Benzidine Research Articles

A comprehensive Investigation of Donor-Acceptor anthraquinone derivatives as Versatile and efficient photosensitizers for Dye-Sensitized solar cells

A new metal-free anthraquinone donor–acceptor-π-anchor (D-A-π-A) design was developed using unsymmetrically substituted anthraquinone (ATQ) derivatives functionalized with bromine (Br), diphenylamine (DPA), indoline (Ind), BrATQBzOH, DPAATQBzOH, and IndATQBzOH. The synthesised compounds, functionalized with an anchor group (ethynylbenzoic acid), were evaluated in practical dye-sensitised solar cell, DSSC, devices with the aiming to improve electron injection efficiency. Their properties and applicability were analysed and rationalised based on their energy levels and parameters derived from the current–voltage (I-V) curve analysis in real devices. Femtosecond transient absorption measurements of the sensitiser IndATQBzOH with TiO2 revealed distinct excited state dynamics and charge transfer properties, highlighting the influence of the semiconductor interface. In addition, Density Functional Theory (DFT) and Time-Dependent DFT (TDDFT) electronic quantum calculations were performed, which revealed that the new anthraquinone-based dyes exhibit optimal coplanarity for efficient electron transfer, with their LUMO and HOMO energy levels facilitating electron injection into TiO2. In contrast to the low efficiencies found for previous anthraquinone derivatives, with maximum photocurrent efficiencies (PCE) below 0.2%, 9,10-anthraquinone derivatives were used as acceptors attached to suitable donors (DPA or Ind), and PCE above 1% were obtained.

Reactions of Diphenylamine with OH Radicals in the Environment: Theoretical Insights into the Mechanism, Kinetics, Temperature, and pH Effects.

Diphenylamine (DPL) has been widely utilized in industrial chemicals, but its degradation by HO• radicals in the environment has not been fully studied yet. The present study uses quantum chemical calculations to evaluate the reaction of DPL with HO• radicals in atmospheric and aqueous environments. The results showed that, in the atmosphere, the diphenylamine reacted with the HO• radical rapidly, with an overall rate constant of 9.24 × 1011 to 1.34 × 1011 M-1 s-1 and a lifetime of 0.17 to 1.55 h at 253-323 K. The calculated overall rate constant in water (koverall = 1.95 × 1010 M-1 s-1, pH = 3-14) is in excellent agreement with the experimental value (koverall = 1.00 × 1010-1.36 × 1010 M-1 s-1). The HO• + DPL reaction in water could occur following the hydrogen transfer (15.4%), single electron transfer (41.6%), and radical adduct formation (41.7%) mechanisms, clarifying that addition products were not exclusive products. Nevertheless, variations in temperature and pH within aqueous environments had an impact on the mechanisms, kinetics, and degradation products of the reaction of DPL with HO• radicals.

A covalent organic framework-derived pretreatment for pesticides in vegetables and fruits

Sample pretreatment is an essential procedure in pesticide analysis, as the matrix effect can significantly influence the results. In this study, a covalent organic framework (COF) was synthesized using 1,2,4,5-tetrakis-(4-formylphenyl)benzene (TFPB) and benzidine (BD) to mitigate the matrix effect in vegetable and fruit samples. This COF was then used to develop a solid-phase extraction (CSPE) method. In addition, the COF was used to create a magnetic COF (MCOF) for use in magnetic solid-phase extraction (MSPE). The synthesized COF and MCOF were thoroughly characterized using scanning electron microscopy (SEM) for morphological analysis, Fourier-transform infrared spectroscopy (FT-IR) for chemical bond identification, and N2 adsorption–desorption measurements for porosity and surface area assessment. Key pretreatment parameters such as buffers, dilution rate, sorbent dosage, extraction time, elution solvent, and reuse number were optimized. The developed CSPE and MSPE showed excellent purification ability for the matrix of vegetable and fruit samples. The reuse test demonstrated that the synthesized COF and MCOF can be reused up to 15 times. Moreover, the developed CSPE and MSPE showed acceptable recoveries in spiked recovery tests, suggesting that these pretreatment methods were feasible for sample purification in pesticide analysis.

