Sulfonic Acid Research Articles

Spatiotemporal Proximity‐Enhanced Biocatalytic Cascades Within Metal–Organic Frameworks for Wearable and Theranostic Applications

AbstractEnzymatic catalysis, particularly multi‐enzyme cascade catalytic, is often limited by the spatial and temporal separation of enzymes and their signal substrates. Herein, a facile method for producing a spatiotemporal proximity‐enhanced biocatalytic cascade system is introduced by encasing enzymes within metal–organic frameworks (MOFs) that are modulated with sulfonic acid‐functionalized signal substrates. The modulated behavior relies on the sulfonic acid groups coordinated with Zn2+. As a proof of concept, by utilizing 2,2′‐Azinobis (3‐ethylbenzothiazoline‐6‐sulfonic acid ammonium salt) (ABTS), a widely‐used signal substrate for horseradish peroxidase, two‐enzyme/substrate, and three‐enzyme/substrate MOFs, which demonstrated a 7.4‐ and 10.2‐fold increase in biocatalytic efficiency over free systems are successfully synthesized. Incorporating the synthesized MOFs into homemade wearable patches and in vivo settings, noninvasive sweat glucose colorimetric detection and photoacoustic imaging‐guided photothermal tumor therapy are enabled, respectively. This advancement stems from the newly established coordinative bonds between Zn2+ centers and substrates' sulfonic acid groups, which negates the need for additional signal substrates, thereby not only enhancing but also streamlining bioapplication processes.

Nested cross-validation Gaussian process to model dimethylsulfide mesoscale variations in warm oligotrophic Mediterranean seawater

The study proposes an approach to elucidate spatiotemporal mesoscale variations of seawater Dimethylsulfide (DMS) concentrations, the largest natural source of atmospheric sulfur aerosol, based on the Gaussian Process Regression (GPR) machine learning model. Presently, the GPR was trained and evaluated by nested cross-validation across the warm-oligotrophic Mediterranean Sea, a climate hot spot region, leveraging the high-resolution satellite measurements and Mediterranean physical reanalysis together with in-situ DMS observations. The end product is daily gridded fields with a spatial resolution of 0.083° × 0.083° (~9 km) that spans 23 years (1998–2020). Extensive observations of atmospheric methanesulfonic acid (MSA), a typical biogenic secondary aerosol component from DMS oxidation, are consistent with the parameterized high-resolution estimates of sea-to-air DMS flux (FDMS). This represents substantial progress over existing coarse-resolution DMS global maps which do not accurately depict the seasonal patterns of MSA in the Mediterranean atmospheric boundary layer.

Single-molecule profiling of per- and polyfluoroalkyl substances by cyclodextrin mediated host-guest interactions within a biological nanopore.

Biological nanopores are increasingly used in molecular sensing due to their single-molecule sensitivity. The detection of per- and polyfluoroalkyl substances (PFAS) like perfluorooctanoic acid and perfluorooctane sulfonic acid is critical due to their environmental prevalence and toxicity. Here, we investigate selective interactions between PFAS and four cyclodextrin (CD) variants (α-, β-, γ-, and 2-hydroxypropyl-γ-CD) within an α-hemolysin nanopore. We demonstrate that PFAS molecules can be electrochemically sensed by interacting with a γ-CD in a nanopore. Using HP-γ-CDs with increased steric resistance, we can identify homologs of the perfluoroalkyl carboxylic acid and the perfluoroalkyl sulfonic acid families and detect common PFAS in drinking water at 0.4 to 2 parts per million levels, which are further lowered to 400 parts per trillion by sample preconcentration. Molecular dynamics simulations reveal the underlying chemical mechanism of PFAS-CD interactions. These insights pave the way toward nanopore-based in situ detection with promises in environmental protection against PFAS pollution.

