•). Hydroxylation of terephthalic acid during WOR was confirmed by 1H NMR. Since the high...

We characterised the voltage-gated Ca2+ channels (VGCCs) in human cardiac fibroblasts (HCFs) and myofibroblasts (HCMFs) and investigated the effects of nitric oxide (NO) on apoptosis and on these channels. Western blotting and immunofluorescence analyses show that α-smooth muscle actin (a myofibroblast marker) was markedly expressed in passage (P) 12-15 but not in P4 HCF cells, whereas calponin (a fibroblast marker) was expressed only in P4 cells. CaV 1.2 (L-type) and CaV 3.3 (T-type) of VGCCs were highly expressed in P12-15 cells, but only weak CaV 2.3 (R-type) expression was identified in P4 cells using reverse transcription-polymerase chain reaction analysis. S-Nitroso-N-acetylpenicillamine (SNAP, an NO donor) decreased cell viability of HCMFs in a dose-dependent manner and induced apoptotic changes, and nifedipine (an L-type Ca2+ channel blocker) prevented apoptosis as shown with immunofluorescence staining and flow cytometry. Whole-cell mode patch-clamp recordings demonstrate the presence of L-type Ca2+ (IC a,L ) and T-type Ca2+ (IC a,T ) currents in HCMFs. SNAP inhibited IC a,L of HCMFs, but pre-treatment with ODQ (a guanylate cyclase inhibitor) or KT5823 (a PKG inhibitor) prevented it. Pre-treating cells with KT5720 (a PKA inhibitor) or SQ22536 (an adenylate cyclase inhibitor) blocked SNAP-induced inhibition of IC a,L . 8-Bromo-cyclic GMP or 8-bromo-cyclic AMP also inhibited IC a,L . However, pre-treatment with N-ethylmaleimide (a thiol-alkylating reagent) did not block the SNAP effect, nor did DL-dithiothreitol (a reducing agent) reverse it. These data suggest that high concentrations of NO injure HCMFs and inhibit IC a,L through the PKG and PKA signalling pathways but not through the S-nitrosylation pathway.

End-group cross-linked sulfonated poly(arylene ether sulfone) (SPAES) membranes were prepared using thiol capped SPAES (SH-SPAES) with different amounts of vinyl polysulfone (VPSf) as a polymeric cross-linker. The cross-linked membranes showed remarkably improved physicochemical stabilities compared to the corresponding linear SPAES membrane. Although the proton conductivity of the SPAES membrane composed of SPAES with the degree of sulfonation (DS) as 70 mol% could not be measured due to its low physical stability under the measurement condition, those of the cross-linked membranes were repeatedly evaluated due to the enhanced stability through the formation of cross-linked structures. The obtained proton conductivity values from cross-linked membranes are larger than those of the linear SPAES membrane which composed of SPAES with DS of 50 mol% having the ion exchange capacity (IEC) similar to that of the cross-linked membranes, especially at relative low humidity conditions. Furthermore, the fuel cell performance of the membrane electrode assembly (MEA) prepared with the cross-linked membrane, showing the optimized physicochemical stabilities and proton conductivity exhibited a maximum power density of 692 mW cm−2, which was larger than that with Nafion 212 (603 mW cm−2) at 80 °C under fully humidified H2/Air condition.

The title compound, C22H22N2O4S2, was synthesized by the reaction of 1,4,5,8-naphthalenetetracarboxylic dianhydride with 3-(methylsulfanyl)propylamine. The whole molecule is generated by an inversion operation of the asymmetric unit. This molecule has an anti form with the terminal methylthiopropyl groups above and below the aromatic diimide plane, where four intramolecular C—H...O and C—H...S hydrogen bonds are present and the O...H...S angle is 100.8°. DFT calculations revealed slight differences between the solid state and gas phase structures. In the crystal, C—H...O and C—H...S hydrogen bonds link the molecules into chains along the [2\overline20] direction. adjacent chains are interconnected by π–π interactions, forming a two-dimensional network parallel to the (001) plane. Each two-dimensional layer is further packed in an ABAB sequence along the c-axis direction. Hirshfeld surface analysis shows that van der Waals interactions make important contributions to the intermolecular contacts. The most important contacts found in the Hirshfeld surface analysis are H...H (44.2%), H...O/O...H (18.2%), H...C/C...H (14.4%), and H...S/S...H (10.2%).

Iron oxide (Fe2O3) aerogel powders were prepared by solvent exchange method using n-butanol without a supercritical fluid drying. The obtained aerogel powders have a porosity of 94%, a BET specific surface area of 421.1 m2/g, and an average pore size of 7.9 nm. The aerogel powders possessed a BET specific surface area of 51.8 m2/g even after calcination at 500 °C for 2 h despite the effect of pore shrinkage and particle coagulation. Initially, the Fe2O3 aerogel was amorphous, but some parts of it were changed to a crystalline structure after heat treatment.

