Search Results (787)

This study investigates the thermal stability and microstructural evolution of the solid electrolyte medium used in DLyte^® dry electropolishing and dry anodizing processes. Samples were thermally aged between 30 °C and 45 °C to simulate Joule heating during industrial operation. Visual and SEM analyses revealed shape deformation and microcrack formation at temperatures above 40 °C, potentially reducing particle packing efficiency and electrolyte performance. Particle size distribution shifted from bimodal to trimodal upon aging, with an overall size reduction of up to 39.5% due to dehydration effects, impacting ionic transport properties. Weight-loss measurements indicated a diffusion-limited dehydration mechanism, stabilizing at 15–16% mass loss. Fourier transform infrared analysis confirmed water removal while maintaining the essential sulfonic acid groups responsible for ionic conductivity. In dry anodizing tests on titanium, aged electrolytes enhanced process efficiency, producing TiO₂ films with improved optical properties—color and brightness—while preserving thickness and uniformity (~70 nm). The results highlight the need to carefully control thermal exposure to maintain electrolyte integrity and ensure consistent process performance. Full article

Aqueous organic redox flow batteries (AORFBs) represent an advancing class of electrochemical energy storage systems showing considerable promise for large-scale grid integration due to their unique aqueous organic chemistry. However, the use of small-molecule active materials in AORFBs is significantly limited by the issue of stability and crossover. To address these challenges, we designed a high-water-solubility polymer cathode material, P-T-S, which features a polyvinylimidazole backbone functionalized with 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) and sulfonate groups. P-T-S exhibits a solubility of 34 Ah L⁻¹ in water and 31 Ah L⁻¹ in 1.0 M NaCl aqueous solution (NaCl_aq). When paired with methyl viologen to assemble a pH-neutral AORFB with a theoretical capacity of 15 Ah L⁻¹, the system exhibits a material utilization rate of 92.0%, an average capacity retention rate of 99.74% per cycle (99.74% per hour), and an average Coulombic efficiency of 98.69% over 300 consecutive cycles at 30 mA cm⁻². This work provides a new design strategy for polymer materials for high-performance AORFBs. Full article

The contamination of drinking water by per- and polyfluoroalkyl substances (PFASs) presents a global concern due to their extreme persistence, driven by strong C–F bonds. This study investigated the potential of graphene as a filtration material for PFAS removal, focusing on six key compounds regulated by the U.S. EPA: PFOA, PFNA, GenX, PFBS, PFOS, and PFHxS. Using molecular simulations, adsorption energy, diffusion coefficients, and PFAS-to-graphene distances were analyzed. The results showed that adsorption strength increased with molecular weight; PFOS (500 g/mol) exhibited the strongest adsorption (−171 kcal/mol). Compounds with sulfonic acid head groups (e.g., PFOS) had stronger interactions than those with carboxylate groups (e.g., PFNA), highlighting the importance of head group chemistry. Shorter graphene-to-PFAS distances also aligned with higher adsorption energies. PFOS, for example, had the shortest distance at 8.23 Å (head) and 6.15 Å (tail) from graphene. Diffusion coefficients decreased with increasing molecular weight and carbon chain length, with lower molecules like PFBS (four carbon atoms) diffusing more rapidly than heavier ones like PFOS and PFNA. Interestingly, graphene enhanced PFAS mobility in water, likely by disrupting the water structure and lowering intermolecular resistance. These results highlight graphene’s promise as a high-performance material for PFAS removal and future water purification technologies. Full article

