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In this work, electrospun PBI separators with a highly porous structure and nanofiber diameter of about 90-150 nm are prepared using a multi-nozzle under controlled conditions for lithium metal batteries. Cross-linking with α, α-dibromo-p-xylene and surface treatment using 4-(chloromethyl) benzoic acid successfully improve the electrochemical as well as mechanical properties of the separators. The resulting separator is endowed with high thermal stability and excellent wettability (1080 to 1150%) with commercial liquid electrolyte than PE and PP (Celgard 2400) separators. Besides, attractive cycling stability and rate capability in LiFePO

Considering the critical energy challenges and the generation of zero-emission anion exchange membrane (AEM) sources, chitosan-based anion exchange membranes have garnered considerable interest in fuel cell applications owing to their various advantages, including their eco-friendly nature, flexibility for structural modification, and improved mechanical, thermal, and chemical stability. The present mini-review highlights the advancements of chitosan-based biodegradable anion exchange membranes for fuel cell applications published between 2015 and 2022. Key points from the rigorous literature evaluation are: grafting with various counterions in addition to crosslinking contributed good conductivity and chemical as well as mechanical stability to the membranes; use of the interpenetrating network as well as layered structures, blending, and modified nanomaterials facilitated a significant reduction in membrane swelling and long-term alkaline stability. The study gives insightful guidance to the industry about replacing Nafion with a low-cost, environmentally friendly membrane source. It is suggested that more attention be given to exploring chitosan-based anion exchange membranes in consideration of effective strategies that focus on durability, as well as optimization of the operational conditions of fuel cells for large-scale applications.

To mitigate the dependence on fossil fuels and the associated global warming issues, numerous studies have focused on the development of eco-friendly energy conversion devices such as polymer electrolyte membrane fuel cells (PEMFCs) that directly convert chemical energy into electrical energy. As one of the key components in PEMFCs, polymer electrolyte membranes (PEMs) should have high proton conductivity and outstanding physicochemical stability during operation. Although the perfluorinated sulfonic acid (PFSA)-based PEMs and some of the hydrocarbon-based PEMs composed of rationally designed polymer structures are found to meet these criteria, there is an ongoing and pressing need to improve and fine-tune these further, to be useful in practical PEMFC operation. Incorporation of organic/inorganic fillers into the polymer matrix is one of the methods shown to be effective for controlling target PEM properties including thermal stability, mechanical properties, and physical stability, as well as proton conductivity. Functionalization of organic/inorganic fillers is critical to optimize the filler efficiency and dispersion, thus resulting in significant improvements to PEM properties. This review focused on the structural engineering of functionalized carbon and silica-based fillers and comparisons of the resulting PEM properties. Newly constructed composite membranes were compared to composite membrane containing non-functionalized fillers or pure polymer matrix membrane without fillers.

In this study, free-standing PIL/IL composite membranes of 1-bromohexyl-1 methylpiperidinium bromide (Br-6-MPRD) grafted poly(2,6 dimethyl 1,4 phenylene oxide) (ILPPO) incorporated with different amounts of free Br-6-MPRD (0, 2, 5 and 10 wt%) were prepared and the effect of free ionic liquid on CO2, N2 and O2 transport properties were reported. The structure of piperidinium based polyionic liquid (PIL) synthesised was confirmed using nuclear magnetic resonance (NMR) and Fourier transform infrared (FTIR) spectral techniques. Gas permeation results at 1 bar pressure and 25 °C revealed the best CO2 permeability and CO2/N2 as well as CO2/O2 permselectivities of the membrane stretch to 907.20 Barrer (higher than Pebax® 1657), 12.94 and 14.90 respectively for ILPPO/Br-6-MPRD-2 which come within reach of the 2008 Robeson limit. Apart from most of the published works, ILPPO/Br-6-MPRD-2 membrane revealed an anti-trade-off permeability-selectivity performances which is most required and a great challenge for CO2 separation and capture applications.