Development and workflow of a separation process for optimum design: A case of phenylenediamine

AbstractAn industrial project based upon the multi‐scale objective‐oriented process development (MOPD) method for developing an optimum process for separating phenylenediamine (PDA) isomers was executed. This article reports the first four (4) steps of that project. In the first step, the solution for this separation problem was conceptualized. It is a distillation‐crystallization‐hybrid process. The second step is to validate the concept experimentally from the thermodynamic point of view followed by kinetic considerations. It was found that a 2‐stage crystallization is required to purify the main product isomers to the desirable specification that is higher than 99.5 mol%. A heat and material balance model was then constructed for analyzing and optimizing various design variables, also used to understand the operability of the process. Finally, with proper HAZOP analysis and detailed engineering, the pilot unit was designed. Throughout the project, all exercises and efforts are well focused with clear objectives, hence there are minimum detours on the execution; furthermore, the clear objectives enhanced the communications among various disciplines tremendously. It is a valuable asset for senior management in the allocation of resources and budgets.

Readily constructed squaraine J-aggregates with an 86.0 % photothermal conversion efficiency for photothermal therapy

The development of photothermal agents with high photothermal conversion efficiency (PCE) and long absorption wavelengths is crucial for safe and effective anti-cancer treatment. However, achieving these advantages often requires precise molecular design and complex synthetic procedures. In this study, we present a simple, precise, and effective method for fabricating photothermal agents with high PCE using long wavelength excitation. This approach involves linking two electron-donating components, diphenylamine (DPA), and an electron-withdrawing squaraine (SQ), via a π-bridge thiophene (T). The resulting D-π-A-π-D structure leads to a red-shifted absorption band. Within the DTS structure, DPA functions as a molecular rotor, T serves as a coplanar backbone, and SQ promotes J aggregation. When DTS nanoparticles (NPs) are fabricated using an amphiphilic nano-carrier, the maximum absorption wavelength shifts from 701 to 803 nm. This shift is accompanied by reduced fluorescence and an exceptionally high PCE of 86.0 %. Both in vitro and in vivo assessments confirm that DTS NPs exhibit strong potential for photothermal antitumor therapy. Overall, this strategy offers a valuable framework for designing photothermal agents with clinical applications in mind, offering a simpler and more efficient approach to achieving high PCE and long absorption wavelengths.

Formation of Nitrosamines from the Heterogeneous Reaction of Nitrous Acid and Organic Amines in Indoor Environments.

Carcinogenic nitrosamines have been widely studied due to their risk to human health. However, the universality and evolutionary processes of their generation, particularly concerning their secondary sources, remain unclear at present. We demonstrated through laboratory flow tube experiments that corresponding nitrosamines were generated from heterogeneous reactions of nitrous acid (HONO) with five structurally diverse amines commonly found indoors, including diphenylamine (DPhA), dibenzylamine (DBzA), dioctylamine (DOtA), N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine (6PPD), and N-phenyl-1-naphthylamine (PANA). The heterogeneous reaction rate constants of DBzA and DOtA with HONO (∼70 ppb) were 1.21 × 10-3 and 2.13 × 10-3 min-1 at 30% relative humidity (RH), resulting in a lifetime of 13.8 and 7.8 h. As compared to higher RH (∼80%), more nitrosamines were produced from the reaction of HONO with surface-sorbed DBzA, DOtA, 6PPD, and PANA at lower RH (30%), with product yields ranging from <0.1% to 0.5%. Furthermore, we observed the formation of nitroso-6PPDs and nitro-6PPDs during room air exposure of 6PPD in a genuine indoor environment, in addition to various other transformation products indicative of reactions of 6PPD with HONO, NOx, and ozone indoors. This study confirmed the universality of the heterogeneous reaction of surface-sorbed amine with HONO as a source of nitrosamines indoors.

