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Recently, functional molecules such as Polydopamine (PDA), Hyaluronic Acid (HA) and heparin have been widely studied in the field of surface modification of magnesium (Mg) alloy stents for better degradation behavior and biocompatibility, but their further application is limited by undesirable anticoagulant function, uncontrollable degradation and easy bleeding, respectively. Regarding to this consideration, a magnesium Fluoride/Polydopamine/Sulphonated hyaluronic acid (MgF2/PDA/S-HA) composite coating was successfully prepared by applying S-HA with sulfur content of 9.71 wt% on the surface of ZE21B alloy in this study. The results showed that the composite coating with a unique mesh structure not only inherited the anticoagulant effect of sulfonic acid group and the excellent cyto-compatibility of S-HA with high sulfur content, but also significantly improved the corrosion performance of ZE21B alloy. These results indicate a great application potential of the composite coating in the field of cardiovascular biomaterials.

Sulfonic-containing UiO-66 and MIL-101 MOF materials, prepared by direct synthesis with a sulfonic acid-including benzene dicarboxylate (SO3H-BDC) linker, have been evaluated as acid catalysts in Friedel–Crafts acylation of anisole with acetic anhydride. The catalytic activity of these materials was compared to other conventional acidic sulfonic heterogeneous catalysts, such as commercial Nafion-SAC-13 and Amberlyst-15. The catalytic performance of MOF materials was significantly dependent on their textural properties and the availability of sulphonic acid groups. MIL-101-SO3H material displayed a remarkable anisole conversion and specific activity per sulfonic acid centre due to its open structure and multimodal pore size distribution. The inherent properties of MIL-101-SO3H material allowed a more sustainable catalyst regeneration than those used for conventional heterogeneous catalysts due to the deposition of reagents and products, in particular poly-acetylated compounds. MIL-101-SO3H proved an easy recovery and reusability in successive runs without any loss of activity. These promising results evidenced the potential of MIL-101-SO3H as an alternative catalyst for acid-catalyzed reactions.

The popularity of coffee as a beverage has led to a large amount of spent coffee waste worldwide, of which spent coffee ground (SCG) is one of the most heavily generated residues. Considering the environmental and social pressure to reduce pollution and increase sustainability, it is important to explore the application of SCGs in the field of renewable energy. Polysaccharides account for the most abundant components in SCGs, mainly including hemicellulose, cellulose, lignin, fat, and dietary fiber. Herein, SCG is utilized as an alternative to commercial cellulose to produce reducing sugars via hydrolysis using a sulfonated silica catalyst. Sulfonated silica catalysts are heterogeneous catalysts with advantages comprising easy separation and high recyclability. In this study, a simple and template-less method to synthesize mesoporous silica substrates by employing an in-situ microbubble generator was developed. The microbubbles generated during silica synthesis enhanced the structural properties and production yield of the silica spheres. The produced silica substrates were subjected by hydrothermal sulfonation, which resulted in a total acid density of 5.49 mmol g−1 and sulfonic acid density of 0.87 mmol g−1. The total reducing sugar yield of 31.4% was achieved by SCG hydrolysis over microbubble-assisted sulfonated silica catalysts (SSCs) at 150 ℃ for 15 h, with C6 sugars including mannose and galactose as the main products. The recyclability of SSCs was determined with a reusability test under identical coffee hydrolysis conditions. A reducing sugar yield of 96% could be maintained, which verified the high chemical structural stability of SSCs during the synthesis employing the bubble generator and hydrothermal sulfonation process. For comparison, the SSCs prepared by stirring at room temperature without a micro-bubble generator showed a relatively lower sugar yield of 24% under the same hydrolysis conditions. Therefore, this novel microbubble-assisted synthesis described herein is a promising economical, eco-friendly, and simple technique for fabricating structural silica templates as catalyst supports for biomass conversion.

Perovskite solar cells (PSCs) have become a promising photovoltaic (PV) technology. Meanwhile, developing an electron transport layer (ETL) has been an effective way to promote the power conversion efficiency (PCE) of PSCs. Here, a 4-morpholine ethane sulfonic acid sodium salt (MES Na+) doped SnO2 ETL is utilized in planar heterojunction PSCs. The results show that the MES Na+ doped ETL can improve the crystallinity, and absorbance of perovskite films, and passivate interface defects between the perovskite film and SnO2 ETL. The doping effect accounts for the enhancement of conductivity and the decreasing work function of SnO2. When 10 mg mL-1 MES Na+ was added to the SnO2 precursor solution, the device showed the best performance Jsc, Voc, and FF of the PSCs values, which were 23.88 mA cm-2, 1.12 V and 78.69%, respectively, and the PCE was increased from 17.43% to 21.05%. This doping ETL strategy provides an avenue for defect passivation to further increase the efficiency of perovskite solar cells.

Acetalization of glycerol with hexanal was studied over sulfonic acid-functionalized mesoporous silica (SBA-15), at 70 oC. The product obtained were (2-pentyl-1,3-dioxolan-4-yl)methanol and 2-pentyl-1,3-dioxan-5-ol. Materials with different amounts of sulfonic acid groups were prepared. The support functionalization was achieved by the introduction of 3-(mercaptopropyl)trimethoxysilane onto the surface of these materials by grafting technique. The [SO3H]-SBA-15 catalysts were characterized by nitrogen adsorption at 77 K, X-ray diffraction, SEM and titrations. All the catalysts were active in the studied reaction being the [SO3H]3-SBA-15 the best one. It was observed that the reaction rate increase with the amount of sulfonic acid groups on SBA-15 until a maximum. With high amounts of sulfonic groups, a decrease of activity is observed. Good values of selectivity to (2-pentyl-1,3-dioxolan-4-yl)methanol were obtained with mesoporous silicas anchored sulfonic acid groups. Catalytic stability of the [SO3H]3-SBA-15 was evaluated by performing consecutive batch runs with the same catalyst sample. The material showed a good catalytic stabilization.

Interest in DES is leveling up with increasing need for providing additional knowledge on their behavior and comparability with other type of solvents. In- addition cheap and environmental safe DES are emerging as attractive solvents in many applications. A novel deep eutectic solvent was made by simple mixing different mole ratios of sulfonic acid with acetamide. The effect of mole ratio on the interaction between the DES components was observed by ATR-IR with gradual color changes of formed DES. At 1 to 2 mol ratio respectively a different vibrational interactions is recorded. The least viscose DES of sulfonic acid with acetamide (1:6) shows temperature dependents of conductivity, viscosity and density with similar behaviors of other DESs. The cyclovolatammograms of 1:6 mol ratio of DES or its copper sulfate solution were measured and indicate a one-step reduction and oxidation of copper (Cu+2 to Cu0). Less than 75 nm copper was electrodeposited from its solution in DES with round particles on zinc substrate. DES and its solution with Copper sulfate was investigated by UV-visible spectroscopy suggested an Oh coordination of Cu2+ to DES.