An integrated approach to evaluating water contaminants and evaporation in agricultural water distribution systems

This study presents an innovative approach for assessing water quality in agricultural irrigation networks, integrating stable isotope analysis, in vivo zebrafish screening, and comprehensive chemical profiling to investigate the occurrence, transformation, and potential toxicity of organic contaminants. Stable isotope analysis was used to measure evaporation as a proxy for water residence time in the canal, while liquid chromatography-high resolution mass spectrometry (LC-HRMS) identified a range of organic compounds in water samples collected from both the irrigation canal and its source river. Results indicated a reduction in contaminant levels in the canal compared to the river, with the most significant evaporation and concentration changes occurring at a holding reservoir, suggesting that managing residence time could help reduce water loss in arid irrigation networks. The data also highlighted how evaporation, particularly during the dry, hot season, influences contaminant dynamics. Hierarchical clustering of LC-HRMS results showed notable differences between the chemical profiles of canal and river samples, indicating that irrigation systems may contribute to the degradation or removal of certain compounds. Over 60 % of detected compounds were naturally derived, with anthropogenic contaminants like pesticides and personal care products further highlighting human impacts. Priority contaminants, including DEET and 2-naphthalene sulfonic acid, likely originated from urban activities upstream. Initial screening using zebrafish embryos showed bioactivity across sites, confirming the presence of contaminants needing further examination. Correlation analysis linked natural compounds to evaporation rates, suggesting that flora and fauna play significant roles in the chemical makeup of canal water. Overall, this approach provides a comprehensive framework for monitoring irrigation water, offering insights into contaminant behavior and supporting the development of standardized methods for assessing chemical fate and ecological risks in agricultural irrigation systems.

One-Pot, Solvent Free Synthesis of 2,5-Furandicarboxylic Acid from Deep Eutectic Mixtures of Sugars as Mediated by Bifunctional Catalyst.

Currently one-pot conversion of sugars to 2,5-furandicarboxylic acid (FDCA) is of significant interest due to the attainability of sugars as a feedstock and the enormous potential of FDCA as a bioplastic monomer. However, it remains challenging to construct efficient catalysts for this process. In this study, Co3O4 species were anchored to a sulfonated covalent organic framework thus affording a bifunctional catalyst (Co3O4@COF-SO3H). The sulfonic acid sites dehydrate sugars to 5-hydroxymethylfurfural (HMF), which is next oxidized to FDCA as catalyzed by the Co3O4 species. Such a process was applied in the conversion of various binary and ternary deep eutectic mixtures involving choline chloride and sugars without additional solvent. The maximum FDCA yield of 84 % was obtained using glucose-fructose eutectic mixture as the substrates. Moreover, the catalyst was recyclable and stable under the applied reaction conditions. Our process eliminates the employment of organic solvents and expensive noble metal catalysts, resulting in green and economic biomass conversions.

Electrically Controlled Smart Window for Seasonally Adaptive Thermal Management in Buildings.

Smart windows offer a sustainable solution for energy-efficient buildings by adapting to various weather conditions. However, the challenge lies in achieving precise control over specific sunlight bands to effectively respond to complex weather changes and individual needs. Herein, a novel electrochromic smart window fabricated by integrating a self-assembled cellulose nanocrystals (CNCs) layer with an electrochromic poly(3,4-ethylenedioxythiophene):poly(styrene sulfonic acid) (PEDOT:PSS) layer is reported, which exhibits high near-infrared transmittance, low solar reflectivity (26%), and infrared emissivity (20%) in winter, and low near-infrared transmittance, high solar reflectivity (91%), and infrared emissivity (≈94%) in summer. Interestingly, the material offers dynamic temperature control based on its photothermal properties, maintaining the internal temperature of buildings within a comfortable range of 20-25 °C from morning to night, particularly in winter with significant daily temperature fluctuations. Simulations show that the CNC-PED device demonstrates excellent energy-saving and CO2 emission reduction capacities across various global climate zones. This study presents a feasible pathway for constructing season-adaptive smart windows, making them suitable for energy-efficient buildings.

Photocatalytic degradation of organic dyes under sunlight using a mononuclear Zn complex-embedded-functionalized porous material.

In this study, mesoporous materials (MCM-41 and MCM-48) were synthesized and functionalized with an acid group through a post-synthetic modification method. A mononuclear Zn complex [Zn(dmp)Cl2] (dmp = neocuprine) was also prepared and incorporated into a functionalized mesoporous material. Extensive characterization of the material married was carried out using techniques such as X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) analysis, scanning electron microscopy (SEM), nuclear magnetic resonance (NMR), and Fourier-transform infrared spectroscopy (FT-IR) to evaluate the characteristics of modified materials. The characterization results revealed that the post-synthetic modification did not alter the phase purity, crystallinity, or morphology of the mesoporous materials while confirming the successful grafting of the desired sulphonic acid functionality and Zn complex. The Zn complex-grafted-functionalized mesoporous materials were then assessed for their photo-degradation using methylene blue (MB) and rhodamine B (RB). The results demonstrated exceptional photo-degradation efficiency of the modified materials under sunlight. Within 15min, 10mg/ml of dye concentration, and adsorbent dosage 0.15mg/ml and 0.1mg/ml, degradation efficiencies of 99% and 92%, were achieved for MB using M-48-S-Zn1 and M-41-S-Zn1, respectively. Similarly, 91% and 78% degradation rates were achieved within 30min for RB using the same materials. The modified mesoporous materials exhibited a remarkable degradation performance even in challenging environments, including highly acidic, basic, and salt-concentrated conditions. This highlights the versatility and robustness of the modified materials in different environmental scenarios.