Anion exchange membranes (AEMs) with good alkaline stability and ion conductivity are fabricated by incorporating quaternary ammonium-modified silica into quaternary ammonium-functionalized poly(2,6-dimethyl-1,4-phenylene oxide) (QPPO). Quaternary ammonium with a long alkyl chain is chemically grafted to the silica in situ during synthesis. Glycidyltrimethylammoniumchloride functionalization on silica (QSiO2) is characterized by Fourier transform infrared and transmission electron microscopic techniques. The QPPO/QSiO2 membrane having an ion exchange capacity of 3.21 meq·g–1 exhibits the maximum hydration number (λ = 11.15) and highest hydroxide ion conductivity of 45.08 × 10–2 S cm–1 at 80 °C. In addition to the high ion conductivity, AEMs also exhibit good alkaline stability, and the conductivity retention of the QPPO/QSiO2-3 membrane after 1200 h of exposure in 1 M potassium hydroxide at room temperature is about 91% ascribed to the steric hindrance offered by the grafted long glycidyl trimethylammonium chain in QSiO2. The application of the QPPO/QSiO2-3 membrane to an alkaline fuel cell can yield a peak power density of 142 mW cm–2 at a current density of 323 mA cm–2 and 0.44 V, which is higher than those of commercially available FAA-3-50 Fumatech AEM (OCV: 0.91 V; maximum power density: 114 mW cm–2 at current density: 266 mA cm–2 and 0.43 V). These membranes provide valuable insights on future directions for advanced AEM development for fuel cells.

In fuel cell and electrolysis systems, hydrogen crossover is a phenomenon where hydrogen molecules (H2) permeate through a membrane, lowering the overall process efficiency and generating a potential safety risk. Many works have been reported to mitigate this undesired phenomenon, but it is yet difficult to accurately measure the rate of hydrogen crossover, particularly when the membrane is fully wetted in water. In this work, we investigated the pressure decay method as a simple, convenient, and low-cost method to characterize hydrogen crossover through wetted membranes for water electrolysis systems. Three different ion exchange membranes were analyzed: Nafion 212, Nafion 115, and in-house sulfonated poly(arylene ether sulfone). We rigorously confirmed our method and data by comparing it to the ANSI dataset with the current state-of-the-art equations of state (EOS) to account for the nonideality of high pressure hydrogen systems. The error from the gas non-ideality was less than 0.03%. As expected, the rate of hydrogen crossover showed high dependency on the temperature; more importantly, hydrogen crossover increased significantly when the membrane was fully soaked in water. For dry membranes, the proposed pressure decay method corroborated well with the literature data measured using other known methods. Moreover, for wetted membranes, the obtained data showed high similarity compared to the GC method which is currently the most reliable method in the literature. We attempted to predict the hydrogen permeability of wetted membranes using the solution diffusion model. The model based on the given thermodynamic parameters overestimated the hydrogen permeability, which can be used to estimate the ion channel tortuosity.

In this study, we investigated facile “dragging mode” electrohydrodynamic (EHD) jet printing of a polymer-wrapped semiconducting single-walled carbon nanotube (s-SWCNT) ink, for fabrication of NO gas-sensing field-effect transistors (FETs). The “dragging mode” provides a favorable environment for reliable printing and interconnection between the s-SWCNTs. Printing parameters such as supply voltages, printing speeds, and the number of prints were manipulated to find an optimal printing condition and obtain high-performance FETs. Under optimal conditions, the polymer-wrapped s-SWCNT-based FETs exhibited an average field-effect mobility of 2.939 cm2 (V−1 s−1), a threshold voltage of 2.21 V, an on/off ratio of ∼103, and a subthreshold swing of 0.968 V dec−1. Additionally, we demonstrated the application of FETs as NO sensors with high sensitivity and selectivity. The FET-type NO gas sensor exhibits a dynamic sensing range of 500 ppb–30 ppm and clear selectivity among various analyte gases including ethanol, ammonia, and acetone. Therefore, the “dragging mode” EHD jet printing introduced in this study simplifies patterning processes and is a potential reproducible method for the fabrication of next-generation gas sensors.