Design and construction of a matrix with specific adsorption on the target compounds can effectively reduce the detection limit of surface-assisted laser desorption/ionization time-of-flight mass spectrometry (SALDI-TOF MS) analysis. Sulfonic acid functionalized hierarchical porous covalent organic frameworks (H-COF-SO3H) was synthesized by defect-structure and post-modification method, and then used as matrix and adsorbent for the determination of quaternary ammonium herbicides paraquat (PQ) and diquat (DQ). N2 adsorption–desorption experiments confirmed that H-COF-SO3H possesses hierarchical porosity with pore widths concentrated at 1.3,1.5, and 2.8 nm. The strong UV absorption at 200–450 nm and good thermal stability made H-COF-SO3H being a promising matrix without background interference. H-COF-SO3H can efficiently enrich PQ and DQ via electrostatic attraction, and the key role of -SO3H group on specific adsorption was confirmed by density functional theory (DFT) calculations. The limits of detection (LODs) for PQ and DQ with H-COF-SO3H enrichment were 0.5 and 0.1 ng·mL−1, respectively, which were 20 and 60 times higher than those without H-COF-SO3H enrichment, respectively. The spiked recoveries of PQ and DQ for the three food samples were 92.0–113.2% and 80.1–102.6% with RSDs of 2.2–9.2% and 2.0–8.7%, respectively. This work provides an analyte-oriented approach for fabricating SALDI-TOF MS matrix.

Covalent immobilization of propyl sulfonic acid groups on the surface of magnetic graphene oxide is reported as an efficient magnetically recoverable solid acid catalyst for the conversion of fructose into 5-hydroxymethylfurfural (5-HMF). The obtained nanocomposite has advantages of both graphene oxide (high surface area) and magnetic nanoparticles (fast and facile separation by a magnet). The numerous reaction parameters including solvent, reaction time, temperature, and amount of catalyst were optimized to attain maximum yield of 5-HMF. The results revealed that fructose could be effectively transformed into 5-HMF with a yield of 87% under the optimized reaction conditions. The catalyst could be magnetically separated from the reaction mixture. Moreover, the catalyst exhibited high stability and could be reused for at least five times without a discernible loss of catalytic performance.

Recently, SnO2-based perovskite solar cells (PSCs) have become more promising than traditional-material-based PSCs because of their simple low-temperature solution approach and low cost; meanwhile, the high-temperature process of mesoporous TiO2-based PSCs still offers a higher power conversion efficiency (PCE). In planar-based PSCs, nonradiative recombination of electron-hole pairs at the SnO2/perovskite interface leads to a loss of potential and a reduced PCE. Here, the SnO2-SDBS electron transport layer (ETL) is employed in PSCs to depress the defects of the SnO2 layer and the grain boundaries of the perovskite film. The surfactant SDBS was used as a wetting agent for SnO2 nanoparticles, to improve dispersibility. In addition, the benzene sulfonic acid group of SDBS attached to the SnO2-SDBS film can control the process of perovskite crystallization, producing a vertically aligned growth and large-grain perovskite layer. Finally, the open-circuit voltage was improved from 1.038 to 1.077 V and the PCE increased from 18.01% to 19.25% in the devices using the SnO2-SDBS ETL. The incorporation of SnO2-SDBS as an ETL paves the way to further performance enhancements of SnO2-based planar PSCs.

Ultra-low permeable reservoirs are considered unconventional reservoirs with a permeability of less than two mD. Thereby, oil production by conventional techniques has some problems and challenges rather than other types of reservoirs. This paper aimed to experimentally investigate different injectivity scenarios such as water alternating gas injection, surfactant flooding (anionic and cationic surfactants), and carbon dioxide injection both as continuous and cyclic, and carbonated water injection. To do this, surfactant and carbon dioxide concentration should be optimized first to provide efficient results. According to the results of this study, LABSA (linear alkylbenzene sulfonic acid) and CTAB (cetyl trimethyl ammonium bromide) have their optimum concentration at 300 and 350 ppm, which is indicated that after this concentration, there is no significant alteration in IFT (Interfacial tension) The maximum oil recovery factor for LASBA and CTAB is 46 and 42%, respectively. 750 mg/L of CO2 has provided the highest oil recovery (54.5%), and by the increase of CO2 concentration, there is no significant change in oil production. The maximum oil recovery increase by a surfactant (LABSA), continuous CO2 injection, cyclic CO2 injection, water alternating gas injection, and carbonated water (CW) injection is about 15%, 24.5%, 30%, 27%, and 34%, respectively. The highest oil recovery factor for secondary CW injection and CW after brine injection is about 68% and 63%, which indicated the proper efficiency of secondary CW injection in ultra-low permeable reservoirs.

Chemical functionalization of chitosan biopolymer and chitosan-magnetite nanocomposite was performed with sulfonic acid functional groups to achieve new solid acid materials. The sulfonic acid functional groups were created through the ring opening nucleophilic reaction of amine groups of chitosan with 1,4-butane sultone. Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopies (XPS) verified the successful sulfonic acid functionalization of chitosan. The obtained sulfonic acid functionalized chitosan-magnetite nanocomposite showed superparamagnetic properties according to the vibrating sample magnetometry analysis and exhibited magnetic separation feature from dispersed mixtures. Nitrogen adsorption-desorption analysis indicated the increase in surface area after formation of chitosan-magnetite nanocomposite and functionalization with sulfonic acid. Both of the prepared solid acids exhibited high catalytic activities in the acid-catalyzed acetic acid esterification with n-butanol and benzaldehyde acetalization with ethylene glycol as model reactions. Furthermore, they can be reused several times without considerable loss of their activities.

Synthesis of surfactants based on linear alkylbenzenesulfonates is a complex multi-stage process that includes the following stages: alkanes dehydrogenation on Pt-containing catalyst, dienes hydrogenation on Ni-containing catalyst, HF-catalyzed alkylation of benzene with alkenes, and sulfonation of linear alkylbenzenes (LAB) with sulfur trioxide in a film reactor yielding alkylbenzene sulfonic acid (ABSA). When developing mathematical models of multi-stage processes it is necessary to consider the contingency of the apparatuses in the chemical-technological system. The design of the sulfonation reactor, as well as the feedstock composition and the dehydrogenation unit performance, i.e., the LAB flowrate to sulforator, significantly affects the ABSA synthesis efficiency. The studies were performed using the unsteady mathematical models of conjugated dehydrogenation and sulfonation processes. As a result, we determined the optimal design of the sulfonation reactor with number of tubes n = 40 and diameter d = 43 mm. We also outlined the preferred method for increasing the ABSA yield by switching to a double-reactor alkane dehydrogenation scheme with a flowrate of 100 m3/h for two dehydrogenation reactors. This increases yield of alkenes and LAB by 71 %wt.