Per- and polyfluoroalkyl substances (PFASs) have gained significant attention due to their widespread distribution in the environment and potential adverse health effects. While ingestion, especially through contaminated drinking water, is considered the primary route of human exposure, recent research suggests that other pathways, such as inhalation and dermal absorption, also play a significant role. This review provides a concise overview of the toxicological impacts of both legacy and emerging PFASs, such as GenX and perfluorobutane sulfonic acid (PFBS), with a particular focus on their effects on the liver, kidneys, and immune and nervous systems, based on findings from recent in vivo, in vitro, and epidemiological studies. Despite the transition to PFAS alternatives, much of the existing toxicity data focus on a few legacy compounds, such as perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS), which have been linked to adverse immune outcomes, particularly in children. However, evidence for carcinogenic risk remains limited to populations with extremely high exposure levels, and data on neurodevelopmental effects remain underexplored. While epidemiological and experimental animal studies supported these findings, significant knowledge gaps persist, especially regarding emerging PFASs. Therefore, this review examines the visceral, neural, and immunotoxicity data for emerging PFASs and mixtures from recent studies. Given the known risks from well-studied PFASs, a precautionary principle should be adopted to mitigate human health risks posed by this large and diverse group of chemicals. Full article

This study evaluated the effects of maternal supplementation with rumen-protected methionine (RPM), alone or combined with rumen-protected choline (RPC) and betaine (RPB), during the periconceptional and prepartum periods on reproductive outcomes and offspring performance in Chios ewes. One hundred synchronized ewes were assigned to three groups—control (no supplementation), M (5.50 g RPM/day), and MCB (3.50 g RPM, 1.60 g RPC, 0.49 g RPB/day)—from day −14 to +14 relative to mating. Blood was collected on days −14, 0, and +14 for ABTS (2,2′-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid), ferric-reducing ability (FRAP), and malondialdehyde (MDA), on days 18 and 21 for progesterone, and on day 26 for pregnancy-associated glycoprotein (PAG) detection. Thirty days before and up to lambing, the ewes were further divided into C-C, C-M, C-MCB, M-M, M-C, MCB-MCB, and MCB-C subgroups. Embryonic loss did not differ between groups. FRAP was higher (p < 0.001) in MCB ewes, and ABTS was lower (p < 0.05) in M ewes, in the periconceptional period. Offspring in the C-M, C-MCB, M-M, M-C, and MCB-MCB groups had higher birth weights (p < 0.01), along with increased MDA levels (p < 0.05). The results suggest that maternal methyl donor supplementation during early and/or late gestation enhances antioxidant status, supports embryonic development, and increases birth weight. Full article

The recovery and abatement of volatile organic compounds (VOCs) have received increasing attention due to their significant environmental and health impacts. Supported sulfonic acid materials have shown great potential in converting aromatic VOCs into their non-volatile derivatives through reactive adsorption. However, the anchoring state of sulfonic acid groups, which is closely related to the properties of the support, greatly affects their performance. In this study, two supported sulfonic acid materials, SZO and SMO, were prepared by treating ZrO₂ and MgO with chlorosulfonic acid, respectively, to investigate the influence of the support properties on the anchoring state of sulfonic acid groups and their reactive adsorption performance for o-xylene. The supports, adsorbents, and adsorption products were extensively characterized, and the reactivity of SZO and SMO towards o-xylene was systematically compared. The results showed that sulfonic acid groups are anchored on the ZrO₂ surface through covalent bonding, forming positively charged sulfonic acid sites ([O_1.5Zr-O]^δ−-SO3H^δ+) with a loading of 3.6 mmol/g. As a result, SZO exhibited excellent removal efficiency (≥91.3%) and high breakthrough adsorption capacity (ranging from 38.59 to 82.07 mg/g) for o-xylene in the temperature range of 130 –150 °C. In contrast, sulfonic acid groups are anchored on the MgO surface via ion-paired bonding, leading to the formation of negatively charged sulfonic acid sites ([O_0.5Mg]⁺:OSO₃H⁻), which prevents their participation in the electrophilic sulfonation reaction with o-xylene molecules. This work provides new insights into tuning and enhancing the performance of supported sulfonic acid materials for the resource-oriented treatment of aromatic VOCs. Full article