The process of crosslinking is widely employed to increase the physicochemical stability of anion exchange membranes and, in some cases, improve ion conductivity. For a general case in which a polymer is crosslinked by a crosslinking agent, the physicochemical properties of the polymer can be greatly altered, depending on the type of crosslinking agent. In this study, we induced crosslinking without a crosslinking agent to intentionally maximise various physical properties (i.e., mechanical properties, swelling ratios, and so forth) of two commercially-available polymers. A triazole was incorporated into the conducting group to maximise the ion conductivity, especially under room humidity (RH) conditions. The crosslinked PPO-SEBS membranes prepared through this approach were not only capable of forming very thin membranes (10 μm thickness) with excellent physical properties (34.3 MPa of tensile strength and 91.6% of elongation at break) but also exhibited high hydroxide ion conductivity under 95% RH, and conductivity plays an important role in achieving good fuel cell performance. When the membrane electrode assembly (MEA), as fabricated utilising a crosslinked PPO-SEBS membrane and a platinum on carbon (Pt/C) catalyst on each electrode, was operated in conditions with a H2/O2 gas flow and a 60 °C temperature, a stable fuel cell performance was obtained for a long period of time (300 hours) at a maximum power density of 405 mW cm−2. This result surpasses the performance of commercialized AEMs and is comparable with the performance levels of cutting-edge AEMs when operated under similar conditions.

Printed electronics will be essential in the implementation of next-generation electronic devices, because printing facilitates fabrication of devices on various rigid, thin, or flexible substrates. Inkjet printing enables precise placement of fine droplets of different functional materials; moreover, it is inexpensive and adaptable for mass production. Electrohydrodynamic (EHD) jet printing, a type of inkjet technology, can generate very fine ink droplets by applying an electric field between the substrate and the nozzle; therefore, it is a promising candidate for high-resolution direct printing, which is essential in the manufacturing of various devices. More significantly, the characteristics of EHD jet printing can be conveniently adjusted by modulating the electric field strength, and various functional inks can be used in this process. This paper is a comprehensive review of recent progress in EHD jet printing technology to fabricate various electronic devices and circuits. Applications of various functional inks (electrode, semiconductor, dielectric materials) for each electronic component are also described.

In this study, PEEKs with different contents of imidazolium group (DI-PEEK) were synthesized by facile condensation polymerization using bisphenol A, 2,2′-di(2-ethyl-methylimidazole-methylene)-4,4′-dihydroxydiphenylether and difluorobenzophenone. Highly flexible and transparent DI-PEEK membranes showing anion exchange behavior could be prepared by the DI-PEEK solution using DMAc as a solvent. The DI-PEEK membrane with optimized content of imidazolium group (30 mol%) showed the highest ion conductivity (78 mS/cm at 80 ℃) without deterioration of thermal and mechanical stability among the samples. A membrane electrode assembly using the DI-PEEK membrane with optimized content of imidazolium group revealed comparable cell performance (98 mW/cm2 at 0.43 V) to that using a commercialized anion exchane membrane (114 mW/cm2 at 0.43 V) under operating conditions of 60 ℃ and 100% RH.