Endoplasmic Reticular Stress and Pathogenesis of Experimental Colitis: Mechanism of Action of 5-Amino Salicylic Acid.

Inflammatory bowel diseases which are characterized by endoplasmic reticulum (ER) stress and activation of the unfolded protein response (UPR) signaling pathway, are commonly treated with 5-amino salicylic acid (5-ASA). The objective of this study was to investigate the role of 5-amino salicylic acid in the UPR-signaling pathway in experimental colitis. Colitis was induced in male Sprague-Dawley rats by intrarectal instillation of trinitrobenzene sulfonic acid. Animals received 5-amino salicylic acid (100 mg/kg body weight) two hours before the induction of colitis and repeated daily until day 7. The animals were sacrificed on day 7 and tissues were collected for analysis. The expression of protein kinase R (PKR)-like endoplasmic reticulum (ER) kinase (PERK), a mediator of UPR-signaling increased significantly (p < 0.05), while inositol requiring enzyme type-1 (IRE1) and the CCAAT/enhancer-binding homologous protein (CHOP) remained unaltered in the inflamed colon. The expression of glucose regulated protein-78, activator of transcription factor-4 and phosphorylated eukaryotic initiation factor-2α (eIF2αP) increased (p < 0.05) in the inflamed colon. However, the levels of eIF2α protein and mRNA expression remained unchanged. Myeloperoxidase activity, colon weight and infiltration of inflammatory cells increased significantly (p < 0.05) in the submucosa whereas the body weight decreased. These changes were significantly inhibited by 5-amino salicylate treatment. These findings suggest that the anti-inflammatory properties of 5-amino salicylic acid are mediated through the inhibition of the PERK signaling pathway.

Application of coniferous bark as sorbent material for per- and polyfluoroalkyl substances – A case study in Sweden

Per- and polyfluoroalkyl substances (PFAS) are anthropogenic contaminants commonly found in drainage water from waste management facilities. Within the European Union, these facilities either treat the water locally or transfer it to wastewater treatment plants to reduce harmful emissions. However, PFAS are a broad class of compounds with varying physicochemical properties, leading to different removal efficiencies for adsorbents. Activated carbon and ion exchange resins are effective but costly, and they can become saturated with other contaminants. Therefore, this study aims to explore inexpensive, abundant alternatives for reducing PFAS concentrations in the environment. In Sweden, bark is a by-product of forestry activities, primarily used as fuel in heat and power plants. This study evaluates the ability of pine and spruce bark to remove PFAS from contaminated drainage water. Initial laboratory experiments employed liquid-to-solid ratios of 10 and 20 to assess the performance of both materials. Results indicated that pine bark exhibited better removal efficiencies, particularly when a layered column with pine bark followed by spruce bark was utilized. The overall removal efficiencies for short-chain PFAS (perfluorinated carbons: PFCA C3–C6 and PFSA C4–C5) and long-chain PFAS (PFCA > C7 and PFSA > C6) were below 20%, except for perfluorooctane sulfonic acid (PFOS), which showed reductions of 40%–80%. The pH of the treated water decreased from 7 to 4 (pine bark) and 5 (spruce bark) after treatment. In a larger-scale trial, a combination of 50% pine bark and 50% spruce bark was tested, achieving similar reductions for PFOS. Although the removal efficiencies were insufficient for exclusive treatment, these materials may be useful in specific applications targeting long-chain PFAS or in conjunction with other treatment methods.

