Sulfonic Acid Research Articles

UDP-glycosyltransferase UGT96C10 functions as a novel detoxification factor for conjugating the activated dinitrotoluene sulfonate in switchgrass.

Dinitrotoluene sulfonates (DNTSes) are highly toxic hazards regulated by the Resource Conservation and Recovery Act (RCRA) in the United States. The trinitrotoluene (TNT) red water formed during the TNT purification process consists mainly of DNTSes. Certain plants, including switchgrass, reed and alfalfa, can detoxify low concentrations of DNTS in TNT red water-contaminated soils. However, the precise mechanism by which these plants detoxify DNTS remains unknown. In order to aid in the development of phytoremediation resources with high DNTS removal rates, we identified and characterized 1-hydroxymethyl-2,4-dinitrobenzene sulfonic acid (HMDNBS) and its glycosylated product HMDNBS O-glucoside as the degradation products of 2,4-DNT-3-SO3Na, the major isoform of DNTS in TNT red water-contaminated soils, in switchgrass via LC-MS/MS- and NMR-based metabolite analyses. Transcriptomic analysis revealed that 15 UDP-glycosyltransferase genes were dramatically upregulated in switchgrass plants following 2,4-DNT-3-SO3Na treatment. We expressed, purified and assayed the activity of recombinant UGT proteins in vitro and identified PvUGT96C10 as the enzyme responsible for the glycosylation of HMDNBS in switchgrass. Overexpression of PvUGT96C10 in switchgrass significantly alleviated 2,4-DNT-3-SO3Na-induced plant growth inhibition. Notably, PvUGT96C10-overexpressing transgenic switchgrass plants removed 83.1% of 2,4-DNT-3-SO3Na in liquid medium after 28 days, representing a 3.2-fold higher removal rate than that of control plants. This work clarifies the DNTS detoxification mechanism in plants for the first time, suggesting that PvUGT96C10 is crucial for DNTS degradation. Our results indicate that PvUGT96C10-overexpressing plants may hold great potential for the phytoremediation of TNT red water-contaminated soils.

Sodium salt of dodecyl benzene sulphonic acid as an effective corrosion inhibition for different heat-treated steel in sulphuric acid medium

Abstract The purpose of this work is to use electrochemical and gravimetric techniques to investigate the inhibition of DBSS on the corrosion of heat-treated dual-phase AISI 1040 steel in a 0.5 M sulphuric acid solution at 35 °C. The corrosion studies are performed by potentiodynamic polarization study (PDP), electrochemical impedance study (EIS), and gravimetric method. To confirm the inhibition surface characterization like x-ray diffraction technique (XRD) analysis, scanning electron microscopy (SEM), and EDS analysis are performed. Depending on the phase change of metals due to heat treatment, the corrosion inhibition of the heat-treated metal increased when it was exposed to 0.5 M H2SO4 at 35 °C in the presence of dodecyl benzene sulphonic acid sodium salt (DBSS) inhibitor. The highest inhibition efficiency of 63%, 82%, 87%, 43%, and 63% was obtained for AISI 1040 steel at heat treatment conditions of Normalized, Quenched at 700 °C, Quenched at 750 °C, Quenched at 790 °C and Quenched at 900 °C respectively. In the gravimetric and electrochemical study, the IE increases with the increase with the concentration of DBSS unto 75% from gravimetric analysis and 87% from PDP analysis for Quenched at 750 °C and 790 °C respectively. The metal protection is achieved by heat treatment process as well as by using DBSS as inhibitor. Corrosion inhibition on the metal’s surface was confirmed by SEM and XRD. In addition, the adsorption of DBSS on the anodic and cathodic sites of the metal surface was well explained.