The prickly pear cactus (Opuntia), native to Mexico, has grown in popularity and is locally grown and adapted on Jeju Island. The fruits of this cactus species are in particular widely employed as raw materials, which are then processed into various food and medicinal items, including chocolates and vitamins, for purposes of human consumption. Because this crop has been dubbed one of Jeju’s iconic agricultural crops, research studies elucidating the prickly pear cactus’ medicinal properties, including antioxidant activity, of this particular plant and related cultivated species have demonstrated high value to the scientific community. Currently, consumers do not purchase products f or c onsumption a lone, but in a ddition f or t heir added health benef its. The present study in particular honed in on two species of prickly pear cactus that are cultivated on Jeju Island which include: ‘Baeknyeoncho’ (Opuntia ficus-indica) and ‘Cheonnyeoncho’ (Opuntia humifusa). From these species, s pecif ci p lant p arts i ncluding t he f lower, mature and y oung stems, roots, a nd f ruit w ere subjected to further antioxidant analysis, which included the determination of polyphenol, flavonoid, DPPH radical, ABTS radical, and anthocyanin levels. These particular antioxidants were determined during two seasons, over the course of the summer and winter. Results revealed that the antioxidant activity for both species was more active during the summer season. Antioxidant levels occurred at the highest rates within t he flowers o f the c actus plants. However, of significant note was that the cactus stem, in both mature and young plants, possessed higher antioxidant activity compared to those of the fruit that is currently employed for commercial purposes.

We chemically modify a commercially available elastomeric triblock copolymer, poly(styrene-b-ethylene-co-butylene-b-styrene) SEBS, to produce quaternary ammonium-functionalized hexyl bis(quaternary ammonium)-mediated partially-crosslinked SEBSs with different grafting degree of the conducting head groups as highly conductive and stable anion exchange membranes (AEMs). In an attempt to achieve a high ion exchange capacity and hence conductivity of the corresponding membranes without causing ‘gelation’, which these types of SEBS polymers typically experience, we use a SEBS with a high content (57%) of styrene, and graft the quaternary ammonium (QA) as both a crosslinker and the conducting head group on the side chain of the SEBS. The partial crosslinking approach, in combination with introducing these QA-conducting head groups as the side chain of the SEBS, helps to form larger ion clusters, and also to form a nano-phase morphology with long-range connecting channels. This induced the highest ion conductivity, 174.8 mS cm−1 at 80 °C, reported to date among these types of SEBS series. In addition, we obtain excellent cell performance with a current density of 450 mA cm−2 at 0.6 V and a peak power density of 315 mW cm−2 at 95% RH and 60 °C using the corresponding AEM.

Due to increased environmental pressures, significant research has focused on finding suitable biodegradable plastics to replace ubiquitous petrochemical-derived polymers. Polyhydroxyalkanoates (PHAs) are a class of polymers that can be synthesized by microorganisms and are biodegradable, making them suitable candidates. The present study looks at the degradation properties of two PHA polymers: polyhydroxybutyrate (PHB) and polyhydroxybutyrate-co-polyhydroxyvalerate (PHBV; 8 wt.% valerate), in two different soil conditions: soil fully saturated with water (100% relative humidity, RH) and soil with 40% RH. The degradation was evaluated by observing the changes in appearance, chemical signatures, mechanical properties, and molecular weight of samples. Both PHB and PHBV were degraded completely after two weeks in 100% RH soil conditions and showed significant reductions in mechanical properties after just three days. The samples in 40% RH soil, however, showed minimal changes in mechanical properties, melting temperatures/crystallinity, and molecular weight over six weeks. By observing the degradation behavior for different soil conditions, these results can pave the way for identifying situations where the current use of plastics can be replaced with biodegradable alternatives.