Hydrothermal process was employed to synthesize the Yb3+/Tm3+, Yb3+/Ho3+ and Yb3+/Tm3+/Ho3+ doped BaMoO4 octahedron microcrystals (0.50–5.0 µm). The synthesized phosphors have scheelite tetragonal structure. The elemental mapping suggests the uniform distribution of elements in the samples. The oxidation state of samples were investigated by X-ray photoelectron spectroscopy (XPS) which indicates the existence of Ba2+, Mo6+, O, Yb3+, Tm3+ and Ho3+ in samples. The presence of rare earth ions was also verified by observation of specific absorption peaks in diffuse reflectance spectra (DRS). The tunable multicolor upconversion (UC) emissions were successfully obtained under 980 nm NIR excitation by precisely adjusting the concentration of rare earth ions. The as prepared sample exhibits blue, green and red emission as a result of energy transfer from the Yb3+ to Tm3+ and Ho3+ ions. The power dependent UC emission spectra show the two photonic processes. The energy transfer mechanism from Yb3+ to Tm3+ and Ho3+ was explained via an energy level analysis.

Molybdenum disulfide (MoS2) monolayer is one of the most promising materials for next-generation electronic/optoelectronic devices because of its prominent piezoelectric property that can modulate Schottky barrier height and control transport behaviors without applying any external gate bias. In this work, we systematically investigated temperature dependence of piezotronic effect of chemical vapor deposition grown MoS2 monolayer by measuring transport behaviors under strains from 0% to 0.3% with various sample temperatures ranging from 270 K to 320 K. It was found that piezoelectric effect in MoS2 monolayer significantly depends on sample temperature. Due to less screening effect of piezoelectric potential generated in MoS2 with a mechanical strain at low temperature, the piezotronic effect is significantly enhanced when the sample temperature is decreased from 320 K to 270 K, revealing that the piezoelectric effect becomes stronger at lower temperature.

Although, the use of hydrocarbon membranes is one of the ways to reduce the cost of polymer electrolyte membrane fuel cells, it cannot be practically adopted due to its low mechanical durability under a dynamic wet/dry operation. Here, we present an externally-reinforced hydrocarbon membrane achieved by a three dimensional interlocking interfacial layer which forms a strong interfacial bonding between the hydrocarbon membrane and the catalyst layers. Although a conventional hydrocarbon membrane is easily delaminated from gas diffusion electrodes, the use of the three dimensional interlocking interfacial layer, prepared with a polystyrene nanoparticle template method, enhances the interfacial adhesion by 207 times. The hydrocarbon membrane, tightly connected to the gas diffusion electrodes by the three dimensional interlocking interfacial layers, has a humidity cycling durability that is 1.9 times higher in the membrane electrode assembly level by restricting the dimensional change of the membrane. Furthermore, due to the proton conducting property of the three dimensional interlocking interfacial layer, the external reinforcement does not cause any power performance losses.

Ether-free poly(p-phenylene)-based anion exchange membrane materials with outstanding vanadium ion blocking properties are reported. The synthesized ionomers with a rigid backbone structure show small dimensional variations despite the high ion exchange capacities. Among the synthesized membranes, the QPPP-2 membrane with ion exchange capacity of 2.1 meq·g−1 exhibits high anion (OH−, SO42−, and Cl−) conductivity. The QPPP-2 membrane shows an extremely low diffusion coefficient (2.12 × 10−9 cm2 min−1) for VO2+, which is much lower than that of Nafion 115 (2.88 × 10−6 cm2 min−1), indicating the vanadium ion blocking property of QPPP-2. Moreover, the chemical and operational stabilities of the membranes are investigated via ex situ soaking tests in 0.1 M VO2+ solution and in situ operation tests for 100 cycles, respectively. The vanadium redox flow battery single cell assembled with the QPPP-2 membrane exhibits a coulombic efficiency of 99%, voltage efficiency of 87%, and energy efficiency of 86% during 100 cycles at 80 mA cm−2. The excellent chemical, morphological, and electrochemical properties of the QPPP-2 membrane make it suitable for use in vanadium redox flow battery.

A poly(ethylene)-reinforced anion exchange membrane based on cross-linked quaternary-aminated polystyrene and quaternary-aminated poly(phenylene oxide) was developed for reverse electrodialysis. Although reverse electrodialysis is a clean and renewable energy generation system, the low power output and high membrane cost are serious obstacles to its commercialization. Herein, to lower the membrane cost, inexpensive polystyrene and poly(phenylene oxide) were used as ionomer backbones. The ionomers were impregnated into a poly(ethylene) matrix supporter and were cross-linked in situ to enhance the mechanical and chemical properties. Pre-treatment of the porous PE matrix membrane with atmospheric plasma increased the compatibility between the ionomer and matrix membrane. The fabricated membranes showed outstanding physical, chemical, and electrochemical properties. The area resistance of the fabricated membranes (0.69–1.67 Ω cm2) was lower than that of AMV (2.58 Ω cm2). Moreover, the transport number of PErC(5)QPS-QPPO was comparable to that of AMV, despite the thinness (51 μm) of the former. The RED stack with the PErC(5)QPS-QPPO membrane provided an excellent maximum power density of 1.82 W m−2 at a flow rate of 100 mL min−1, which is 20.7% higher than that (1.50 W m−2) of the RED stack with the AMV membrane.