OS03-06 Aggregated exposure to perfluorooctane sulfonic acid coupled with PBPK model and parameter optimization using a human study for validation

OS03-06 Aggregated exposure to perfluorooctane sulfonic acid coupled with PBPK model and parameter optimization using a human study for validation

1, 3, 6, 8-pyrene sulfonic acid tetrasodium fluorescent pigment synthesis and security ink production

Colorants used in security inks are special pigments that radiate in the UV region or IR region. Obtained pigments can be from valuable rare earth elements or they can be organic based. Organic-based pigments are generally insoluble in water, which limits their use. For this purpose, an organic-based UV-radiating pigment was synthesized and made water-soluble by forming its salt. With the obtained salt-formed pigment, inkjet ink that can be used in counterfeiting was applied and its printability and resistance properties were determined. In this study, 1, 3, 6, 8-pyrene sulfonic acid tetrasodium salt was synthesized and water-based inkjet inks with hydroxy ethyl cellulose binder were produced. The prepared inks were printed on the paper surface. The color and gloss of the prints obtained were measured both in the visible region and in the UV region. Its optical properties were detected by UV spectroscopy. Strength properties such as light fastness, nitro resistance, alkali resistance, acid resistance, rub resistance, drying time, adhesion and dry film weight of the prints were determined. As a result; Inkjet ink with 1, 3, 6, 8-pyrene sulfonic acid tetrasodium salt was produced and it was concluded that it has good resistance properties.

Polyfluoroalkyl-Substances Detection in Junk Food Packing Materials Using Various Analytical Methods: A Review.

Per- and polyfluoroalkyl substances (PFAS) are unseen, dangerous organic compounds that can cause major health disorders. PFASs have been categorized as persistent, bioaccumulative, and toxic (PBT). This review provides knowledge about the PFASs present in junk food packaging materials, which can migrate into the food. Different types of samples were analyzed using the analytical methods. The most preferred method of extraction is ultrasonic-assisted extraction (UAE). It summarizes the analytical approaches of PFASs. The results of numerous studies show that perfluorooctanoic acid is the most often detected compound with high concentrations. The European Food Safety Authority (EFSA) announced that the tolerable weekly intake (TWI) of PFASs is 4.4 ng/kg. The US Environmental Protection Agency (EPA) has announced the limit for perfluorobutane sulfonic acid due to its toxicity level. These compounds have potential effects on both people's health and the biosphere. PFAS usage has to stop in the industries for a better future.

Maternal Exposure to Per- and Polyfluoroalkyl Substances and Offspring Chromosomal Abnormalities: The Japan Environment and Children's Study.

Although recent in vitro experimental results have raised the question of whether maternal exposure to per- and polyfluoroalkyl substances (PFAS) may be a potential environmental risk factor for chromosomal abnormalities, epidemiological studies investigating these associations are lacking. This study examined whether prenatal PFAS exposure is associated with a higher prevalence of chromosomal abnormalities among offspring. We used data from the Japan Environment and Children's Study, a nationwide birth cohort study, and employed logistic regression models to examine the associations between maternal plasma PFAS concentrations in the first trimester and the diagnosis of chromosomal abnormalities in all births (artificial abortions, miscarriages, stillbirths, and live births) up to 2 years of age. In addition, we examined associations with mixtures of PFAS using multipollutant models. The final sample consisted of 24,724 births with singleton pregnancies, of which 44 confirmed cases of chromosomal abnormalities were identified (prevalence: 17.8/10,000 births). When examined individually, exposure to perfluorononanoic acid (PFNA) and perfluorooctane sulfonic acid (PFOS) showed positive associations with any chromosomal abnormalities with age-adjusted odds ratios of 1.81 (95% CI: 1.26, 2.61) and 2.08 (95% CI: 1.41, 3.07) per doubling in concentration, respectively. These associations remained significant after Bonferroni correction, although they did not reach the adjusted significance threshold in certain sensitivity analyses. Furthermore, the doubling in all PFAS included as a mixture was associated with chromosomal abnormalities, indicating an age-adjusted odds ratio of 2.25 (95% CI: 1.34, 3.80), with PFOS as the predominant contributor, followed by PFNA, perfluoroundecanoic acid (PFUnA), and perfluorooctanoic acid (PFOA). The study findings suggested a potential association between maternal exposure to PFAS, particularly PFOS, and chromosomal abnormalities in offspring. However, the results should be interpreted cautiously, because selection bias arising from the recruitment of women in early pregnancy may explain the associations. https://doi.org/10.1289/EHP13617.