Block copolymers generally have peculiar morphological characteristics, such as strong phase separation. They have been actively applied to polymer electrolyte membranes for proton exchange membrane fuel cells (PEMFCs) to obtain well-defined hydrophilic regions and water channels as a proton pathway. Although molecular simulation tools are advantageous to investigate the mechanism of water channel formation based on the chemical structure and property relationships, classical molecular dynamics simulation has limitations regarding the model size and time scale, and these issues need to be addressed. In this study, we investigated the morphology of sulfonated block copolymers synthesized for PEM applications using a mesoscale simulation based on the dynamic mean-field density functional method, widely applied to investigate macroscopic systems such as polymer blends, micelles, and multi-block/grafting copolymers. Despite the similar solubility parameters of the monomers in our block-copolymer models, very different morphologies in our 3D mesoscale models were obtained. The model with sulfonated monomers, in which the number of sulfonic acid groups is twice that of the other model, showed better phase separation and water channel formation, despite the short length of its hydrophilic block. In conclusion, this unexpected behavior indicates that the role of water molecules is important in making PEM mesoscale models well-equilibrated in the mesoscale simulation, which results in the strong phase separation between hydrophilic and hydrophobic regions and the ensuing well-defined water channel. PEM synthesis supports the conclusion that using the sulfonated monomers with a high sulfonation degree (32.5 mS/cm) will be more effective than using the long hydrophilic block with a low sulfonation degree (25.2 mS/cm).

This study illustrated the potential applications of thermoresponsive poly(N-isopropylacrylamide) (PNIPAm) grafted nylon membranes with different grafting yields and grafting architecture. The thermoresponsive gating performance at temperatures below and above the lower critical solution temperature (LCST) of PNIPAm (32 °C) were demonstrated. The linear PNIPAm-grafted nylon membrane exhibited a sharp response over the temperature range 20–40 °C. The grafting yield of 25.5% and 21.9%, for linear and crosslinked PNIPAm respectively, exhibited highest thermoresponsive gating function for water flux and had a stable and repeatable “open-closed” switching function over 5 cycle operations. An excellent oil/water separation was obtained at T < 32 °C, at which the hydrophilic behavior was observed. The linear PNIPAm-grafted nylon membrane with 35% grafting yield had the highest separation efficiency of 99.7%, while PNIPAm structures were found to be independent of the separation efficiency. In addition, the membranes with thermoresponsive gas permeability were successfully achieved. The O2 and CO2 transmission rates through the PNIPAm-grafted nylon membranes decreased when the grafting yield increased, showing the better gas barrier property. The permeability ratio of CO2 to O2 transmission rates of both PNIPAm architectures at 25 °C and 35 °C were around 0.85 for low grafting yields, and approximately 1 for high grafting yields. Ultimately, this study demonstrated the possibility of using these thermoresponsive smart membranes in various applications.

Here we suggest a simple and novel method for the preparation of a high-performance self-humidifying fuel cell membrane operating at high temperature (&gt, 100 °C) and low humidity conditions (&lt, 30% RH). A self-humidifying membrane was effectively prepared by laminating together proton and anion exchange membranes composed of acceptor-doped SnP2O7 composites, Sn0.9In0.1H0.1P2O7/Sn0.92Sb0.08(OH)0.08P2O7. At the operating temperature of 100 °C, the electrochemical performances of the membrane electrode assembly (MEA) with this heterojunction membrane at 3.5% RH were better than or comparable to those of each MEA with only the proton or anion exchange membranes at 50% RH or higher.

Here we suggest a simple and novel method for the preparation of a high-performance self-humidifying fuel cell membrane operating at high temperature (>100 °C) and low humidity conditions (

Succulents are ornamental plants that are popularly used in landscaping and as potted plants. Miniatureplants that are planted in miniature pots for small spaces or tables, or in elaborateaccessories such as key chains, key holders or hanging pots, have recently become more popular. Their unique characteristics and aesthetic appeal have increased their demand especially for those species that do not grow extensively during transport or for special cases in which they are placed into tiny containers to be used in key chains. This study investigated the effects of the plant growth inhibitors chlormequat, paclobutrazol, and daminozide, on two Echeveria species, Echeveria ‘A Grimme One’ and Echeveria ‘Little Rose’. Results revealed that the plant growth inhibitors successfully controlled the growth of Echeveria species at specific concentrations. Among the inhibitors applied to the succulents, paclobutrazol at 100 ppm was found to be the most effective treatment for both the species.