Water channel formation of non-perfluorinated proton exchange membranes (PEMs) under a low humidifying condition is a very important issue, due to weaker phase separation between hydrophilic and hydrophobic moieties than in the case of perfluorinated PEMs such as Nafion. In this study, we performed Molecular dynamics (MD) simulations of hydrated sulfonated polyimide (SPI) models, one of the representative non-perfluorinated PEMs, under different temperature and humidifying conditions by removing water molecules continuously, reflecting experimental conditions of actual low humidifying fuel cell. The water channel morphology of sulfonated polyimide (SPI) models had no apparent temperature dependence. The hydrated SPI models show weak water channel formation even in a fully hydrated condition (λ = 16.4), consistent with our previous study, and they do not display significant temperature dependence on the water molecule distribution. As the λ value decreases from 16.4 to 2 (i.e., low humidifying conditions), the water molecules in the hydrated SPI models are evenly reduced. In particular, when the λ value of the hydrated SPI model decreases from 8.5 to 6, the size of the water clusters is significantly narrowed and the clusters become segregated, and this is also confirmed by an X-ray scattering analysis. As a result, the proton conducting performance of hydrated SPI models shows similar behavior with the change in water channel morphologies, which will be very important to design a novel non-perfluorinated hydrocarbon PEM with high performance for practical fuel cell systems.

Binding energies of different nitrile solvents and their utilization for CuCN formation were investigated through quantum chemical calculations. A pulsed laser ablation in liquid (PLAL) method for CuCN synthesis was developed herein. Initially, the interaction between the pulsed laser and the Cu-target generated Cu-ions and electrons at the point of contact. The laser beam also exhibited sufficient energy to dissociate the bonds of the respective solvents. In the case of acetonitrile, the oxidized Cu-ions bonded with CN− to produce CuCN with a cube-like surface structure. Other nitrile solvents generated spherically-shaped Cu@graphitic carbon (Cu@GC) nanoparticles. Thus, the production of CuCN was favorable only in acetonitrile due to the availability of the cyano group immediately after the fragmentation of acetonitrile (CH3+ and CN−) under PLAL. Conversely, propionitrile and butyronitrile released large amounts of hydrocarbons, which deposited on Cu NPs surface to form GC layers. Following the encapsulation of Cu NPs with carbon shells, further interaction with the cyano group was not possible. Subsequently, theoretical study on the binding energies of nitrile solvents was confirmed by highly correlated basic sets of B3LYP and MP2 which results were consistent with the experimental outcomes. The findings obtained herein could be utilized for the development of novel metal–polymer materials.

The development of an eco-friendly and reliable process for the production of nanomaterials is essential to overcome the toxicity and exorbitant cost of conventional methods. As such, a facile and green synthesis method is introduced for the preparation of lignin mediated silver nanoparticles (L-Ag NPs). This is produced by reducing Ag precursors using lignin biopolymers which are formulated by pulsed laser irradiation and an ultrasonication process. Lignin operates as both a reducing and stabilizing agent. The various analytical techniques of ultraviolet–visible spectroscopy, transmission electron microscope and X-ray diffractometer studies were employed to verify the formation of non-aggregated spherical L-Ag NPs with an average size as small as 7–8 nm. The selective sensing capability of the synthesized L-Ag NPs was examined for the detection of hydrogen peroxide and mercury ions in an aqueous environment. Furthermore, the superior catalytic performance of L-Ag NPs was demonstrated by the rapid conversion of toxic 4-nitrophenol and nitrobenzene as targeted pollutants to the corresponding amino compounds. A plausible catalytic reduction mechanism for the removal of toxic nitro-organic pollutants over L-Ag NPs is proposed. This research coincides with existing studies and affirms that L-Ag NPs are an effective sensor that be applied as a catalytic material within environmental remediation and also alternative biomedical applications.