Objective: This study aimed to evaluate the in vitro efficacy of silver nanoparticles (AgNPs) synthesized by bioreduction using lemongrass (Cymbopogon citratus) essential oil against multidrug-resistant (MDR) bacteria isolated from an Intensive Care Unit (ICU). Methods: The essential oil was extracted and characterized by gas chromatography–mass spectrometry (GC-MS). Antioxidant activity was assessed using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay, the 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assay, and total phenolic content. AgNPs (3 mM and 6 mM silver nitrate) were characterized by UV-Vis spectroscopy, dynamic light scattering (DLS), zeta potential, transmission electron microscopy (TEM), and Fourier-transform infrared (FTIR) spectroscopy. Bacterial isolates were obtained from ICU surfaces and personal protective equipment (PPE). Results: The essential oil presented citral A, citral B, and β-myrcene as major components (97.5% of identified compounds). AgNPs at 3 mM showed smaller size (87 nm), lower Polydispersity Index (0.14), and higher colloidal stability (−23 mV). The 6 mM formulation (147 nm; PDI 0.91; −10 mV) was more effective against a strain of Enterococcus spp. resistant to all antibiotics tested. FTIR analysis indicated the presence of O–H, C=O, and C–O groups involved in nanoparticle stabilization. Discussion: The higher antimicrobial efficacy of the 6 mM formulation was attributed to the greater availability of active AgNPs. Conclusions: The green synthesis of AgNPs using C. citratus essential oil proved effective against MDR bacteria and represents a sustainable and promising alternative for microbiological control in healthcare environments. Full article

The inherent hydrophobic nature of PVDF material renders it challenging to establish a stable aqueous hydration layer, thereby limiting its suitability as a substrate for the preparation of nanofiltration (NF) membranes. In this study, we developed a novel modification approach that effectively enhances the hydrophilicity of PVDF substrates through the incorporation of sulfonic acid-doped polyaniline (SPANI) and hyperbranched polyester (HPE) into the PVDF casting solution, followed by cross-linking with trimesoyl chloride (TMC). The introduction of SPANI and HPE, which contain reactive polar amino and hydroxyl groups, improved the hydrophilicity of the substrate, while the subsequent cross-linking with TMC effectively anchored these components within the substrate through the covalent linking between TMC and the reactive sites. Additionally, the hydrolysis of TMC yielded non-reactive carboxyl groups, which further enhanced the hydrophilicity of the substrate. As a result, the modified PVDF substrate exhibited improved hydrophilicity, facilitating the construction of an intact polyamide layer. In addition, the fabricated TFC NF membrane demonstrated excellent performance in the advanced treatment of tap water, achieving a total dissolved solid removal rate of 57.9% and a total organic carbon removal rate of 85.3%. This work provides a facile and effective route to modify PVDF substrates for NF membrane fabrication. Full article

Films of functionalised multiwalled carbon nanotubes (MWCNTs) were fabricated as interlayers (interfacial layers between the cathode and separator) in a lithium–sulfur battery (LSB). Phenylsulfonate functionalisation of commercial MWCNTs was achieved via diazotisation to attach lithium phenylsulfonate groups and was characterised by IR and XPS spectroscopies. SEM-EDX showed sulfur and oxygen colocations due to the sulfonate groups on the interlayer surface. However, CHNS elemental microstudies showed a low degree of functionalisation. Without an interlayer, the LSB produced stable cycling at a capacity of 600 mA h g⁻¹_sulfur at 0.05 C for 40 cycles. Using an unfunctionalised interlayer as a control gave a capacity of 1400 mA h g⁻¹_sulfur for the first cycle but rapidly decayed to the same 600 mA h g⁻¹_sulfur at the 40th cycle at 0.05 C, suggesting a high degree of polysulfide shuttling. Adding a lithium phenylsulfonated interlayer gave an initial capacity increase to 1100 mA h g⁻¹_sulfur that lowered to 800 mA h g⁻¹_sulfur at 0.05 C by the 40th cycle, showing an increase in charge storage (33%) relative to the other cells. This performance increase has been attributed to lessened polysulfide shuttling due to repulsion by the phenylsulfonate groups, increased conductivity at the separator-cathode interface and an increase in surface area. Full article