Conversion of saccharides to 5-hydroxymethylfurfural is one of the fundamental steps in the synthesis of biodiesel. In this work, we report on the influence of Lewis and Bronsted acidic sites on metal-free graphitic carbon nitride catalysts for the conversion of monosaccharides to 5-hydroxymethylfurfural. We have examined the Lewis acidic sites by doping boron onto graphitic carbon nitride, and under optimal conditions, a maximal 91% yield of 5-hydroxymethylfurfural has been obtained from fructose. Subsequently, the boron doped graphitic carbon nitride was functionalized with Bronsted acidic group to prepare sulfonic acid functionalized boron doped graphitic carbon nitride, which possesses both Lewis and Bronsted acidic sites. However, the use of sulfonic acid functionalized boron doped graphitic carbon nitride as catalyst resulted in a lower yield (78%) of 5-hydroxymethylfurfural from fructose. In addition, time-dependent nuclear magnetic resonance spectroscopic study, temperature-programmed desorption study, and green metrics calculations have been performed to substantiate our findings. Overall, this work provides valuable insights on the influence of Lewis and Bronsted acidic sites on graphitic carbon nitride for biomass conversion reactions.

Mesoporous activated carbon from sunflower shells (SAC) modified with sulfonic acid groups (SACSO3H-XX) was synthesized by grafting the sulfonic groups on the carbon surface to produce novel heterogeneous and reusable solid acid catalysts. The mesoporous carbon was prepared by chemical (H3PO4) and thermal (600 °C) activation of sunflower seed shells. Four materials with increasing SO3H content (SACSO3H-5, SACSO3H-10, SACSO3H-15, and SACSO3H-20) were obtained using rising chlorosulfonic acid:SAC ratios. They were texturally and physicochemically characterized by SEM-EDX, BET, FT-IR, and TGA-DSC. Potentiometric titration with n-butylamine technique was used to evaluate their acidic properties. The results showed that both the acid strength and the number of acid sites increased with the SO3H content in the SACSO3H-XX samples. The FT-IR spectra of SACSO3H-XX samples confirmed the successful functionalization of SAC with the sulfonic acid group. TGA-DSC diagrams of SACSO3H-20 showed that the elimination of the sulfonic groups takes place in the range 250–350 °C. The activity and selectivity of SACSO3H-XX in the esterification reaction of itaconic acid with absolute ethanol to form the diester derivative depended strongly on their acidic properties. Furthermore, the effective separation of the product combined with the use of a recyclable catalyst resulted in a clean and environmentally friendly strategy for the synthesis of diethyl itaconate, a bioproduct of relevance to the biorefinery industry.

A type of sulfonated covalent organic framework nanosheets (TpPa-SO3H) was synthesized via interfacial polymerization and incorporated into sulfonated poly (ether ether ketone) (SPEEK) matrix to prepare proton exchange membranes (PEMs). The densely and orderly arranged sulfonic acid groups in the rigid skeleton of the TpPa-SO3H nanosheets, together with their high-aspect-ratio and well-defined porous structure provide proton-conducting highways in the membrane. The doping of TpPa-SO3H nanosheets led to an increased ion exchange capacity up to 2.34 mmol g−1 but a 2-folds reduced swelling ratio, remarkably mitigating the trade-off between high IEC and excessive swelling ratio. Based on the high IEC and orderly arranged proton-conducting sites, the SPEEK/TpPa–SO3H–5 membrane exhibited the maximum proton conductivity of 0.346 S cm−1 at 80 °C, 1.91-folds higher than the pristine SPEEK membrane. The mechanical strength of the composite membrane was also improved by 2.05-folds–74.5 MPa. The single H2/O2 fuel cell using the SPEEK/TpPa–SO3H–5 membrane presented favorable performance with an open voltage of 1.01 V and a power density of 86.54 mW cm−2.

The deterioration of the environmental situation has led to the need to restructure the world’s power industry, and clean renewable power sources are coming to the forefront. This review deals with recent advances in the development of promising ion-exchange membrane materials for two types of application that have been intensely developing recently, namely, hydrogen energy and reverse electrodialysis. Special attention is paid to the comparison of two properties of membranes, conductivity and selectivity, that are competing but fundamentally important in both areas. Perfluorinated sulfonic acid membranes now play a dominant role in hydrogen power engineering, as they provide not only high proton conductivity but also chemical stability and low gas permeability. The review also covers other types of membrane materials, including anion exchange membranes, polybenzimidazoles and hybrid membranes containing inorganic nanoparticles that have been actively developed in recent years. The milder operating conditions of membranes in reverse electrodialysis units allow one to use less expensive non-perfluorinated membranes, including grafted ones. It is of note that in devices of this type, the selectivity of membranes to the transfer of oppositely charged ions is a more important parameter.

Copolymers of poly(methyl methacrylate)-co-poly (2-acrylamido-2-methyl-1-propane sulfonic acid (PMMA-co-PAMPS) have been prepared via radical polymerization with different MMA to AMPS mol ratio and blended with polyvinylidene fluoride (PVDF) and sulfonated PVDF (S-PVDF) in a different weight ratio to prepare proton exchange membranes (PEMs) by simple solution casting method for fuel cells application (PEMFCs). Five different PEMs have been prepared from only PMMA-co-PAMPS, blending PMMA-co-PAMPS with PVDF, and also by blending PMMA-co-PAMPS with S-PVDF to get the suitable membrane for PEMFCs application. We have also studied the effect of PVDF and S-PVDF in the blend membranes on the water uptake, mechanical stability, thermal stability, proton conductivity (Km), and methanol permeability ( P M ) properties. PEMs prepared by blending with S-PVDF exhibited high Km and low P M value. PEM-5 membrane prepared by blending S-PVDF with PMMA-co-PAMPS (30:70 w/w) exhibited Km at room temperature 5.7 × 10−2 S/cm, PM value 5.24 × 10−7 cm2/s and maximum power density 477 mW/cm2. This P M value is much lower than that of the Nafion® 117 membrane (22 × 10−7 cm2/s). This low P M , high Km and high selectivity make the S-PVDF blend membranes a good candidate in PEMFCs or direct methanol fuel cells (DMFCs) application.