Comparative experiments were conducted to determine the effects of various solvents (i.e., deionized water, methanol, ethanol, 1-propanol, butanol, ethylene glycol, hexane, and acetonitrile) on the final compositions, morphologies, and catalytic activities of copper-based nanoparticles (NPs). The NPs were effectively synthesized by pulsed laser ablation (PLA) using a copper plate as the target. The obtained copper NPs were characterized utilizing various analytical techniques. It was established that the developed methodology allows for the production of NPs with different morphologies and compositions in a safe and simple manner. When laser ablation of a solid copper plate was performed in acetonitrile, the formation of copper(I) cyanide cubes was observed. On the other hand, in deionized water and methanol, spherical and rod-like particles of copper(I) and copper(II) oxide were detected, respectively. The catalytic activity of the prepared copper NPs in the reduction of aromatic nitro compounds, such as 4-nitrophenol and nitrobenzene, was also evaluated. A high k value was determined for the reduction over the copper(II) oxide NPs produced in methanol. Moreover, particles with graphitic carbon (GC) layers exhibited superior catalytic performance in the reduction of a hydrophobic substance, i.e., nitrobenzene, over the reduction of 4-nitrophenol. The enhanced catalytic activity of this catalyst may be due its unique surface morphology and the synergistic effects between the copper nanostructure and the GC layer. Lastly, a detailed reduction pathway mechanism for the catalytic reduction of 4-nitrophenol and nitrobenzene has been proposed.

Lydiamycin A (1) is a previously reported piperazic acid-bearing cyclic peptide from Streptomyces. The absolute configuration of lydiamycin A has not been fully determined despite the fact that multiple total syntheses have been reported. The absolute configuration of 1 was reinvestigated by the advanced Marfey's method, chemical derivatization, and quantum-mechanics-based computational analysis, eventually resulting in a structural revision and establishment of the complete configuration. Lydiamycin A displayed weak antituberculosis activity in vitro.

Bismuth vanadate (BiVO4) has been the subject of extensive investigation owing to its suitable bandgap (2.4 eV for monoclinic scheelite BiVO4 as compared with 3.2 eV of the well-known TiO2 photocatalyst) for efficient harvesting of solar energy for water oxidation and degradation of organic pollutants in wastewater. However, poor electrical conductivity and low charge separation efficiency of the photogenerated electrons and holes in BiVO4 limit its practical applications. In this chapter, we identify the potential issues and present a combined experimental and theoretical investigation for improving and understanding the photocatalytic activity of BiVO4 synthesized via microwave hydrothermal process. Various strategies of modifying the surface and bulk properties for improving the efficiency of BiVO4 such as metal and/or nonmetal doping, heterojunction formation, and upconversion-enhanced photocatalysis are systematically developed and discussed.

This study focuses on improving performance and durability of perfluorinated sulfonic acid (PFSA) membranes for polymer electrolyte membrane water electrolysis by controlling the membrane microstructure. To replace the highly gas permeable and expensive PFSA membranes, a membrane with low gas permeability and ohmic resistance is required for the high performing and safe water electrolyzers. Here, a thick PFSA membrane, Nafion 117 is biaxially stretched up to 6.4 times to reduce the membrane thickness, and increase the hydrophilic channels’ tortuosity. The thinned and planarly stretched Nafion shows better cell performance and durability at a constant current than the thick Nafion due to the reduced ohmic resistance and the enhanced interfacial stability between membrane and catalyst layer. With more tortuous hydrophilic pathways of the stretched Nafion, hydrogen permeability is reduced by a factor of 1.6, which is beneficial to prevent the membrane degradation and also to widen the operating current density range. The current density at 1.9 V increases from 1.5 to 3.2 A/cm2 after stretching, and the biaxially stretched membrane shows 4 times lower enhancement in ohmic and cathodic charge transfer resistance than the similarly thick Nafion after the constant current experiment, yielding 2.5 times lower degradation rate.

A multiblock copolymer containing a highly sulfonated poly(phenylene sulfide sulfone) (sPPSS) hydrophilic oligomer and a partially fluorinated perfluorocyclobutyl (PFCB)-containing hydrophobic oligomer was synthesized. The sharp contrast between the hydrophilic and hydrophobic moieties induced a well-developed phase separation, which was observed in the transmission electron microscopy (TEM) images within the polymer electrolyte membrane (PEM). The increased chain mobility from the flexible ether and PFCB groups afforded facile thermal annealing of the membrane. Thermal annealing induced polymer chain packing of the hydrophobic moieties, enhancing the hydrophilic/hydrophobic phase separation. The fabricated membranes exhibited higher proton conductivity compared with those of conventional hydrocarbon PEM possessing a random copolymer architecture, while their dimensional swelling was suppressed. Additionally, under low humidification (a relative humidity (RH) of 50%), the sulfonated–fluorinated membrane achieved a high proton conductivity of up to 41.9 mScm−1. A high adhesion strength of 32.7 mNcm−1 was also observed, indicating strong interfacial compatibility in the membrane electrode assembly (MEA) due to its structural affinity for the contacting perfluorosulfonated binder. The enhanced hydrophilic/hydrophobic phase separations facilitated fuel cell performances of 1.13 and 0.61 Acm−2 at 0.6 V and 65 °C under 100% and 50% RH conditions, respectively, in addition to achieving stable chemical and physical durabilities.