Atmospheric implications of hydrogen bonding between methanesulfonic acid and 12 kinds of N-containing compounds

The hydrogen bonding interactions between methanesulfonic acid (MSA) and NHx compounds, such as ammonia (A), alkylamines (aNHx), and cyclic amino compounds (cNHx), were investigated using density functional theory, atoms in molecules, localized molecular orbitals-based energy decomposition analysis, and atmospheric clusters dynamic code methods. The results revealed that these dimers exhibit hydrogen bonds by SOH⋯N interactions. MSA–cNHx dimers showed higher binding energies compared to MSA–aNHx/A dimers. Topological analysis using AIM confirmed the presence of hydrogen bonding in these dimers by ρ(r) and ∇2ρ(r). The results of IRI indicate that there are different strength types of hydrogen bonding interactions in these dimers. LMO–EDA highlighted electrostatic interactions as the main attractive force, particularly in MSA–cNHx dimers. ACDC results showed a low evaporation rate for MSA–cNHx dimers compared to others. These findings suggest that MSA plays a crucial role in NPF events, and MSA–cNHx clusters could potentially act as nucleation nuclei in the atmosphere.

A Prospective Analysis of Per- and Polyfluoroalkyl Substances from Early Pregnancy to Delivery in the Atlanta African American Maternal-Child Cohort.

Longitudinal trends in per- and polyfluoroalkyl substances (PFAS) serum concentrations across pregnancy have not been thoroughly examined, despite evidence linking prenatal PFAS exposures with adverse birth outcomes. We sought to characterize longitudinal PFAS concentrations across pregnancy and to examine the maternal-fetal transfer ratio among participants in a study of risk and protective factors for adverse birth outcomes among African Americans. In the Atlanta African American Maternal-Child cohort (2014-2020), we quantified serum concentrations of four PFAS in 376 participants and an additional eight PFAS in a subset of 301 participants during early (8-14 weeks gestation) and late pregnancy (24-30 weeks gestation). Among these, PFAS concentrations were also measured among 199 newborns with available dried blood spot (DBS) samples. We characterized the patterns, variability, and associations in PFAS concentrations at different time points across pregnancy using intraclass correlation coefficients (ICCs), maternal-newborn pairs transfer ratios, linear mixed effect models, and multivariable linear regression, adjusting for socioeconomic and prenatal predictors. Perfluorohexane sulfonic acid (PFHxS), perfluorooctane sulfonic acid (PFOS), perfluorooctanoic acid (PFOA), and perfluorononanoic acid (PFNA) were detected in of maternal samples, with PFHxS and PFOS having the highest median concentrations. We observed high variability in PFAS concentrations across pregnancy time points (). All median PFAS concentrations increased from early to late pregnancy, except for PFOA and N-methyl perfluorooctane sulfonamido acetic acid (NMFOSAA), which decreased [paired -test for all PFAS except for PFOA and perfluorobutane sulfonic acid (PFBS)]. Prenatal serum PFAS were weakly to moderately correlated with newborn DBS PFAS ( ). The median maternal-fetal PFAS transfer ratio was lower for PFAS with longer carbon chains. After adjusting for socioeconomic and prenatal predictors, in linear mixed effect models, the adjusted mean PFAS concentrations significantly increased during pregnancy, except for PFOA. In multivariable linear regression, PFAS concentrations in early pregnancy significantly predicted the PFAS concentrations in late pregnancy and in newborns. We found that the concentrations of most PFAS increased during pregnancy, and the magnitude of variability differed by individual PFAS. Future studies are needed to understand the influence of within-person PFAS variability during and after pregnancy on birth outcomes. https://doi.org/10.1289/EHP14334.

Atomically dispersed Fe boosting elimination performance of g-C3N4 towards refractory sulfonic azo compounds via catalyst-contaminant interaction