Green and recyclable solid acid catalysts are in urgent demand as a substitute for conventional liquid mineral acids. In this work, a series of novel sulfonic acid-functionalized core-shell Fe3O4@carbon microspheres (Fe3O4@C-SO3H) have been designed and synthesized as an efficient and recyclable heterogeneous acid catalyst. For the synthesis, core-shell Fe3O4@RF (resorcinol-formaldehyde) microspheres with tunable shell thickness were achieved by interfacial polymerization on magnetic Fe3O4 microspheres. After high-temperature carbonization, the microspheres were eventually treated by surface sulfonation, resulting in Fe3O4@C-x-SO3H (x stands for carbonization temperature) microspheres with abundant surface SO3H groups. The obtained microspheres possess uniform core-shell structure, partially-graphitized carbon skeletons, superparamagnetic property, high magnetization saturation value of 10.6 emu/g, and rich SO3H groups. The surface acid amounts can be adjusted in the range of 0.59–1.04 mmol/g via sulfonation treatment of carbon shells with different graphitization degrees. The magnetic Fe3O4@C-x-SO3H microspheres were utilized as a solid acid catalyst for the acetalization reaction between benzaldehyde and ethylene glycol, demonstrating high selectivity (97%) to benzaldehyde ethylene glycol acetal. More importantly, by applying an external magnetic field, the catalysts can be easily separated from the heterogeneous reaction solutions, which later show well preserved catalytic activity even after 9 cycles, revealing good recyclability and high stability.

A composite membrane comprising sulfonated polyether ether ketone (sPEEK) and polystyrene sulfonic acid functionalized micelle templated MCM-41 (PSSA-f-MCM-41) is realized as a potential alternative to the Nafion membrane for direct methanol fuel cells (DMFC). PSSA-f-MCM-41 incorporation in sPEEK leads to improvement in the physio-chemical properties such as ionic conductivity, methanol permeability, tensile strength, water uptake and ion exchange capacity. The methanol permeability of the composite membrane i.e. PSSA-f-MCM-41 (1.5 wt %)-sPEEK is reduced by 60% in comparison to pristine sPEEK. Moreover, the electrochemical selectivity of the aforesaid composite membrane is four times higher than sPEEK. The DMFC performance shows the peak power density of 147 mW cm−2 for the composite membrane which is higher than the pristine sPEEK and Nafion 117 membranes. Stability test for the composite membranes confirm less degradation in OCV in comparison to pristine sPEEK.

Side-chain optimized poly (2,6-dimethyl-1,4-phenylene oxide)-g-poly (styrene sulfonic acid) (PPO-g-PSSA) is designed with balanced water-resistance and sulfonation degree. The PPO-g-PSSA is synthesized by controlled atom-transfer radical polymerization (ATRP) from brominated poly (2,6-dimethyl-1,4-phenylene oxide) (PPO-xBr) and ethyl styrene-4-sulfonate and followed by hydrolysis. A series of PPO-g-PSSA are prepared possessing different bromination degree (x) of PPO-xBr and polymerization degree (m) of the side-chains and the water-resistances of the fabricated membranes are investigated. The results show that a PPO-g-PSSA at relatively low x (x 4) exhibits good balance between the water-resistance and the sulfonation degree. Namely, it displays suitable proton conductivity with compromised water-resistance. Moreover, a maximum ion exchange capacity (IEC) of 3.24 mmol g−1 is reached without the sacrifice of water-resistance. In addition, PPO-g-0.08PSSA-13 and PPO-g-0.14PSSA-4 are chosen characterized by thermogravimetric analysis, proton conductivities and mechanical properties. At 90% RH, the optimized PPO-g-0.08PPSA-13 possesses a proton conductivity of 37.9 mS cm−1 at 40 °C and 45.5 mS cm−1 at 95 °C, respectively.

Biodiesel is an attractive alternative to fossil fuels due to the energy and environmental concerns. In this paper, seven different multi –SO3H functionalized ILs based on the low-cost less-substituted amines, which contained massive sites for functionalization of sulfonic acid groups and further treatment of sulfonate-based anions, were prepared as catalysts with high acidity and desirable catalytic activity for the synthesis of biodiesel from the esterification of oleic acid with methanol. The physicochemical properties of these acidic ILs were characterized by a variety of analytical techniques such as FT-IR, EA, TGA, and the Bronsted acidity was well determined by UV–vis. Among the ILs prepared, [EDA-PS][P-TSA] showed the highest catalytic activity for esterification due to its high acidity and appropriate miscibility with reactants, with an ultrahigh 97.58% conversion of oleic acid under the optimum conditions (i.e. reaction time, 1.8 h; catalyst amount, 3 wt%; alcohol/acid molar ratio, 13:1, temperature 70 °C) acquired from the Box–Behnken response surface methodology. With the novel strategy of multi –SO3H modification on ILs, our catalyst had an approaching or even superior oleic acid conversion rate compared to other reported catalysts with considerably lower catalyst dosage and shorter reaction time. More importantly, it also exhibited high generality for converting various FFA feedstocks into biodiesel with considerable conversion within 93.59–94.33% under a rather lower catalyst dosage, which showed the valuable potential for converting low-cost oils into biodiesel from an economic and environmental perspective.

A few-layered MoS2 successfully grown on the nitrogen-doped carbon (NC) derived from zeolitic imidazolate framework (ZIF-8) via the hydrothermal method. A small portions of the obtained MoS2/NC composite blended with Poly (3, 4-ethylenedioxythiophene poly styrene sulfonic acid)PEDOT: PSS(as a conductive binder and utlized as counter electrode (CE) for dye-sensitized solar cells (DSSCs). The spin-coated MoS2/NC-PEDOT: PSS composite on Fluorine-doped Tin Oxide (FTO) glass not only possesses promissing catalytic ability toward the I 3 - / I - and [Co(bpy)3]2+/3+ redox mediators but also displayed considerable optical transparency in the visible range thus used to fabricate bi-facial DSSCs. The assembled bi-facial devices with MoS2/NC-PEDOT: PSS composite CEs showed an excellent power conversion efficiency (PCE) under both the front and the rear irradiations. The PCE of the device with 5% MoS2/NC-PEDOT: PSS composite CE and I 3 - / I - redox couple are 7.67 and 4.54%, under the front and rear irradiation respectively. Also, the values of the device with the same composite CE and [Co(bpy)3]2+/3+ redox mediator are 7.87 and 5.34% under the front and rear irradiation, respectively. The optimum performance of the devices with the prepared CEs and both redox systems are comparable with Pt-based devices. Thus, the MoS2/NC-PEDOT: PSS composite CEs are recommend being a promising Pt-free CEs for DSSCs.

Solid acid catalyst was produced from olive pomace (OP), characterized and used for the esterification of OP oil. OP was pyrolyzed, physical activated by steam and sulfonated using sulfuric acid. Commercial, coconut husk-based, activated carbon (CHAC) was also sulfonated for comparison. The activation has shown a significant increase in olive pomace activated carbon (OPAC) surface area by developing simultaneously its micro and meso-porosity. The sulfonation has further increased OPAC BET surface area to reach 618.18 m2/g and has changed its structure to become microporous. Sulfonation also removed tar residues and aliphatic hydrocarbons from OPAC’s surface. Tendencies observed with carbon CHAC, used for comparison, are slightly different with a mesoporosity development. Although its higher surface area (1227.01 m2/g), CHAC has fixed three times less sulfur than OPAC, which can be attributed to its higher hydrophobicity or pore distribution. Sulfur was mainly fixed in the form of sulfonic acid (SO3H). Esterification with methanol using produced solid catalysts decreased OPO acidity below the 2 mgKOH/g threshold after 5 h of reaction and reduced mono, di and triglycerides to levels close to the ones required by European norm EN14214.