Abundant yet undeveloped, cellulose and various derivatives of cellulose are materials that we see and touch every day. Here, we report a novel polymer proton conducting electrolyte synthesized by chemical modification of hydroxypropyl cellulose, which opens a new possibility of utilizing a renowned environmental friendly material for environmentally friendly applications. The modified cellulose by attaching sulfonic acid functional groups exhibits proton conductivity of 172 mS/cm at room temperature under 100% relative humidity with negligible electron or hole leakage through the membrane. By hybridizing the modified cellulose with aluminum fumarate metal-organic-framework (A520), dehydration of the cellulose based electrolyte membrane is significantly moderated to enhance low humidity conductivity by more than an order of magnitude. The A520 hybridized sulfonated cellulose is utilized as the electrolyte for all-solid-state supercapacitor, which demonstrated specific capacitance as high as 135.14 F/g at 75% relative humidity with stable performance even at low humidity.

We develop a novel approach to improve the robustness of the interface between the hydrocarbon (HC) membrane and the perfluorosulfonic acid (PFSA) ionomer-based catalyst layer (CL) in membrane electrode assemblies (MEAs). This approach involves the creation of a gradient-composition interfacial bonding layer, in which the HC and PFSA contents are gradually varied along the thickness direction. The layer is fabricated using a simple spray-coating method, in which HC and PFSA ionomer mixtures with different compositions are sprayed stepwise onto both sides of the HC membrane surface. The interfacial structure developed in this process minimizes the chemical incompatibility between the HC and PFSA polymers. Owing to the tightly bound sublayers resulting from the intertwined HC and PFSA microdomains, the gradient-composition bonding layer provides a significantly improved interfacial adhesion strength (14 times higher than that of the pristine membrane without bonding layer) between the HC membrane and the PFSA-based CL. Finally, the fabricated MEA exhibits a >433% higher durability in humidity cycling tests compared with the pristine MEA without interfacial bonding layer, together with a better retention of its initial performance.

In this study, poly(ethylene 2,5-furan dicarboxylate) (PEF) was synthesized from biomass-based dimethyl furan-2,5-dicarboxylate using different-sized zeolites, with substituted ions such as Li and K, as efficient green catalysts for in situ polymerization. The Z5Ali catalyst yielded the PEF biopolyester with the highest weight-average molecular weight among all the samples: 53,800 g/mol. From their TGA curves, it was confirmed that the PEF sample with ZA5Li as the catalyst showed an increased thermal stability compared to homo-PEF. Generally, homo-PEF exhibited a very low melt-crystallization rate with low enthalpy. However, all the PEF samples using zeolite as the catalyst formed endotherms I and II. This result was attributed to the fact that zeolite affects the melt and recrystallization of imperfect crystals due to physical hindrance.

Herein, we report the effects of applied voltage on the electrochromic (EC) stability of poly(3-hexylthiophene) (P3HT) films during EC reactions. The transmittance difference and cycling stability of these films were monitored to optimize the oxidation voltage, and their chemical compositions were analyzed by X-ray photoelectron spectroscopy after long-term electrochemical cycling. High oxidation voltages increased the color contrast of P3HT films but decreased their cycling stability due to facilitating chemical degradation. Furthermore, at an optimized oxidation voltage, the retention time during potential pulsing was adjusted utilizing the optical memory of P3HT, revealing that the decreased voltage application time reduced power consumption by 9.6% and enhanced EC stability without loss of color contrast.

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.

The title compound, (systematic name:N,N′-dibenzyl-3,3′-dimethoxy-1,1′-biphenyl-4,4′-diamine), C28H28N2O2, was synthesized by the reduction of a Schiff base preparedviaa condensation reaction betweeno-dianisidine and benzaldehyde under acidic conditions. The molecule lies on a crystallographic inversion centre so that the asymmetric unit contains one half-molecule. The biphenyl moiety compound is essentially planar. Two intramolecular N—H...O hydrogen bonds occur. The dihedral angle between the terminal phenyl and phenylene rings of a benzidine unit is 48.68 (6)°. The methylene C atom of the benzyl group is disordered over two sets of sites, with occupancy ratio 0.779 (18):0.221 (18). In the crystal, molecules are connected by hydrogen bonding betweeno-dianisidine O atoms and H atoms of the terminal benzyl groups, forming a one-dimensional ladder-like structure. In the data from DFT calculations, the central biphenyl showed a twisted conformation.

Cobalt-incorporated zeolitic imidazolate framework ZIF-8 was synthesized by a simple one-pot synthesis method at room temperature. Powder X-ray diffraction patterns and energy dispersive X-ray spectrum confirmed the formation of the bimetallic Co/Zn-ZIF structure. UV-Vis diffuse reflectance spectra revealed that the bimetallic ZIF had a lower HOMO-LUMO gap compared with ZIF-8 due to the charge transfer process from organic ligands to cobalt centers. A hydrolytic stability test showed that Co/Zn-ZIF is very robust in aqueous solution - the most important criterion for any material to be applied in photodegradation. The photocatalytic efficiency of the synthesized samples was investigated over the Indigo Carmine (IC) dye degradation under solar simulated irradiation. Cobalt incorporated ZIF-8 exhibited high efficiency over a wide range of pH and initial concentration. The degradation followed through three distinct stages: a slow initial stage, followed by an accelerated stage and completed with a decelerated stage. Moreover, the photocatalytic performance of the synthesized samples was highly improved in alkaline environment rather than in acidic or neutral environments, which may have been because in high pH medium, the increased concentration of hydroxyl ion facilitated the formation of hydroxyl radicals, a reactive species responsible for the breaking of the Indigo Carmine structure. Thus, Co/Zn-ZIF is a promising and green material for solving the environmental pollution caused by textile industries.