Corncob waste derived carbon with sulfonic acid group: An efficient heterogeneous catalyst for production of ethyl levulinate as biodiesel additives

Alkyl levulinate is a biomass-based chemical compound used as a fuel additive. This research aims to produce ethyl levulinate from levulinic acid and ethanol using esterification with the assistance of a heterogeneous sulfonated carbon catalyst. The carbon sulfonate catalyst is obtained from corncob waste that has undergone carbonization at 300 °C and sulfonation using sulfuric acid at a temperature of 150 °C for 8 h. The catalyst is used for esterification with predetermined operating variables using Box-Behnken Design (BBD) on the response surface methodology (RSM). The result shows significant variables for ethyl levulinate esterification are catalyst loading and esterification time. The FTIR analysis indicates the presence of S=O bonds in the sulfonated carbon catalyst. The XRD and SEM analysis shows that the sulfonated carbon catalyst is in amorphous and mesoporous form. Catalyst reusability demonstrates that the corncob-derived carbon sulfonate catalyst can be used up to 3 times. The optimum condition for esterification is 9 h of reaction, 10 % catalyst loading, and a molar ratio of levulinic acid to ethanol of 1:10, which has 83.15 % conversion. These results present the optimum parameter conditions for an efficient heterogeneous catalyst from corncob for producing ethyl levulinate.

Highly Efficient Production of Furfural from Corncob by Barley Hull Biochar-Based Solid Acid in Cyclopentyl Methyl Ether–Water System

Furfural, an important biobased compound, can be synthesized through the chemocatalytic conversion of D-xylose and hemicelluloses from lignocellulose. It has widespread applications in the production of valuable furans, additives, resins, rubbers, synthetic fibers, polymers, plastics, biofuels, and pharmaceuticals. By using barley hulls (BHs) as biobased support, a heterogeneous biochar Sn-NUS-BH catalyst was created to transform corncob into furfural in cyclopentyl methyl ether–H2O. Sn-NUS-BH had a fibrous structure with voids, a large comparative area, and a large pore volume, which resulted in more catalytic active sites. Through the characterization of the physical and chemical properties of Sn-NUS-BH, it was observed that the Sn-NUS-BH had tin dioxide (Lewis acid sites) and a sulfonic acid group (Brønsted acid sites). This chemocatalyst had good thermostability. At 170 °C for 20 min, Sn-NUS-BH (3.6 wt%) was applied to transform 75 g/L of corncob with ZnCl2 (50 mM) to generate furfural (80.5% yield) in cyclopentyl methyl ether–H2O (2:1, v/v). This sustainable catalytic process shows great promise in the transformation of lignocellulose to furfural using biochar-based chemical catalysts.

Effect of chromophore type on efficiency of reactive dye removal using polyamidoamine dendrimer

AbstractIn this study, by selecting a sample of dyes from a wide variety of chromophores used in the production of reactive dyes (monoazo, bisazo, metal azo, phthalocyanine, anthraquinone, copper formazan and triphendioxazine), the colour removal performance of polyamidoamine (PAMAM) dendrimer in reactive dyes was statistically evaluated depending on the dye chromophore groups (and accordingly molecular weight and number of sulfo groups of the dye), dendrimer concentration and centrifugation time. When all the results were examined, it was observed that the colour removal efficiency was significantly lower in metalazo and copper formazan‐based reactive dyes, whereas colour removals ranging from 93% to 98% could be obtained in bisazo, triphendioxazine, monoazo, anthraquinone and phthalocyanine dyes. With the use of dendrimer, the best colour removal efficiencies occurred at pH 3. However, it was found that the centrifugation time of 15 min is sufficient for all dyes, and a longer centrifugation does not provide any additional benefit in terms of colour removal.

Addressing the Challenge of a Simultaneous Destructive Assay of Plutonium and Uranium: Highly Precise, Robust, Universal, and Reagent-Free Differential Pulse Voltametric Method Development in Biodegradable Methanesulfonic Acid Medium.