Herein, an oxygen-doped porous g-C3N4 photocatalyst modified with atomically dispersed Fe (Fe1/OPCN) is successfully prepared and exhibits significant superiority in removing refractory sulfonic azo contaminants from water via catalyst-contaminant interaction. The elimination performance of Fe1/OPCN towards acid red 9, acid red 13 and amaranth containing similar azonaphthalene structure and increasing sulfonic acid groups increases gradually. The amaranth degradation rate of Fe1/OPCN is 17.7 and 6.1 times as that of homogeneous Fenton and OPCN, respectively. In addition, Fe1/OPCN also has more outstanding removal activities towards other contaminants with sulfonic acid and azo groups alone. The considerable enhancement for removing sulfonic azo contaminants of Fe1/OPCN is mainly ascribed to the following aspects: (1) The modified Fe could enhance the adsorption towards sulfonic azo compounds to accelerate the mass transfer, act as e- acceptor to promote interfacial charge separation, and trigger the self-Fenton reaction to convert in-situ generated H2O2 into •OH. (2) Fe(Ⅲ) could coordinate with —N=N— to form d-π conjugation, which could attract e- transfer to attack —N=N— bond. Meanwhile, the inhibited charge recombination could release more free h+ to oxidize sulfonic acid groups into SO4-•. (3) Under the cooperation of abundant multiple active species (•O2-, h+, e-, •OH, SO4-•) formed during the degradation reaction, sulfonic azo compounds could be completely mineralized into harmless small molecules (CO2, H2O, etc.) by means of —N=N— cleavage, hydroxyl substitution, and aromatic ring opening. This work offers a novel approach for effectively eliminating refractory sulfonic azo compounds from wastewater.

Biodegradable genipin cross-linked chitosan/pea protein isolate sponges for effective adsorption of methyl blue: Batch experiments and quantum chemical analysis

This study successfully prepared double crosslinked chitosan (CS) and pea protein isolate (PPI) composite sponges using genipin as a crosslinking agent and investigated their effectiveness as an adsorbent for methyl blue (MEB) in aqueous solutions. The composite sponges were characterized using scanning electron microscopy, Fourier transform infrared spectroscopy, Brunauer-Emmett-Teller measurement, swelling tests, gel fraction measurement, zeta potential, and X-ray diffraction. Additionally, the effects of genipin content, pea protein isolate content, sponge dosage, initial pH of the solution, adsorption time, dye concentration, and adsorption temperature on dye removal ability were studied. The results showed that at pH 3.0 and a dye concentration of 100 mg/L, the adsorption capacity of the sponge for methyl blue was found to be 351.6 mg/g. At 298 K and after 720 min, with a dye concentration of 700 mg/L, the maximum adsorption capacity of the sponge for methyl blue reached 959.3 mg/g. The adsorption process follows a pseudo-second-order kinetic model and a Langmuir isotherm. Theoretical analysis using density functional theory suggests that the adsorption of methyl blue by the composite sponge is attributed to the anionic sulfonic acid group of the dye. The composite sponge degraded 76.1 % after being buried in soil for 21 days. This study reveals the enormous potential of biodegradable chitosan-protein-based sponges in effectively removing methyl blue dye pollutants from wastewater.

Hydrocarbon-based composite membranes containing sulfonated Poly(arylene thioether sulfone)-grafted 2D crown ether framework coordinated with cerium ions for PEMFC applications

We propose a novel strategy to develop sulfonated poly(arylene ether sulfone) (SPAES) composite membranes that can simultaneously improve the physicochemical stability and proton conductivity of hydrocarbon-based membranes for PEMFC applications. This strategy involves the use of a sulfonated poly(arylene thioether sulfone)-grafted 2D crown ether framework coordinated with cerium3+ ions (SATS–C2O–Ce) as a promising filler material. SATS-C2O, a highly sulfonated polymer-grafted 2D framework containing crown ether holes in its skeletal structure, was prepared via self-condensation using halogenated phloroglucinol as a multifunctional building unit to form C2O, followed by condensation using SATS to graft the sulfonated polymer onto its edge. Ce3+ ions were directly coordinated within the crown ether holes of SATS-C2O via a simple doping process using aqueous Ce solution. The SPAES composite membranes containing SATS–C2O–Ce (SPAES/SATS–C2O–Ce) exhibited exceptional dimensional stability and mechanical toughness. The remarkable chemical stability of SPAES/SATS–C2O–Ce compared to that of pristine SPAES and SPAES/Ce (containing the same amount of Ce3+ ions but without SATS-C2O) was attributed to the well-dispersed state of Ce3+ ions within the SPAES matrix. Furthermore, the enhanced proton conductivity of SPAES/SATS–C2O–Ce surpassed those of pristine SPAES, SPAES/C2O, and SPAES/Ce by the formation of additional proton-conducting channels provided by the sulfonic acid groups of SATS–C2O–Ce, along with the improved water uptake capability of SPAES.