We prepared in situ gelling alginate (ALG)/hyaluronic acid (HA) hydrogels with a controllable gelation rate using CaSO4 as a crosslinking agent and Na2HPO4 as a crosslinking retardation agent. The ALG/HA hydrogels provided sustained release of bone morphogenetic protein-2 (BMP-2) immobilized in the hydrogels over 5 weeks. The BMP-2-immobilized ALG/HA hydrogels with different ALG/HA ratios were investigated for their in vitro osteogenic differentiation behavior of human bone marrow stem cells (hBMSCs) and in vivo bone regeneration behavior using an animal model (mandibular defect model of miniature pigs). Our findings from cell culture and animal study demonstrated that the osteogenic differentiation of hBMSCs was improved with increasing HA composition in the hydrogel. The hBMSCs/BMP-2-immobilized ALG/HA hydrogel allowed greatly enhanced osteogenic differentiation of hBMSCs (in vitro) and bone regeneration (in vivo) compared with the ALG/HA hydrogel itself and single hBMSCs- or BMP-2-immobilized hydrogel groups.

A series of sulfonated poly(ether sulfone) copolymers (SPES-Xs) with varying degrees of sulfonation were prepared and investigated as ion-exchange membranes for vanadium redox flow battery (VRFB) applications. Sulfonated poly(thioether ether sulfone) copolymers (SPTES-Xs) were initially synthesized via polycondensation, and the SPES-Xs were then obtained by oxidation of the corresponding SPTES-Xs. The SPES-X membranes showed reduced vanadium-ion permeability, low area resistance, and, thereby, much superior selectivity compared with the parent SPTES-X membranes and a Nafion115 membrane. In single-cell VRFB performance tests, a SPES-50 membrane with an ion-exchange capacity of 1.80 meq/g exhibited a higher coulombic efficiency (>99%) and energy efficiency (76–89%) than the Nafion115 membrane over a wide range of current densities from 40 to 100 mA/cm2 and a significantly larger capacity retention (>62%) during 200 charge-discharge cycles. The SPES-X materials, in which every benzene ring is deactivated by the presence of electron-withdrawing sulfone linkages, showed much better chemical stability during ex situ and in situ tests than the SPTES-X materials, which contain an electron-donating thioether linkage in their repeat unit.

Sustainable biobased terpolyester based on heterocyclic dimethyl furan-2,5-dicarboxylate and isosorbide in combination with ethylene glycol and 1,4-cyclohexanedimethylene (PEICF) were successfully synthesized by two-step melt polymerization method and characterized. A series of PEICF terpolyester exhibited excellent heat resistive properties, with glass transition temperatures of 81–119 °C, and high molecular weights (Mw = 50,800 g mol−1). When esterification was carried out at fixed a COOH:OH molar ratio of 1:2, 1,4-cyclohexanedimethanol (CHDM) showed increased reactivity compared to isosorbide (ISB) and ethylene glycol (EG) monomers. As a result, EG was most likely to be placed at the end of the oligomer chains, which accelerated the transesterification process and drastically increased chain growth via chain scission at the carbonyl carbon adjacent to the ethylene unit due to steric hindrance. The zero shear viscosities of the PEICF terpolyester were much higher than that of the copolyester and increased with increasing ISB content. This study proposed a method for improving the low reactivity of dimethyl furan-2,5-dicarboxylate, which shows suppressed furan ring flipping, with sterically hindered ISB by using highly reactive CHDM at atmospheric pressure. These results signify the importance of controlling the synthetic conditions, as they affect the composition of the polymer backbone due to the different reactivities, volatilities, and steric hindrances of the monomers.

Conventionally, highly proton conductive perfluorosulfonic acid (PFSA) ionomers are used for an electrolyte membrane in a polymer electrolyte membrane water electrolyzer. As alternatives to the expensive and highly hydrogen permeable PFSA membranes, hydrocarbon-based sulfonated poly(arylene ether sulfone) proton conducting polymers (BPSH) are synthesized by varying their ion exchange capacity (IEC) from 1.2 to 2.0 meq/g, and the way to employ ion conducting units into polymers (random versus block). BPSH membranes show much lower hydrogen permeability (20 − 45 barrer) than that of PFSA membranes (~115 barrer for Nafion) at 80 °C and 100%RH. Random BPSH membranes show slightly higher selectivity of proton to hydrogen than the membranes from multi-block BPSH copolymers at a similar IEC may due to the enhanced hydrogen barrier property by less-developed hydrophilic phase. The best performing random BPSH with the IEC ~ 1.9 meq/g shows better performance (5.3 A/cm2) than the similarly thick (~50 μm) Nafion 212 (4.8 A/cm2) at 1.9 V, but the higher degradation rate (951 μV/h) than Nafion 212 (613 μV/h) at an accelerated stress test with the 360 consecutive alternating current densities of 3 and 0.02 A/cm2, simulating on and off a water electrolyzer.