To improve the wettability effect of coal seam water injection, and reduce dust production from the source, this paper proposes the preparation of three kinds of high-efficiency wetting enhancers. In this study, 2-acrylamide-2-methylpropionic sulfonic acid and itaconic acid were introduced into the polymer chain of sodium alginate in different combinations. Anionic surfactant sodium dodecyl sulfate and nonionic surfactant aliphatic alcohol polyoxyethylene ether were added in different proportions to obtain three kinds of enhancers. The three kinds of enhancers have good viscosity and fluidity, and the optimal emulsifier additive is determined by a surface tension test. The hydrophilic hydroxyl, carboxyl or sulfonic groups of enhancers were obtained by a Fourier-transform infrared experiment, which was beneficial to water absorption. The contact effect of different solutions on coal block was studied by a scanning electron microscopy experiment. An energy dispersive spectrometry experiment proved that the solution was well dispersed. Through reverse osmosis experiment and contact angle analysis, the wettability of different solutions was compared, and the best enhancers was obtained. The molecular dynamics simulation was used to verify the relationship between them, and finally the mechanism of action was deduced. It was proved that AMPS-IA/SA+SDS/AEO had better wettability. Thus, AMPS-IA/SA+SDS/AEO is an ideal enhancer for coal seam water injection.

Organic pollutants in electroplating wastewater can be removed by photodegradation, however the effect mechanism of heavy metal ions on photocatalytic activity still remains unknown. Herein, we firstly reported the self-assembly synthesis of titanium dioxide/reduced graphene oxide (TiO2/rGO) composites for phenol-4-sulfonic acid (PSA) removal, and investigated the effects of Cu2+ ions on photocatalytic efficiency. During the self-assemble process, rGO nanosheets were connected together to form network macropores, and simultaneously induced the deposition of hierarchically nanostructured TiO2 microspheres. The synergetic effects of TiO2 microspheres and rGO nanosheets improved the photocatalytic activity by enhancing light adsorption ability, stabilizing electron-hole separation and decreasing band gap energy. The Cu2+ ions in wastewater showed positive and negative effects on PSA photodegradation. In the photocatalytic reaction, the electron-induced reduction reaction of Cu(II) into Cu(0) or Cu(I) took place, which inhibited electron-hole recombination and thus enhanced photocatalytic activity. However, the high chemical stability of PSA-Cu(II) complex compounds held back PSA photodegradation. The appropriate concentrations of Cu2+ ions at around 25 mg/L accelerated PSA photodegradation over TiO2/rGO composites. The PSA degradation into CO2 and H2O was performed by using hydroquinone, benzoquinone and maleic acid as degradation intermediates. Hence, TiO2/rGO composites are novel multifunctional photocatalysts to purify electroplating wastewater.

A hydrocarbon polymer of poly (isatine-phenylene) (PiP), which was synthesized in a super acid-catalyzed polyhydroxy alkylation reaction, was introduced as an alternative conducting material in PEMFC. The sulfonimide acid in super gas-phase acidity was used to modify the sulfonic PiP (SPiP) to improve the dimensional stability and enhance proton conductivity. The PiP (SIPiP) showed considerably higher ion exchange capacity (IEC) and proton conductivity than SPiP controls. All the synthesized polymers revealed excellent thermal stability (

A series of novel poly (2,5-benzimidazole)-grafted montmorillonite (ABPBI-MMT) and sulfonated poly vinyl alcohol (SPVA) composite membranes have been prepared via solution casting method which were further doped with phosphoric acid. The structure of composite membranes has been studied using FTIR, XRD and SEM. The effect of ABPBI-MMT on the water uptake (WU), proton conductivity, mechanical and chemical stability of the resultant membranes has been examined before and after phosphoric acid (PA) doping. This study flaunted that the introduction of ABPBI-MMT into SPVA decreased the WU of pristine polymer matrix as a result of acid-base interaction between the sulfonic acid and benzimidazole groups. However, after PA doping, the WU of the membranes has tremendously boosted. Initially, the influence of ABPBI grafted clay on proton conductivities of SPVA membranes has been studied along with the analysis of PA doping effect on membrane conductivity with fuel cell performance. Furthermore, the proton conductivities of PA doped, and un-doped composite membranes have been studied at high temperatures ranging from 100 to 140 °C under 0% RH. The PA-doped composite membranes show enhanced conductivity values (0.0075 Scm−1) at 140 °C even with 0% RH. The maximum proton conductivity of 0.157 Scm−1 and peak power density of 1100 mWcm−2 have been obtained at 140 °C under 100% RH with 15PBMPP composite membranes. These results indicate that the newly prepared PA-doped PEMs are an excellent candidates for high-temperature PEM fuel cell application.

Pyrrolidone carboxypeptidases (Pcps) (E.C. 3.4.19.3) can cleave the peptide bond adjacent to pyro-glutamic acid (pGlu), an N-terminal modification observed in some proteins that provides protection against common proteases. Pcp derived from extremely thermophilic Fervidobacterium islandicum AW-1 (FiPcp), that belongs to the cysteine protease family, is involved in keratin utilization under stress conditions. Although an irreversible oxidative modification of active cysteine to its sulfonic acid derivative (Cys-SO3H) renders the enzyme inactive, the molecular details for the sulfonic acid modification in inactive Pcp remain unclear. Here, we determined the crystal structure of FiPcp at 1.85 A, revealing the oxidized form of cysteine sulfonic acid (C156–SO3H) in the catalytic triad (His-Cys-Glu), which participates in the hydrolysis of pGlu residue containing peptide bond. The three oxygen atoms of cysteine sulfonic acid were stabilized by hydrogen bonds with H180, carbonyl backbone of Q83, and water molecules, resulting in inactivation of FiPcp. Furthermore, FiPcp demonstrated a unique 139KKKK142 motif involved in inter-subunit electrostatic interactions whose mutation significantly affects the thermostability of tetrameric FiPcp. Thus, our high-resolution structure of the first inactive FiPcp with irreversible oxidative modification of active cysteine provides not only the molecular basis of the redox-dependent catalysis of Pcp, but also the structural features of its thermostability.

In this study, catalytic activity and deactivation mechanism of a carbon-based solid-acid catalyst in the esterification of oleic acid and methanol were investigated. The experimental results showed that the S150-4 catalyst, prepared by sulphonating at 150 °C for 4 h, yielded the highest sulfonic acid density. The conversion yield reached 97.98% under the optimum esterification conditions (i.e. catalyst loading, 10 wt%; methanol/oleic acid molar ratio, 8:1; reaction temperature, 65 °C; reaction time, 8 h) and decreased to 79.19% after four cycles. In the first batch of esterification, the formation of sulfonic esters was the main reason for the deactivation of the catalyst, whereas the leaching of sulphur was the main contributor in the second to fourth batches. Therefore, it is believed that reducing the leaching of sulphur and the formation of sulfonic esters by changing the addition method of methanol is an effective method to extend the service life of the catalyst.