The destructive assay of bulk uranium and plutonium, a cornerstone for chemical quality control and nuclear material accounting of fuel matrices, mandates robust and precise methodologies. Despite ongoing research, simultaneous, matrix independent determination of U and Pu has eluded solution owing to inherent limitations in aqueous acid medium, viz., coexistence of multiple oxidation states, coupled electrochemical reactions, smaller potential window, and requirement for multistep sample preconditioning and tedious electrode modification. The present study addresses this challenge wherein non-aqueous methanesulfonic acid (MSA) served the dual role of solvent and analyte media with a bare glassy carbon (GC) electrode. Fuel matrices, viz., (U, Pu)C, (U, Pu)O2, PuO2, UO3, UO2, and U3O8, were quantitatively dissolved in biodegradable MSA, without using any additives. Redox speciation of the analytes, U and Pu, in MSA was probed by ultraviolet-visible spectrophotometry and electrometry, revealing the absence of electrocatalytic regeneration and stabilization of single oxidation state, viz., U(VI) and Pu(IV), along with relevant redox-energetic (electron transfer and reversibility) and kinetic data. Bidentate coordination of MSA with the U analyte was indicated by X-ray absorption spectroscopy studies and was corroborated by density functional theory-based investigations, providing the optimized structure, viz., [UO2(MSA)2] and [Pu(MSA)4], binding modes and energy, partial charges, and molecular orbital diagrams. Based on these insights, the feasibility of differential pulse voltammetry (DPV)-based assay method development for U and Pu separately and in different U/Pu ratios, representing assorted fuel matrices, was probed. Analytical figures of merit for both U and Pu (detection limit of ∼10-5 M, precision of ∼0.2%, accuracy of ∼0.2%, high sensitivity, repeatability, and non-influence of relevant interferences) were determined, method validated employing actual fuel samples, and compared with the established, multi-step biamperometry method. Hence, a universal, simultaneous U and Pu destructive assay method in non-aqueous MSA media based on DPV with a commercial GC electrode was demonstrated.

The efficient oxidation of waste resins via ternary alkali carbonate: Mechanisms of the Fe3+/Co2+-catalysis for enhanced fixing organic sulfur, iron and cobalt

The development of a highly efficient and cost-effective strategy for the fixation of organic sulfur, as well as radioactive metal nuclides holds great significance in the treatment of organic contaminants. Herein, ternary molten carbonate (Li2CO3-Na2CO3-K2CO3) was used for treating simulated waste resins containing Fe3+ and Co2+ (Fe-Co-CERs). The FT-IR and XPS analysis showed that the significant conversion process of organic sulfur in molten Li2CO3-Na2CO3-K2CO3 was sulfonic acid group (−SO3-) → sulfuryl group (−SO2-) → sulfur bond (−S-). The TG-DTG curves and the activation energy (E) revealed Fe3+ and Co2+ possess self-catalysis during the oxidation of Fe-Co-CERs, wherein distinctly facilitated the decomposition of −SO3- and −S- structures. The produced SO2 was further absorbed by molten carbonate to generate sulfate, which was confirmed by the observed increase in SO42- and the corresponding decrease of CO32–. The conversion of LiNaSO4 to K3Na(SO4)2 revealed that Li2CO3 is to function as a sulfur catcher at temperatures below 400 °C, which then as a crucial heat transfer medium at temperatures above 400 °C. The predominant forms of Fe and Co at 700 °C were primarily Co8FeS8, FeS, and CoS, which underwent oxidation to form CoFe2O4 and CoSO4 at 800 °C. The retention rate of S, Fe and Co reached 94.36 %, 97.48 % and 98.35 %, respectively. This molten salt oxidation (MSO) strategy exhibits promising potential for the treatment of organic contaminants containing sulfur and multiple metal elements.