The structure of the title copper(I) coordination polymer is reported. One CuI atom is surrounded by three μ3-iodide anions and one S atom, while the other is coordinated by three μ3-iodide ions an O atom. In the crystal, there are inter­molecular C—H⋯I hydrogen bonds and C—H⋯π inter­actions between ligands. The packing generates a two-dimensional brick-wall structure., The reaction of copper(I) iodide with 1-[2-(cyclo­hexyl­sulfan­yl)eth­yl]pyridin-2(1H)-one (L, C13H19NOS) in aceto­nitrile/di­chloro­methane results in a crystalline coordination polymer, namely poly[bis­{μ2-1-[2-(cyclo­hexyl­sulfan­yl)eth­yl]pyridin-2(1H)-one}tetra-μ3-iodido­tetra­copper(I)], [Cu4I4 L 2]n. The asymmetric unit comprises two ligand mol­ecules, four copper(I) ions and four iodide ions. Inter­estingly, the O atoms are bound to the soft copper(I) ions. The stair-step clusters of Cu and I atoms in the asymmetric unit are linked repeatedly, giving rise to infinite chains along [100]. Neighbouring infinite chains are linked through the L mol­ecules, forming a two-dimensional brick-wall structure. These two-dimensional networks are stacked alternately along [001]. Additionally, there are inter­molecular C—H⋯I hydrogen bonds and C—H⋯π inter­actions between the ligands.

A series of polysulfone-based crosslinked anion exchange membranes (AEMs) with primary diamine-based crosslinkers has been prepared via simple a crosslinking process as low-cost and durable membranes for vanadium redox flow batteries (VRFBs). Chloromethylated polysulfone is used as a precursor polymer for crosslinked AEMs (CAPSU-x) with different degrees of crosslinking. Among the developed AEMs, CAPSU-2.5 shows outstanding dimensional stability and anion (Cl−, SO42−, and OH−) conductivity. Moreover, CAPSU-2.5 exhibits much lower vanadium ion permeability (2.72 × 10−8 cm2 min−1) than Nafion 115 (2.88 × 10−6 cm2 min−1), which results in an excellent coulombic efficiency of 100%. The chemical and operational stabilities of the membranes have been investigated via ex situ soaking tests in 0.1 M VO2+ solution and in situ operation tests for 100 cycles, respectively. The excellent chemical, physical, and electrochemical properties of the CAPSU-2.5 membrane make it suitable for use in VRFBs.

For graphene-based composites, the dynamics of polymers confined between graphene sheets are a key parameter governing the overall mechanical properties of bulk materials. Here, we used neutron reflectivity (NR) to measure the diffusion dynamics of polymer melts confined between graphene oxide (GO) surfaces. From the NR results, we found that the diffusion coefficients of poly(methyl methacrylate) (PMMA) between the GO sheets were dramatically reduced by more than 1 order of magnitude when the film thickness was less than ∼3 times the gyration radius of the bulk polymer (Rg), whereas the diffusion of the polystyrene (PS) films sandwiched between GO sheets was only three times slower as the PS thickness decreased from ∼8 Rg to 1 Rg. This difference was due to the fact that the polymer-GO interaction significantly influences the dynamics of confined polymer melts.

Co-doped BiVO4, a visible-light-responsive photocatalytic semiconductor, was synthesized using a microwave hydrothermal method. The doped sample exhibited much higher photocatalytic activity for malachite green degradation under visible light irradiation than undoped BiVO4. Similarly, improved inactivation efficiency toward Escherichia coli and Chlamydomonas pulsatilla (green tide) were observed with Co-doped BiVO4. The degradation of malachite green by Co-doped BiVO4 reaches 99% within 90 min irradiation to visible light. Similarly, the inactivation of Escherichia coli reaches 81.3% in 5 h and Chlamydomonas pulsatilla reaches 65.6% in 1 h irradiation to visible light. The enhanced photoactivity is believed to be due to the increment of the visible light absorption range by narrowing the band gap energy. In addition, the highly exposed reactive (010) facets can efficiently capture the photoinduced electrons, promote charge separation, and reduce recombination probability. Thus, these findings provide mechanistic insight into the effectiveness of Co-doped BiVO4 semiconductors for the treatment of wastewater that contains industrial effluents and microorganisms.