The deep defluorination of water remains a significant environmental challenge. In this work, aluminum was loaded onto the bifunctional resin S957 containing a phosphoric-sulfonic acid difunctional group for efficient fluoride removal. Al-S957 demonstrated excellent fluoride removal performance across a broad pH range. When anions and organics coexisted, Al-S957 exhibited significantly better fluoride adsorption performance compared to aluminum-loaded monofunctional resins. The adsorption followed an endothermic chemisorption process on a monolayer surface. FTIR and XPS analyses further revealed that fluoride removal relied on a ligand exchange mechanism. Column adsorption conducted over five cycles highlighted the strong practical potential of Al-S957. The results suggested that Al-S957 exhibits significant potential for practical applications. Full article

This study investigates the potential of sulfuric acid modified wheat straw, polysaccharide-rich agricultural byproduct, as a low-cost adsorbent for the selective adsorption of Au(III) ions from aqueous solutions. The wheat straw was treated with concentrated sulfuric acid to enhance its surface properties and functional groups, particularly sulfonic and oxygen-containing functional groups. Adsorption experiments were performed under various conditions, including acid concentrations ranging from 1.0 to 3.0 mol/L, contact times from 1 to 6 h, and initial Au(III) concentrations of 60.36, 90.0, and 150.0 mg/L. The highest adsorption efficiency, 99.0%, was achieved at an acid concentration of 1.0 mol/L. Furthermore, it was determined that an increase in the initial Au(III) concentration from 60.36 mg/L to 150.0 mg/L resulted in a 4.5 times increase in maximum adsorption capacity under optimal conditions. Kinetic modeling revealed that the adsorption process followed pseudo-second order kinetics, suggesting chemisorption as the rate-limiting step. Characterization techniques such as SEM/EDS, XRD, BET and XPS confirmed structural modification, surface sulfonating, and the successful adsorption and reduction of Au(III) to elemental gold (Au⁰) on the modified straw surface. This work demonstrates that modified wheat straw is a promising, effective, and low cost for the recovery of gold from low-concentration solutions and provides insight into the adsorption and reduction mechanisms at the molecular level. Full article

Neurodegenerative, neurodevelopmental, and psychiatric disorders, as well as epilepsy, affect millions of people. Due to their impact on patients’ quality of life, they represent a major health issue. Natural compounds are arising as new treatments for these diseases. Particularly, glucosinolates (GLS) are secondary metabolites found in Cruciferae family plants. Their basic structure consists of a glucose unit linked to a thiohydroximate-O-sulfonate group and an aliphatic, aralkyl, or indolyl side chain, depending on their precursor amino acid. Specifically, aliphatic GLS derive from methionine, aromatic ones from phenylalanine, and indolic ones from tryptophan. Myrosinase (thioglucoside glucohydrolase) is the crucial enzyme for GLS degradation, leading to the production of isothiocyanates (ITCs). ITCs attracted considerable scientific interest for their protective effects against various diseases, thanks to their antioxidant, anti-inflammatory, and neuroprotective properties. Here, we collected the latest evidence regarding ITC effects in neurodegenerative, neurodevelopmental, and psychiatric disorders, including preclinical and clinical studies published in the last decade. These studies evidenced ITCs’ neuroprotective effects, exerted mainly through antioxidant and anti-inflammatory mechanisms. Thus, ITCs’ integration, also through the diet, may represent a safe and efficacious strategy to improve health and limit the risk of neurological and psychiatric disorders. However, new large-scale trials are needed to determine their therapeutic potential, particularly for diseases with no clinical evidence. Full article