The effect of biochar in a specialty adsorbent on enhanced PFAS removal from surface water

An enhanced specialty adsorbent, referred to as biochar-based iron and perlite-integrated green environmental media (BIPGEM), was designed to simultaneously remove both long-chain PFAS mainly including perfluorooctanoic acid (PFOA) and Perfluorooctanesulfonic acid (PFOS) from surface water matrices. Batch-scale experiments using BIPGEM revealed that the removal efficiencies for PFOA and PFOS exceeded 98 % when treating a mixture of 3 short-chain PFAS, including perfluorobutanoic acid (PFBA), perfluorobutane sulfonic acid (PFBS), and hexafluoropropylene oxide dimer acid (GenX Chemicals). Additionally, a fixed-bed column study using BIPGEM revealed that the removal efficiencies of PFOA and PFOS were over 85 % within the first 12 h whereas the removal efficiency of PFBA was over 40 % at the fortieth hour. It was confirmed that the critical role of biochar in the removal of long-chain PFAS, particularly PFOA, can be attributed to the following factors: (1) the morphological structure and pore size of biochar restrict PFAS mobility, (2) the extensive specific surface area of biochar, with a positive charge (point of zero charge = 10.7) at the experimental condition, enhances the adsorption likelihood with the negatively charged hydrophilic heads of PFOA and PFOS, and (3) the presence of non-polar aromatic rings with high hydrophobicity in biochar facilitates the removal of PFAS through hydrophobic interactions with the functional groups of PFAS.

Highly flexible SCOF proton exchange membrane reinforced with PTFE to enhance fuel cell power density

Sulfonated covalent organic frameworks (SCOFs) facilitate rapid proton conduction through densely ordered sulfonic acid groups, however, the brittleness of COFs self-supporting membranes often makes potential difficulty in fuel cell assembly and limits their power density. Herein, a highly flexible SCOF proton exchange membrane is developed through in-situ growth of a continuous BD(SO3H)2-COF microphase within porous PTFE networks. The strong hydrogen bonding between PTFE and BD(SO3H)2-COF contributes to the defect-free morphology of the BD(SO3H)2/PTFE membrane. The reinforce of PTFE network makes the membrane extremely high flexibility, achieving an elongation at break of 124.4% even with a remarkably high SCOF mass proportion of 90 wt.% (BD(SO3H)2/PTFE-0.9). This allows the membrane to be folded repeatedly, even in dry state. The swelling ratio in water at 80 °C is effectively restricted to 8.6%, even with a high ion exchange capacity of 3.6 mmol g-1 and a water uptake of 68.2%. The densely ordered sulfonic acid groups in continuous BD(SO3H)2-COF microphase contribute to a high proton conductivity up to 249.2 mSꞏcm-1 at 80°C, approximately 1.5 folds that of Nafion 212. As a result, the BD(SO3H)2/PTFE-0.9 membrane achieves a fuel cell power density of 1195.3 mWꞏcm-2 at 80°C, along with a high open circuit voltage of 1.01 V, surpassing the-state-of-the-art COF-based proton exchange membranes. This work provides a novel strategy to fabricate COFs into flexible and size scalable membranes, enhancing the performance of fuel cells.

Mechanism of unactivated peroxymonosulfate-induced degradation of amino-G acid: Kinetics and transformation pathway

Amino-G acid (7-amino-1,3-naphthalenedisulfonic acid), a pollutant produced during textile preparation and in dyeing industries, is discarded in wastewater and causes ecological problems. In this study, amino-G acid (50.0 μM) could be completely removed by unactivated peroxymonosulfate (PMS) (1.0 mM) within 240 min, and the reaction kinetics exhibited strong pH dependence. A species-specific parallel reaction describes this pH dependence well, and the species-specific reaction rate constants of [amino-G acid]2− and [amino-G acid]− with HSO5− were calculated to be 0.0826 ± 0.0019 and 000122 ± 0.0027 M−1 s−1. The reactivity of the six naphthalene sulfonic acids and unactivated PMS varied according to the structure, and the amino group in naphthalene sulfonic acid, a typical electron-donating group, was more vulnerable to attack by unactivated PMS, which was further confirmed by the density functional theory results. The high-performance liquid chromatography coupled to mass spectrometry (HPLC-MS) spectral analysis results indicated that naphthalene sulfonic acid was first oxidized to hydroxylamine products and then further oxidized to nitroso compounds, which exhibited more ecological toxicity. However, as the reaction processing, the toxicity of the product gradually decreased. Our results provide new insights into the in-situ oxidation of unactivated PMS.