Organic electrochromic (EC) materials are generally known to be electrochemically unstable during the ion intercalation/deintercalation process. One effective method to stabilize them is incorporating graphene derivatives in the polymer matrix, thereby creating strong interaction between graphene derivatives and polymer. However, previous studies are limited to specific polymers and bulk-blended systems, such as mixing the polymer with graphene derivatives. In this study, we developed a polymer-graphene derivative complex with the chemical assistance of a surfactant (octadecylamine, ODA). Graphene oxide (GO) was introduced as a protective layer on the electrochromic poly(3-hexyl thiophene) (P3HT) films by the Langmuir-Schaefer method. The deposition of the GO-ODA protective layer with high coverage was confirmed by atomic force microscopy and high-resolution X-ray reflectivity. The strong interactions between GO-ODA and P3HT were examined with UV-vis spectrophotometry and X-ray photoelectron spectroscopy. Electrochemical and electrochromic investigations revealed that the GO-ODA layer greatly improved the long-term cyclability of the P3HT film. These findings imply that the GO-ODA complex can significantly stabilize the EC cycling, due to its strong interaction with the P3HT film.

The title compound, C30H44N2O4[systematic name: 2,6-didecylpyrrolo[3,4-f]isoindole-1,3,5,7(2H,6H)-tetraone], consists of a central pyromellitic diimide moiety with terminal decyl groups at the N-atom positions. The centre of the molecule lies on a crystallographic inversion centre so the asymmetric unit contains one half-molecule. The molecule exhibits a rod-shaped conformation, like other similar compounds of this type, the distance between the ends of terminal decyl groups being 32.45 Å. The packing is dominated by a lamellar arrangement of the molecules, which is reinforced by C—H...O hydrogen bonds and C—O...π interactions, forming a classic herringbone structure. The molecular structure is consistent with the theoretical calculations performed by density functional theory (DFT).

Urotensin II (UII) is a mitogenic and hypertrophic agent that can induce the proliferation of vascular cells. UII inhibition has been considered as beneficial strategy for atherosclerosis and restenosis. However, currently there is no therapeutics clinically available for atherosclerosis or restenosis. In this study, we evaluated the effects of a newly synthesized UII receptor (UT) antagonist, KR- 36996, on the proliferation of SMCs in vitro and neointima formation in vivo in comparison with GSK-1440115, a known potent UT antagonist. In primary human aortic SMCs (HASMCs), UII (50 nM) induced proliferation was significantly inhibited by KR-36996 at 1, 10, and 100 nM which showed greater potency (IC₅₀: 3.5 nM) than GSK-1440115 (IC₅₀: 82.3 nM). UII-induced proliferation of HASMC cells was inhibited by U0126, an ERK1/2 inhibitor, but not by SP600125 (inhibitor of JNK) or SB202190 (inhibitor of p38 MAPK). UII increased the phosphorylation level of ERK1/2. Such increase was significantly inhibited by KR-36996. UII-induced proliferation was also inhibited by trolox, a scavenger for reactive oxygen species (ROS). UII-induced ROS generation was also decreased by KR-36996 treatment. In a carotid artery ligation mouse model, intimal thickening was dramatically suppressed by oral treatment with KR-36996 (30 mg/kg) which showed better efficacy than GSK-1440115. These results suggest that KR-36996 is a better candidate than GSK-1440115 in preventing vascular proliferation in the pathogenesis of atherosclerosis and restenosis.

ObjectivesWe analyzed the clinical follow-up results of 88 lupus nephritis patients to find prognostic factors for the development of chronic kidney disease in ethnically homogeneous Korean patients with biopsy-proven lupus nephritis.MethodsSociodemographic, clinical, laboratory, and treatment-related data at the time of kidney biopsy and during follow-up were obtained. Renal biopsy specimens were reclassified according to the International Society of Pathology/Renal Pathology Society classification, separately, by two renal pathologists blinded to the previous classification. Univariate and multivariate analyses were performed using the Cox proportional hazard regression model to identify independent risk factors for chronic kidney disease in lupus nephritis patients.ResultsEighteen of 88 patients (20.5%) developed chronic kidney disease during a mean follow-up of 47.6 months (range: 12–96 months). Patients who developed chronic kidney disease were older at onset of lupus nephritis, had less education, and were more likely to have hypertension; they had lower serum albumin levels, lower platelet levels, higher serum creatinine levels, lower estimated glomerular filtration rate, higher chronicity index, and lower frequency of anti-ribosomal P antibodies, and they were less likely to be in complete remission in the first year. In stepwise multivariable analyses, hypertension, lower glomerular filtration rate, and failure to achieve complete remission in the first year of treatment were significant predictors of the development of chronic kidney disease in lupus nephritis patients.ConclusionsThese findings suggest that patients with hypertension and decreased kidney function at the onset of lupus nephritis and showing a poor response to immunosuppressive drugs in the first year should be monitored carefully and managed aggressively to avoid deterioration of kidney function.