The catalytic activity of titanium dioxide (TiO2) supported SO3H (n-TSA) as a solid heterogeneous nanocatalyst was studied for the construction of 2-(substituted phenyl)-3-(5-methylisoxazol-3-yl)thiazolidin-4-ones by the solvent-free three-component reaction of substituted aldehydes, thioacids and 3-amino-5-methyl-isoxazole without using volatile solvents. Short reaction time with excellent yields, cost effective, easy workup process and recyclability of catalyst are the notable green reaction credentials of the present eco-friendly method.

An adsorbent Stearyl Alcohol (SA) - grafted- epichlorohydrin (E) -grafted- aminoproypyl silanetriol (APST) was synthesized, functionalized with sulfonic acid by sulfonation process [(SA-g-E)-g-APST/ SO3H]. The characterization of the adsorbent material was done using FTIR, XRD, SEM and TGA analyses. Adsorption behaviour of bovine serum albumin (BSA) was investigated using batch adsorption experiments. Adsorption efficiency was found to be extreme at pH 4.5. Kinetic studies revealed the suitability of pseudo-second-order model and adsorption equilibrium was attained within 3 h. On studying the rate limiting step, film diffusion process proved to be the best fit. Considering different isotherms, Sips isotherm model proved to be the best acceptable with a maximum adsorption capacity of 35.12 mg/g at 303 K. The favorability of the adsorption process was studied by calculating the separation factor (RL) and the results were found to be positive. Thermodynamic studies pronounce the spontaneous nature of adsorption, having maximum entropy in the system. Revival studies were done using 0.1 M Na2CO3 as the desorbing agent. The desorption experiment was carried out for over six cycles - showed the repeatability and regeneration capability of the adsorbent.

Composite proton conducting membranes were successfully synthesized from chitosan, poly (vinyl alcohol) and sulfonic acid-functionalized silica nanoparticles. Sulfosuccinic acid (SSA) and glutaraldehyde were used as double crosslinking agents, where the effect of SSA content on membrane properties, including water vapor absorption, water uptake, ion exchange capacity, and proton conductivity was investigated and were found to increase as a function of SSA loading. The most promising membrane was then formed into a composite with either silica nanoparticles containing poly (2-acrylamido-2-methyl-1-propanesulfonic acid) (PAMPS-Si) or poly (styrene sulfonic acid) (PSSA-Si). PAMPS-Si and PSSA-Si were characterized by thermogravimetric analysis (TGA), transmission electron microscopy (TEM), and Fourier transform infrared spectroscopy (FTIR). The effects of nanoparticle loading and polymer shell on membrane properties were studied. Proton conductivity increased at higher nanoparticle loadings, and reached a maximum of 3.8–3.9 × 10−3 S/cm at 20% loading. The influence of polymer shell on membrane properties was not significantly observed.

An acid-base bifunctional zeolitic imidazolate framework catalyst (ZIF8-A61-SO3H) with amine and sulfonic acid groups was successfully prepared through simple two step post-synthetic modification: preparation of amine-functionalized ZIF-8 with amine contents of 61% (ZIF8-A61) by the ligand exchange of 2-mIM with 3-amino-1,2,4-triazole (Atz), followed by the sulfonic acid functionalization by the ring-opening reaction of 1,3-propanesultone with –NH2 groups in ZIF8-A61. Amine-functionalized ZIF8-A materials with difference amine contents (15%, 34%, and 61%, respectively) were also prepared by controlling the synthesis time. All obtained ZIF catalysts evaluated as a heterogeneous catalyst for one-pot deacetalization-Knoevenagel condensation tandem reaction. Compared with ZIF-8 and amine-functionalized ZIF-8 catalysts, ZIF8-A61-SO3H catalyst showed good catalytic performance with 100% conversion of the reactant and 98% selectivity of the final Knoevenagel product. An enhanced catalytic activity can be attributed to the co-existence of site-isolated acid-base groups on the ZIF8-A61-SO3H catalyst in close proximity. The heterogeneous nature of the catalytic system was confirmed by a hot-filtering test and the catalyst also exhibited reusable in the five repeated cycles. A plausible catalytic mechanism of deacetalization-Knoevenagel condensation reaction over ZIF8-A61-SO3H was also proposed.

The permeation of polar molecules (water and ammonia), non-polar dichloromethane and a mixture of ammonia and dichloromethane through graphene oxide (GO)/polymer matrix composite membranes was investigated. Results indicated that a hydrophilic poly(2-acrylamido -2 -methyl propane sulfonic acid) (PAMPS) based membrane had the highest permeability for water and ammonia due to the high hydrophilicity of the polymer matrix while a hydrophobic polyurethane (PU)-based membrane had the best permeation performance for dichloromethane and the worst performance for water and ammonia. Adding the GO to PU or PAMPS polymers increases the negative charge due to the negatively charged nature of GO caused by its oxygen-containing functional groups, which increases the amounts of absorbed water and ammonia due to the positive charge of the hydrogen atoms in these two molecules.

The characterization and enhanced oil recovery mechanisms of a nanosized polymeric cross-linked gel are presented herein. A negatively charged nanogel was synthesized using a typical free radical suspension polymerization process by employing 2-acrylamido 2-methyl propane sulfonic acid monomer. The synthesized nanogel showed a narrow size distribution with one peak pointing to a predominant homogeneous droplet size. The charged nanogels were also able to adsorb at the oil–water interfaces to reduce interfacial tension and stabilize oil-in-water emulsions, which ultimately improved the recovered oil from hydrocarbon reservoirs. In addition, a fixed concentration of negatively charged surfactant (sodium dodecyl sulfate or SDS) was combined with different concentrations of the nanogel. The effect of the nanogels combined with surfactant on sandstone core plugs was examined by running a series of core flooding experiments using multiple flow patterns. The results show that combining nanogel and SDS was able to reduce the interfacial tension to a value of 6 Nm/m. The core flooding experiments suggest the ability of the nanogel, both alone and combined with SDS, to improve the oil recovery by a factor of 15% after initial seawater flooding.

In this study, sulfonic acid-functionalized lignin-montmorillonite complex (LMT-SO3H) was prepared and employed as an efficient heterogeneous catalyst for the esterification of levulinic acid (LA) into n-butyl levulinate (BL). An intermediate pseudo-butyl levulinate (p-BL) was determined by distilled water treatment and nuclear magnetic resonance (NMR) analysis, and a possible mechanism for the esterification of LA is proposed. The effects of various process parameters were studied and the results showed that the LMT-SO3H catalyst had the excellent catalytic performance for esterification of the LA. Under optimum reaction conditions, the yield of BL was 99.3% and the conversion of LA was 99.8%. The LMT-SO3H catalyst exhibited strong acidic sites and high stability even after seven cycles of usage. Furthermore, esterification of the LA with various alcohols over the LMT-SO3H was further investigated.