Proton exchange membranes are widely used in environmentally friendly applications such as fuel cells and electrochemical hydrogen compression. In these applications, an ideal proton exchange membrane should have both excellent proton conductivity and mechanical strength. Polymer proton exchange membranes, such as sulfonated poly(ether ether ketone) (SPEEK) membranes with high ion exchange capacity, can lead to higher proton conductivity. However, the ionic groups may reduce the interaction between polymer segments, lower the membrane’s mechanical strength, and even cause it to dissolve in water as the temperature exceeds 55 °C. The porous graphitic C₃N₄ (Pg–C₃N₄) nanosheet is an important two–dimensional polymeric carbon–based material and has a high content of –NH₂ and –NH– groups, which can interact with the sulfonic acid groups in the sulfonated SPEEK polymer, form a more continuous proton transfer channel, and inhibit the movement of the polymer segment, leading to higher proton conductivity and mechanical strength. In this study, we found that a SPEEK membrane containing 3% Pg–C₃N₄ nanosheets achieves the optimized proton conductivity of 138 mS/cm (80 °C and 100% RH) and a mechanical strength of 74.1 MPa, improving both proton conductivity and mechanical strength by over 50% compared to the SPEEK membrane. Full article

Background/Objectives: Positron emission tomography (PET) and single-photon emission computed tomography (SPECT) are highly sensitive clinical imaging modalities, frequently employed in conjunction with magnetic resonance imaging (MRI) or computed tomography (CT) for diagnosing a wide range of disorders. Efficient and robust radiolabeling methods are needed to accommodate the increasing demand for PET and SPECT tracer development. Copper-mediated radiohalogenation (CMRH) reactions enable rapid late-stage preparation of radiolabeled arenes, yet synthetic challenges and radiolabeling precursors’ instability can limit the applications of CMRH approaches. Methods: A series of aryl-boronic acids were converted into their corresponding aryl-boronic acid 1,1,2,2-tetraethylethylene glycol esters [ArB(Epin)s] and aryl-boronic acid 1,1,2,2-tetrapropylethylene glycol esters [ArB(Ppin)s] as stable and versatile precursor building blocks for radiolabeling via CMRH. General protocols for the preparation of ¹⁸F-labeled and ¹²³I-labeled arenes utilizing CMRH of these substrates were developed and applied. The radiochemical conversions (RCC) were determined by radio-(U)HPLC. Results: Both ArB(Epin)s and ArB(Ppin)s-based radiolabeling precursors were prepared in a one-step synthesis with chemical yields of 49–99%. Radiolabeling of the aryl-boronic esters with fluorine-18 or iodine-123 via CMRH furnished the corresponding radiolabeled arenes with RCC of 7–99% and 10–99%, respectively. Notably, a radiohalogenated prosthetic group containing a vinyl sulfone motif was obtained with an activity yield (AY) of 18 ± 3%, and applied towards the preparation of two clinically relevant PET tracers. Conclusions: This approach enables the synthesis of stable radiolabeling precursors and thus provides increased versatility in the application of CMRH, thereby supporting the development of novel PET and SPECT radiotracers. Full article

The valorization of advanced biorefinery lignins remains a significant challenge, owing to the presence of residual carbohydrates. These lignin-associated carbohydrates hinder lignin purification, reduce its homogeneity, and complicate chemical modifications, ultimately limiting the efficient conversion of lignin into high-value products such as chemicals and materials. This study presents a protic ionic liquid-based lignin fractionation process developed using softwood biomass. Triethylammonium methane sulfonate ([N222H][OMS]) was used to fractionate Pinus sylvestris, yielding two distinct fractions: a low-molecular-weight lignin fraction (LF) and a high-molecular-weight lignin fraction (HF). The extracted fractions were comprehensively characterized using nuclear magnetic resonance (NMR) to quantify changes in interunit linkages (β-O-4, β-5, and β-β) and hydroxyl group distribution, whereas methanolysis gas chromatography/mass spectrometry (GC/MS) was used to quantify residual carbohydrates. The fractionation process achieved LF and HF yields of approximately 70.32% and 17.58%, respectively. Further analysis revealed that the HF contained 59.92 ± 2.12 mg/g carbohydrates, whereas the LF contained only 27.37 ± 1.13 mg/g. These findings underscore the effectiveness of the protic ionic liquid fractionation process in reducing carbohydrate impurities and enhancing lignin purity, paving the way for the more efficient utilization of lignin in value-added applications. Full article