Few studies have reported how temperature influences growth and development of succulents, including anthocyanin production, which could fetch better prices in the market, and understanding the factors influencing such pigments would benefit farmers. The present study investigated the effect of temperature (10°C, 20°C, and 30°C) on the growth, development, and anthocyanin concentrations in Echeveria agavoides and E. marcus. In E. agavoides, similar growth performance was observed at 10°C and 20°C based on plant height and diameter. However, subjecting the species to a high temperature of 30°C resulted in a decrease in plant height. In E. marcus, optimal growth performance was observed at 20°C. Different temperatures did not significantly affect succulent quality and color hues. Only L* values were significantly different among the Hunter’s Lab values. Similar results were observed following anthocyanin and image analyses, both of which were not significantly affected by temperature. However, an intense red pigment was observed at 20°C compared with the green pigment observed at 10°C and 30°C based on the image analysis. The results suggest that temperature influences growth, development, and anthocyanin content of Echeveria succulents, and 20°C could be the optimal temperature for the cultivation of the species.

This study explores four core vocational development programmes for former Korean elite athletes that were designed to develop their linguistic and cross-cultural competencies and professional know...

In this study, blended anion exchange membranes were prepared using polyphenylene oxide containing quaternary ammonium groups and polyvinylidene fluoride. A polyvinylidene fluoride with high hydrophobicity was blended in to lower the vanadium ion permeability, which increased when the hydrophilicity increased. At the same time, the dimensional stability also improved due to the excellent physical properties of polyvinylidene fluoride. Subsequently, permeation of the vanadium ions was prevented due to the positive charge of the anion exchange membrane, and thus the permeability was relatively lower than that of a commercial proton exchange membrane. Due to the above properties, the self-discharge of the blended anion exchange membrane (30.1 h for QA–PPO/PVDF(2/8)) was also lower than that of the commercial proton exchange membrane (27.9 h for Nafion), and it was confirmed that it was an applicable candidate for vanadium redox flow batteries.

Optimization and miniaturization of existing electronic devices require the development of advanced nanostructured materials with high phase and structural purity. Over the past decade, barium titanate (BaTiO3) has attracted considerable attention due to its outstanding ferroelectric and dielectric properties. The present study involved the investigation of the phase transition and structural stability of tetragonal BaTiO3 nanopowders with pseudo-cubic phase using an in-situ high resolution and high temperature X-ray diffraction method. Under ambient conditions, the coexistence the tetragonal and cubic phases with weight fractions of 75.7% and 24.3%, respectively, was determined in BaTiO3. In the temperature range of 25 °C-300 °C, phase boundaries of BaTiO3 (180 nm in size) exhibiting several phases were detected. The phase transformation behavior, relative crystal phase content, lattice parameters, crystallite size, and tetragonality of the BaTiO3 nanopowders were established by the Rietveld refinement method at the onset temperature from 25 °C to 300 °C. Up to 150 °C, the nanopowders exhibited a complete transition of the cubic phase. Additionally, a complete tetragonal to cubic transformation was accomplished by a decrease of tetragonality at 125 °C and an increase in the crystallite size at 300 °C.

Despite significant advancements in reinforcing material-embedded structural adhesives, the industry still hesitates to employ the new technologies in their production line. In this communication, we investigate what critically hampers the practical application of newly developed reinforcing material-embedded structural adhesives to the industry, and analyze the factors impeding their commercialization from an economic perspective. By dividing mechanical strengths of adhesives by input cost, e.g., material cost and processing cost, we propose an evaluation index that can assess cost effectiveness of adhesives in terms of materials and processing costs, respectively. We found that the cost mainly affecting the impediment of employing reinforcing materials in structural adhesives is the processing cost that mostly consists of labor cost and electricity fees while the materials cost increase has a negligible impact on their cost effectiveness. Based on our analysis considering current materials and processing costs, we finally suggest how much the processing cost needs to be reduced and what the target achievement in mechanical strength enhancement should be in order to cross the cost effectiveness of commercialized structural adhesives.