Investigation of the Deionization Rate of Asymmetric Capacitive Deionization Technology for the Treatment of Short-Chain Perfluoroalkyl Substances (PFAS)

Objectives : This study aims to introduce and evaluate the effectiveness of asymmetric membrane capacitive deionization (ACDI) in removing short-chain perfluoroalkyl substances (PFAS), specifically perfluorobutane sulfonic acid (PFBS), from aqueous solutions. This study offers important insights for the advancement of CDI technology in the sustainable treatment of industrial wastewater containing PFAS.Methods : ACDI was employed by removing the anion exchange membrane from conventional membrane capacitive deionization system. The effect of key operational parameters such as voltage (0.5~1.2 V), initial concentration (50~500 mg/L), and flow rate (1~5 ml/min) on PFBS removal efficiency was systematically investigated. Additionally, PFBS removal performance in the presence of chloride ions was also investigated to determine competing ion effects.Results and Discussion : The ACDI system significantly outperformed both CDI and MCDI, achieving a maximum deionization rate of 0.032 mg/g/s, compared to 0.012 mg/g/s for CDI and 0.01 mg/g/s for MCDI. Increasing the applied voltage from 0.5 V to 1.2 V enhanced the deionization rate, with the highest rate observed at 1.2 V. Higher initial PFBS concentrations also improved the deionization rate, increasing from 0.0009 mg/g/s at 50 mg/L to 0.032 mg/g/s at 500 mg/L. The optimal flow rate was found to be 2 ml/min, balancing ion contact time and throughput, resulting in the highest deionization rate. The presence of competing ions, such as chloride, reduced PFBS removal efficiency, as shown by the decrease in deionization rate when NaCl was added to the feed solution.Conclusion : Overall, the ACDI system demonstrated superior deionization capacity and energy efficiency for PFBS removal, highlighting its potential as a sustainable and efficient technology for treating water contaminated with short-chain PFAS. Future research should address the challenges posed by competing ions in real-world wastewater to further optimize the ACDI system’s performance.

RAPID AND AN EFFICIENT ONE-POT THREE-COMPONENT SYNTHESIS OF ISOXAZOLES PROMOTED BY CAS

A straightforward, practical, and economical process for producing isoxazole derivatives is described. It makes use of ethylacetoacetate, hydroxylamine hydrochloride, and substituted aromatic aldehydes with promoted camphor sulfonic acid as a catalyst in a solvent. No toxic organic solvents are used in the current procedure. Shortest reaction time, high product yields, easy work-up process, and non-chromatographic product purification are only a few of this catalysts encouraging reaction response characteristics. The derivatives of desired compounds were analyzed advanced spectroscopic data by 1H NMR, 13CNMR and mass spectrometry was used to verify the products structures. Products were chosen, and their antibacterial activity was examined.

A Study on the efficiency of organic activator application to process refractory hard-to-beneficiate raw materials

Polymetallic ores with complex mineralogical compositions pose significant challenges in flotation beneficiation, often resulting in suboptimal separation and recovery of valuable minerals. This study aims to analyse the effectiveness of alkyl benzene sulfonic acid (ABSA) as a frothing activator in improving the flotation performance and mineral recovery of polymetallic ore. It presents the results of flotation beneficiation experiments for polymetallic ore of complex mineralogical composition. Experiments were conducted on polymetallic ore samples using ABSA as the frothing activator in the flotation process. The performance was evaluated based on recovery rates and separation efficiency, comparing the results with standard floating frothing agents. The findings showed the highest efficiency of ABSA application for samples of mixed-type ores in increasing the recovery of gold, copper, zinc and lead in the collective concentrates of flotation beneficiation. ABSA activator promotes additional cleaning of fragments containing valuable metals from oxide films and coatings and the transfer of valuable metals' microparticles due to the organics' adsorption properties and the formation of metal-carbon bonds. Another effect of using this reagent is there was an increase in concentrate mass yield while maintaining the quality parameters. A similar effect was observed for beneficiation of copper ore with complex composition - copper recovery in the main concentrate increased. Selective flotation with the development of gold concentrate from hard-to-beneficiate polymetallic ore also showed a significant increase in gold recovery with ABSA pretreatment.