Exploring the role of SAP chemical composition in the internal curing of high-performance cementitious materials

This study investigates the impact of the chemical composition of superabsorbent polymers (SAPs) on their effectiveness in internal curing within high-performance cementitious materials. Although the use of commercial SAPs in cementitious systems has been widely researched, there is still no consensus on how different SAP structures influence material properties. For the first time, this research employs photoinitiated free radical polymerization technology to synthesize three structurally distinct SAPs: SAP with sulfonic acid groups (PAMPS), SAP with amide groups (PAM), and SAP with carboxyl groups (PAAs). The effects of these SAPs on the cement hydration process and microstructure were examined by analyzing their water absorption behavior in cement filtrate. The residual cation content on the SAP surface was evaluated using EDS, while XRD and TGA were used to study how SAP structure affects cement hydration products. Furthermore, the impact of these SAPs on the strength and autogenous shrinkage of the material was investigated. The results indicate that PAMPS, with its sulfonic acid groups, exhibited stable water absorption performance in the alkaline cement environment, promoting hydration reactions and increasing the formation of needle-shaped C-S-H. This stability contributed to mitigating the negative effects on mechanical properties. While the inclusion of SAPs generally reduced the strength of the cement matrix, PAMPS was the most effective in mitigating autogenous shrinkage, achieving a shrinkage mitigation efficiency of 86 %. These findings highlight the importance of SAP chemical structure in influencing cement hydration and material performance, offering insights for the development of effective internal curing agents to enhance high-performance concrete.

Increasing disparities in human exposure to perfluorooctanesulfonic acid: findings from per- and polyfluoroalkyl substance concentrations in 1999-2018 NHANES

The disparities in exposure to environmental hazards have fueled the environmental justice movement, which has garnered increasing attention and momentum over the past few decades. However, research addressing exposure disparities pertaining to chemicals remains notably limited. Here, leveraging data from the National Health and Nutrition Examination Survey spanning the period from 1999 to 2018, we unveiled that the perfluorooctanesulfonic acid (PFOS) exhibited the highest concentration in human biomonitoring in general U.S. population, with a mean value of 14.54 ± 19.59ng/ml. Subsequently, the mean concentrations of Perfluorooctanoic acid (PFOA), perfluorohexane sulfonic acid (PFHxS), perfluorononanoic acid (PFNA), and perfluorodecanoic acid (PFDA) were 3.33 ± 3.19, 2.29 ± 3.13, 1.07 ± 1.30, and 0.34 ± 0.71, respectively. Meanwhile, although females or Non-hispanic White exhibited relatively higher levels for most per- and polyfluoroalkyl substances (PFASs) compared to other groups. The individuals with higher household incomes demonstrated elevated exposure to PFASs. Interestingly, despite lower exposure burdens were observed in Non-Hispanic Black individuals, females, and individuals with low family income, we identified relatively higher exposure disparities in these populations. In particular, exposure disparities for general U.S. population exposure to PFOS exhibited an approximate 50% increase from 1999 to 2018, despite a concurrent decline of 84% in biomonitoring levels. Meanwhile, the population aging has led to an exacerbation of human exposure to PFOS by 12.4%. Our findings underscore the necessity of ensuring equitable protection from PFAS exposure for all populations, although further investigation is required to understand the underlying mechanisms driving these disparities.

Sulfonated polyphenylene oxide-based artificial lung membrane with prominent selectivity of CO2

The primary issues impeding oxygenation efficacy in extracorporeal membrane oxygenation (ECMO) are low CO2/O2 selectivity and insufficient permeability of CO2. Herein, sulfonated polyphenylene oxide (SPPO) was chosen as a candidate for the oxygenation membrane material. The CO2-affinitive sulfonic acid groups on the molecular chain of SPPO enhance the interaction between CO2 and the SPPO membrane; thereby, the CO2/O2 selectivity is effectively enhanced. When the solid content of the casting solution is 23%, the SPPO membrane achieves a CO2/O2 selectivity of 17.0, almost as selective as human alveoli. The blood clotting time, red blood cell adhesion, platelet adhesion, and hemolysis ratio were employed to evaluate the blood compatibility of SPPO materials. The results demonstrated that the manufactured SPPO membranes exhibited good hemocompatibility. This work offers novel thinking for researching and applying effective artificial lung membranes.