Graphene reinforced aluminum matrix composites (GRAMCs) with improved thermal conductivity were prepared via a pH-controlled self-assembly process that involved adjusting the concentration of dispersed graphene oxide (GO) solutions. Uniform dispersion was achieved using GO coating on the aluminum (Al) surfaces. Graphene encapsulated Al powders (Al/GO) were sintered through spark plasma sintering (SPS) to prepare bulk composites, these were then analyzed to determine the thermal and mechanical properties. The density of the Al/GO composites was determined to be 99% or more compared to the theoretical density of pure Al. The Vicker&rsquo, s hardness and thermal conductivity increased by about 47% and 15% more than the pristine Al bulks. These processes can improve properties of the thermal interface between GO and Al, enabling uniform coating without a crosslinking agent. An Al/GO composite, fabricated through the pH-controlled self-assembly process, should be useful for various applications requiring to high thermal conductivity.

This study describes the use of poly(phenylene oxide) polymer-based ion-exchange polymers, polystyrene-based ion-exchange particles and a porous support for fabricating bipolar membranes and the results of an assessment of the applicability of these materials to water splitting. In order to achieve good mechanical as well as good ion-exchange properties, bipolar membranes were prepared by laminating poly(phenylene oxide) and polystyrene based ion-exchange membranes with a sulfonated polystyrene-block-(ethylene-ran-butylene)-block-polystyrene) (S-SEBS) modified interface. PE pore-supported ion-exchange membranes were also used as bipolar membranes. The tensile strength was 13.21 MPa for the bipolar membrane which utilized only a cation/anion-exchange membrane. When ion-exchange nanoparticles were introduced for high efficiency, a reduction in the tensile strength to 6.81 MPa was observed. At the same time, bipolar membrane in the form of a composite membrane using PE support exhibited the best tensile strength of 32.41 MPa. To confirm the water-splitting performance, an important factor for a bipolar membrane, pH changes over a period of 20 min were also studied. During water slitting using CA-P-PE-BPM, the pH at the CEM part and the AEM part changed from 5.4 to 4.18 and from 5.4 to 5.63, respectively.

In this study, thermally induced phase separation (TIPS) was used to fabricate a water treatment membrane composed of poly(vinylidene fluoride) (PVDF) and silica. Dioctyl phthalate (DOP) and dibutyl phthalate (DBP) were used as diluents. Crystallization temperature, cloud point, and morphology were observed to investigate the conditions of PVDF/silica/diluent membrane preparation. SEM revealed that the porosity of the membranes was increased with an increase in silica content. Phase diagram and morphology results revealed that 50 wt% PVDF+silica with a PVDF:silica weight ratio of 4.5:1 is the best composition for manufacturing a porous membrane.

This study investigated ion exchange membranes for application to seawater desalination processes. This can provide better energy efficiency than the conventional reverse osmosis process. In this experiment, the problem of decreasing ion exchange performance when the ion exchange composite membrane was prepared could be improved through nanoparticles. The nanoparticle added ion exchange hybrid membrane showed ion exchange capacity similar to that of the conventional pristine film. In addition, the polymer having a high ion exchange capacity has poor mechanical strength, but has excellent mechanical strength of 30 MPa or more by the introduction of a polyethylene support.

Anion exchange membranes (AEMs) play prominent role in addressing alkaline fuel cell efficiency and cost. Great deal of efforts has been made in the past, particularly during the last couple of years to reach AEMs with high hydroxide conductivity, good chemical/thermal/mechanical stability, fuel cross-over resistance and low cost. The purpose of this review is to summarize and discuss the progress on the development of different AEMs for alkaline fuel cells over the last three years. The alternative AEMs based on the modified synthetic and sustainable polymers, organic/inorganic hybrid materials and additives are reviewed in the context of AEM materials.

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.