Experimental and theoretical computational study of corrosion inhibitors in the cobalt bulk chemical mechanical polishing (CMP) process

Cobalt is a potential substitute for copper as local interconnects in sub-10 nm interconnects, the chemical mechanical polishing (CMP) of which is quite challenging due to the high chemical reactivity of Co. By using a combination of experiments and theoretical calculations, the optimum corrosion inhibitor of Co is identified and the corrosion inhibition mechanism of TTLYK on Co is further investigated. It investigates the effects of various corrosion inhibitors, including potassium oleate, dodecyl benzene sulphonic acid, octyl hydroxamic acid, and 2,2′-[[(methyl-1H-benzotriazol-1yl) methyl] imino] bis-ethanol (TTLYK) on Co through chemical mechanical polishing and static etching experiments. The results show that among various corrosion inhibitors, TTLYK presents the best corrosion inhibition effect. When the basic slurry contains 10 mM TTLYK, the corrosion inhibition efficiency could reach 96.23 %, the material removal rates of Co is 161.79 nm/min, the static etching rates is 0.85 nm/min, and the material removal selectivity ratio of Co and Ti is 39:1. The results fully meet the requirements of the Co bulk CMP process. It is revealed TTLYK could form a protective layer with a synergistic physical and chemical adsorption on Co, in which the chemical adsorption occurs through the formation of CoN bonds. The adsorption of TTLYK could decelerate the transformation of CoO and Co(OH)2 to Co3O4, and the as formed Co-TTLYK complex provides the main corrosion inhibition.

Synthesis of pyrrolo[1,2-a]quinoline and pyrrolo[1,2-b]isoquinoline derivatives via intramolecular acylation

A methanesulfonic acid mediated intramolecular acylation approach for the synthesis of pyrrolo[1,2-a]quinoline and the isomeric pyrrolo[1,2-b]isoquinoline frameworks has been developed. The reaction is carried out at ambient temperature and no Lewis acid catalyst is required. The product yields are generally good to excellent.

Consolidating two-dimensional liquid chromatography–high-resolution tandem mass spectrometry (LC×LC-HRMS/MS) technique for the non-targeted analysis of poly- and perfluorinated substances: A trial on aqueous film-forming foams

To date, poly- and perfluoroalkyl substances (PFAS) represent a real threat for their environmental persistence, wide physicochemical variability, and their potential toxicity. Thus far a large portion of these chemicals remain structurally unknown. These chemicals, therefore, require the implementation of complex non-targeted analysis workflows using liquid chromatography coupled with high-resolution mass spectrometry (LC-HRMS) for their comprehensive detection and monitoring. This approach, even though comprehensive, does not always provide the much-needed analytical resolution for the analysis of complex PFAS mixtures such as fire-fighting aqueous film-forming foams (AFFFs). This study consolidates the advantages of the LC×LC technique hyphenated with high-resolution tandem mass spectrometry (HRMS/MS) for the identification of PFAS in AFFF mixtures. A total of 57 PFAS homolog series (HS) were identified in 3M and Orchidee AFFF mixtures thanks to the (i) high chromatographic peak capacity (n’2D,c ~ 300) and the (i) increased mass domain resolution provided by the “remainder of Kendrick Mass” (RKM) analysis on the HRMS data. Then, we attempted to annotate the PFAS of each HS by exploiting the available reference standards and the FluoroMatch workflow in combination with the RKM defect by different fluorine repeating units, such as CF2, CF2O, and C2F4O. This approach resulted in 12 identified PFAS HS, including compounds belonging to the HS of perfluoroalkyl carboxylic acids (PFACAs), perfluoroalkyl sulfonic acids (PFASAs), (N-pentafluoro(5)sulfide)-perfluoroalkane sulfonates (SF5-PFASAs), N-sulfopropyldimethylammoniopropyl perfluoroalkane sulfonamides (N-SPAmP-FASA), and N-carboxymethyldimethylammoniopropyl perfluoroalkane sulfonamide (N-CMAmP-FASA). The annotated categories of perfluoroalkyl aldehydes and chlorinated PFASAs represent the first record of PFAS HS in the investigated AFFF samples.