We compared the performance of more than 70 solid acid catalysts with Bronsted acid function for the etherification of glycerol with isobutene under identical reaction conditions of 75 °C, 10 bar, 6 h and with an isobutene/glycerol molar ratio of 3/1. The catalysts were selected from a wide range of solid acid catalysts including ion exchange resins, zeolites, silica, and heteropolyacids, and their counterparts modified by simple treatments, with more than half of them being investigated for the first time for this reaction. For the modified commercial acid catalysts, the desired glycerol tertiary butyl ether (DTBGE and TTBGE) selectivity improved from 75 to 87 wt% upon partial cation exchange of the sulfonic acid protons in Amberlyst™ type ion exchange resins with Na+ cations; from 66 to 85 wt% by hydrothermal steam treatment of zeolite H-Y (SiO2/Al2O3 = 80); and from 75 to 80 wt% with partial La+-exchange of zeolite H-Beta (SiO2/Al2O3 = 300), all at high (90–100%) glycerol conversion. Impregnation of the heteropolyacids, tungstosilicic acid (TSA) and tungstophosphoric acid (TPA), on silica at a loading of 50 wt% provided a glycerol conversion of higher than 65 wt% and with a desired ether selectivity in the range of 62 to 76 wt%. In general, total ether selectivity increased with decreasing acid capacity for ion exchange resins, while the desired ether selectivity was enhanced with increasing acid strength for zeolites and supported heteropolyacids on mesoporous silica. Data present a detailed guideline for the selection of solid acid catalysts for the etherification of glycerol with isobutene.

There are numerous impurities in wet-process phosphoric acid, among which manganese is one of detrimental metallic impurities, and it causes striking negative effects on the industrial phosphoric acid production and downstream commodity. This article investigated the adsorption behavior of manganese from phosphoric acid employing Sinco-430 cationic ion-exchange resin. Resorting FT-IR and XPS characterizations, the adsorption mechanism was proved to be that manganese was combined with sulfonic acid group. Several crucial parameters such as temperature, phosphoric acid content and resin dose were studied to optimize adsorption efficiency. Through optimization, removal percentage and sorption capacity of manganese reached 53.12 wt%, 28.34 mg·g−1, respectively. Pseudo-2nd-order kinetic model simulated kinetics data best and the activation energy was evaluated as 6.34 kJ·mol−1 for the sorption reaction of manganese. In addition, the global adsorption rate was first controlled by film diffusion process and second determined by pore diffusion process. It was found that the resin could adsorb up to 50.24 mg·g−1 for manganese. Equilibrium studies showed that Toth adsorption isotherm model fitted best, followed by Temkin and Langmuir adsorption isotherm models. Thermodynamic analysis showed that manganese adsorption was an endothermic process with enhanced randomness and spontaneity.

Dual modified ionic cross-link polysulfone (PSF) polymer-based proton-conducting membrane is synthesized with an aim to provide low methanol permeability without sacrificing the proton conductivity for direct methanol fuel cell application. The modification of pristine PSF membrane with aniline and further cross-linking by sulfuric acid was confirmed by its detailed characterization. The modified membrane achieved a high proton conductivity of 0.072 Scm−1 (30 °C) and 0.178 Scm−1 (110 °C) in low humidity condition (40%). The membrane exhibits low methanol permeability (2.5 × 10−8 cm2s−1) with high selectivity (28.4 × 105 Scm3s−1). The higher diffusivity of hydronium ion (H3O+) with an increase in hydration level and temperature was studied by molecular dynamics simulation and well agrees with experimental results in terms of proton conductivity. The reduced electrostatic interactions between the sulfonic acid group and H3O+ ion were confirmed by the radial distribution function analysis. These interaction pushes the H3O+ ion that helps in the transfer of proton by increases their coordination with water. Moreover, the high interaction of amine group with H3O+ ion also contributes to the proton conductivity enhancement. The dual modified membrane achived maximum power density of 0.19 Wcm−2 at 45 mA cm−2 and was 42% higher as compared to aniline treated polysulfone (APSF) membrane.

A commercial perfluorinated sulfonic acid (PFSA) membrane, Nafion, shows outstanding conductivity under conditions of a fully humidified surrounding. Nevertheless, the use of Nafion membranes that operate only at low temperature (

This study fabricated N-(azobenzene-4-oxy-2-hydroxypropyl)-N-(alkyloxy-2-hydroxypropyl) aminopropyl sulfonic acid sodium salt (GnAZAS, n = 6, 8, and 12), a new photoresponsive anionic surfactant, through a simple, high-yield process involving ring-opening reactions of alkylglycidyl ether containing azobenzene and epoxide. The fabricated trans-GnAZAS can be transformed into 92.5% cis upon irradiation with 350 nm UV light, and was converted reversibly into 74% trans under irradiation with 450 nm visible light. Photoisomerization causes changes in the surface activity of surfactants. The critical micelle concentration (CMC) of the trans isomer of G12AZAS was 1.45 × 10−4 mol/L and the value of the 92.5% of cis isomer is 2.84 × 10−4 mol/L. Surface activity can be controlled by light in the range between the two CMC values, and the CMC difference for cis and trans forms of GnAZAS increased proportionately to the alkyl chain length. The minimum average area per molecule ( A m i n a / w ) of trans-G12AZAS is 1.14 nm2. This becomes 1.20 nm2 when converted to the cis form. The A m i n a / w is determined by structural differences between trans and cis isomers. In addition, this study examined the fabricated azobenzene surfactant in terms of emulsion stability, foaming power, and Turbiscan Stability Index (TSI), and compared it to commercialized surfactants LAE-9 and SLES-3.

To improve the photocatalytic performance of TiO2 photocatalysts, a new method, liquid phase plasma (LPP) method, was used to introduce nitrogen and iron oxide. Interstitial or substitutional nitrogen and Fe3+ iron nanoparticles were impregnated on the surface of TiO2 by LPP reaction without additional chemical reduction agent and the amount of iron of modified TiO2 photocatalysts was affected by the amount of initial precursor. The adsorption edge of modified TiO2 photocatalysts was shifted to the visible region in proportion to the amount of nitrogen and iron oxide, and the band gap energy was decreased, and the photocatalytic activity was confirmed by PL and EPR analysis. The photocatalytic activities of modified TiO2 photocatalysts were measured under UV and blue LED lamps and compared with pure TiO2 powder (P-25). The modified TiO2 exhibited better photocatalytic degradation performance than pure TiO2 under blue LED light conditions, but exhibited low degradation activity under UV LED light conditions. Through GC–MS analysis, it was found that the methylene blue was finally decomposed into an inorganic substance through intermediates such as benzene sulfonic acid and phenol by OH radicals. From these results, we found that the modified TiO2 photocatalysts can be easily prepared using the LPP method and can be used in the visible region.