Structural investigation of the complexation between vitamin B12 and per- and polyfluoroalkyl substances: Insights into degradation using density functional theory

Environmental remediation of per- and polyfluoroalkyl substances (PFAS) has become a significant research topic in recent years due to the fact that these materials are omnipresent, resistant to degradation and thus environmentally persistent. Unfortunately, they have also been shown to cause health concerns. PFAS are widely used in industrial applications and consumer products. Vitamin B12 (B12) has been identified as being catalytically active towards a variety of halogenated compounds such as PFAS. It has also been shown to be effective when using sulfide as a reducing agent for B12. This is promising as sulfide is readily available in the environment. However, there are many unknowns with respect to PFAS interactions with B12. These include the reaction mechanism and B12's specificity for PFAS with certain functionalization(s). In order to understand the specificity of B12 towards branched PFAS, we examined the atomistic interactions between B12 and eight different PFAS molecules using Density Functional Theory (B3LYP/cc-pVDZ). The PFAS test set included linear PFAS and their branched analogs, carboxylic acid and sulfonic acid headgroups, and aromatic and non-aromatic cyclic structures. Conformational analyses were carried out to determine the lowest energy configurations. This analysis showed that small chain PFAS such as perfluorobutanoic acid interact with the cobalt center of B12. Bulkier PFAS prefer to interact with the amine and carbonyl groups on the sidechains of the B12 ring system. Furthermore, computed complexation energies determined that, in general, branched PFAS (e.g. perfluoro-5-methylheptane sulfonic acid) interact more strongly than linear molecules (e.g. perfluorooctanesulfonic acid). Our results indicate that it may be possible to alter the interactions between B12 and PFAS by synthetically modifying the sidechains of the ring structure.

Template-free synthesize of PANI nanostructures: Modulating structure for enhanced dielectric characteristics and superior electromagnetic wave absorption

To provide electromagnetic protection for intelligent equipment, advanced electromagnetic wave absorption (EWA) materials are highly desired. To reveal the interaction mechanism of structure and electromagnetic waves, polyaniline (PANI) with various structures, including nanosheets, clusters, and nanofibers, is synthesized via a template-free approach. The self-assembly process of PANI can be regulated by camphor sulfonic acid due to the formation and guidance of charge transfer complexes. A comprehensive analysis of structure, chemical constitution, and electromagnetic characteristics is conducted. Clusters with three-dimensional micro-nano structure exhibit superior microwave absorption, achieving a minimum reflection loss of −52.22 dB at 9.84 GHz with a 3.2 mm thickness and an absorption bandwidth of 6.12 GHz at 2.3 mm thickness. The outstanding EWA performance is attributed to the unique architecture, strong dielectric loss capabilities, and effective impedance matching. Moreover, the fabrication process is cost-effective and scalable, making it conducive to practical applicability.

Preparation of functionalized magnetic nanoparticles bearing sulfonic acid as an effective reusable solid acid catalyst for the synthesis of benzothiazoles

In this study, solid acid magnetic nanoparticles Fe3O4@SiO2-S-Bu-SO3H were prepared under appropriate conditions and characterized by various analytical techniques including FT-IR, XRD, FE-SEM, EDX, and VSM. Finally, the catalytic activity of the synthesized Fe3O4@SiO2-S-Bu-SO3H MNPs was investigated for the synthesis of valuable benzothiazole derivatives by the condensation reaction of ortho-aminothiophenol and various aldehydes under ultrasonic conditions. In the presence of the inexpensive, environment-friendly, magnetically recoverable solid acid catalyst, the benzothiazoles were obtained as pure target products in excellent yields (90–98%) and short reaction times (3–11 min). The synthesized Fe3O4@SiO2-S-Bu-SO3H MNPs show great catalytic activity because of the combined effect of Brønsted acidity and high functional group density. This solid acid magnetic nanocatalyst is reusable for several cycles and can be easily segregated from the reaction mixture.