Novel functionalized polysulfone with high local density of sulfonic acid groups, N,N-bis(sulfopropyl)aminyl-4-phenyl polysulfone or O,O′-bis(sulfopropyl)resorcinol-5-yl-4-phenyl polysulfone (PSF-X-C3H6SO3H, X = N or O) are synthesized. These polymers are synthesized by bromination of polysulfone followed by Suzuki cross-coupling reaction to graft the aminophenyl groups and the dimethoxyphenyl groups onto the polymeric backbone, followed by introduction of the sulfopropyl groups via sultone ring-opening reaction. In addition, the composite membrane of PSF-O-C3H6SO3H and PSF-N-C3H6SO3H is also synthesized for comparison. The maximum proton conductivity of composite PSF-O-C3H6SO3H and PSF-N-C3H6SO3H reaches 46.66 mS cm−1 at 95 °C and 90% RH, higher than PSF-O-C3H6SO3H (42.06 mS cm−1) and PSF-N-C3H6SO3H (38.76 mS cm−1). Meanwhile, the composite exhibits compromised water uptake and swelling ratio, and low methanol permeability. The excellent overall performance of the composite is attributed to phase-separation between the hydrophilic and the hydrophobic subphases, and the hydrogen-bonding network developed in the hydrophilic subphases.

Surfactant flooding is considered as one of the efficient chemical enhanced oil recovery techniques in recent decades as it has the potential ability to alter the wettability and reduce the interfacial tension of water-oil. Addition of surfactants has caused a dramatic decrease in the interfacial of water-oil. Thereby, the capillary number has increased and has caused to enhance oil mobilization in the porous media. In this paper, a cationic surfactant of Cetyl trimethyl ammonium bromide and an anionic surfactant of linear alkylbenzene sulfonic acid were used to consider their effect on the interfacial tension and oil recovery factor. According to the results of this study, the anionic surfactant of linear alkylbenzene sulfonic acid has the highest recovery factor of 70%, and cationic surfactant of Cetyl trimethyl ammonium bromide has the second-highest oil recovery factor of about 55%. Therefore, the addition of surfactants due to its beneficial impact on the interface adsorption between oil and water would be an essential point on the oil recovery enhancement as it can increase the oil recovery factor. Moreover, the critical micelle concentration value is about 300 ppm and 250 ppm for anionic and cationic surfactants respectively where the two crosslines meet each other and anionic has the highest interfacial tension rather than cationic which has caused to have more oil recovery factor.

Carbon nanotubes (CNTs) have been integrated into many electronic and energy devices due to their high conductivity and flexibility. Here, we report the discovery of poly (p-styrene-sulfonic acid) (PSS) as an efficient dispersant and stable dopant for CNTs. PSS showed an excellent dispersion performance; CNTs were partially dispersed by just stirring and well dispersed by sonication for only 3 min in PSS aqueous solution. PSS also showed an excellent doping performance; the as-filtrated CNT films, which had CNT bundles wrapped with a few nm-thick PSS layer, showed low sheet resistances of 115 and 49 Ω/sq at optical transmittances of 90% and 79%, respectively. Moreover, the CNT films showed long-term stability (>1000 h) and high-temperature stability (250 °C) in ambient air without any passivation layer. The simple dispersion and stable doping for CNTs is a promising way to achieve superior transparent conductive films for fundamental and industrial applications.

The present study aimed to produce a new, less toxic, and cost-effective polymer gel dosimeter using potassium salt of 2-acrylamido-2 methyl-propane sulfonic acid (AMPS) monomer. The new formulation was called PAKAG. The irradiation of PAKAG polymer gel dosimeter was performed using a 6 MV clinical linear accelerator, and its response was evaluated using magnetic resonance imaging. The obtained images were post-processed to produce related R2 maps. Afterward, the Dose-R2 calibration curves were obtained. Response dependence on the imaging temperature was examined. Furthermore, response stability over time was investigated. To investigate the radiological characteristics, the elemental composition, effective atomic number, electron density, and photon attenuation coefficient of PAKAG polymer gel dosimeter were calculated. A maximum sensitivity of 0.152±0.007 with the goodness of fit of R2=0.999 in a dynamic range of 0-6Gy at 12h post-irradiation time was found. Such as other polymer gel dosimeter, the response of PAKAG polymer gel dosimeter was dependent on post-irradiation time and imaging temperature. Finally, it was concluded that the PAKAG polymer gel dosimeter could be used as a less toxic and cost-effective polymer gel dosimeter.

Mesoporous Al2O3 obtained via a soft template method was used as a support for the immobilization of laccase from Trametes versicolor. Porous alumina is a very attractive engineering material extensively used in catalysis, adsorption and separation. The proposed route of synthesis of Al2O3 yielded a material with high well developed parameters of the porous structure and thermal, and kinetic stability. The next stage involved typical adsorption immobilization of laccase at different pH (3–6). The support and prepared biocatalytic system were comprehensively analyzed with respect to morphology, porosity, electrokinetic and thermal stability, and characteristic functional groups. Furthermore, the oxidation reaction of sulfonic acid was used as a model reaction to evaluate the catalytic activity of obtained biocatalyst. Based on this reaction, the influence of pH and temperature on catalytic activity was determined, in addition to the system’s storage stability and reusability. The biocatalytic system exhibits catalytic activity from 40% up to 100% in the analyzed pH range 3–6 and in the temperature range 30–70 °C. Additionally, laccase immobilized onto Al2O3 retains approximately 65% of its initial activity after 30 days of storage, and around 60% after 10 reaction cycles. A suggested mechanism of laccase immobilization was also proposed.

A new amphoteric membrane was prepared by blending long-side-chain sulfonated poly(2,6-dimethyl-1,4-phenylene oxide) (S-L-PPO) and polybenzimidazole (PBI) for vanadium redox flow battery (VRFB) application. An acid–base pair structure formed between the imidazole of PBI and sulfonic acid of S-L-PPO resulted in lowered swelling ratio. It favors to reduce the vanadium permeation. While, the increased sulfonic acid concentration ensured that proton conductivity was still at a high level. As a result, a better balance between the vanadium ion permeation (6.1 × 10−9 cm2·s−1) and proton conductivity (50.8 mS·cm−1) in the S-L-PPO/PBI-10% membrane was achieved. The VRFB performance with S-L-PPO/PBI-10% membrane exhibited an EE of 82.7%, which was higher than those of pristine S-L-PPO (81.8%) and Nafion 212 (78.0%) at 120 mA·cm−2. In addition, the S-L-PPO/PBI-10% membrane had a much longer self-discharge duration time (142 h) than that of Nafion 212 (23 h). Open Science Identity