Metal-organic framework-derived hierarchical flower-like DyCo-layered double hydroxide amalgamated nitrogen-doped graphene for diphenylamine detection in fruit samples: Theoretical density functional theory interpretation

Diphenylamine (DPA) is an environmental pollutant that can be potentially toxic. As a result, it is crucial to use basic and affordable analytical techniques to detect DPA. Electrochemical detection of DPA is a cost-effective and simple method. Modifying the electrodes with nanomaterials can enhance the electrochemical characteristics and sensitivity of the sensor. Herein, metal-organic framework (MOF) derived dysprosium cobalt-layered double hydroxide integrated nitrogen-doped graphene (DyCo-LDH/NG) is reported for the fabrication of the DPA sensing platform. The electrochemical oxidation of DPA is enhanced by the exceptional electrocatalytic activity and electron transfer properties of the DyCo-LDH/NG nanocomposite. Interestingly, the glassy carbon electrode (GCE) modified with DyCo-LDH/NG nanocomposite demonstrates a large linear detection range (0.05-470μM) and a low limit of detection (0.012µM). The density functional theory (DFT) study is employed to examine the energy levels and electron transfer sites of DPA during the electro-oxidation process. Furthermore, the practical efficiency test of the developed DPA sensor demonstrates a substantial recovery in fruit samples.

Anti-Cancer Activity, DFT and molecular docking study of new BisThiazolidine amide

In this study, a series of bis amide thiazolidine derivatives (Q1-Q6) were synthesized and their anticancer activity was evaluated against prostate (PC3) and breast (MCF7) cancer cells and normal cells line activity was evaluated against breast (MCF10), prostate (PNT1A) and living human cells (HUVEC) cancer cells. The thiazolidine rings were built from penicillamine and aromatic aldehydes (A1-A6), then converted to acetyl thiazolidines (B1-B6) using acetic anhydride, and finally linked with phenylene diamine to form the final compounds (Q1-Q6). Notably, compounds Q1 and Q3 displayed the highest activity against PC3, with IC50 values of 81 and 89 µg/ml, respectively. Docking simulations were performed for Q1, Q4, and Q5 against protein structures related to cancer (2FVD and 1SJ0). Additionally, DFT calculations were used to determine various molecular properties like HOMO/LUMO energies, band gap, and other descriptors, providing insights into the compounds’ stability and reactivity.

Rhodopin Incorporated into the &lt;i&gt;Allochromatium vinosum&lt;/i&gt; LH2 Complex Is Able to Generate Singlet Oxygen under Illumination

DPA membranes from Allochromatium vinosum cells, in which carotenoid biosynthesis was inhibited using diphenylamine (DPA) were obtained, into which rhodopin was incorporated. The LH2 complex with rhodopin content of 85% was isolated. Using a test for the thermal stability of LH2 complexes (DPA and with incorporated rhodopin), it was established that carotenoids of the early stages of biosynthesis (≤1 molecules per complex) did not interfere with rhodopin incorporation. It was found that when the LH2 complex with incorporated rhodopin was irradiated with light at the wavelength of 502 nm, BChl850 was photobleached at a rate close to that in the control LH2 complex. This indicates that rhodopin, after being incorporated into the DPA LH2 complex, is capable of generating singlet oxygen under illumination. Previously obtained data on heterogeneity of the carotenoid composition in DPA LH2 complexes (variation in the number of individual carotenoids molecules per complex in the general population) and our earlier suggestion about the structural role of carotenoids, namely, their ability to stabilize the LH2 complexes, were confirmed. Based on analysis of our results, as well as of the literature data, the interaction of singlet oxygen and carotenoids is discussed.

New blue emitters based on anthracene through charge transfer control

We designed new moieties with varying electron-donating effects and sizes based on diphenylamine and introduced them into anthracene to synthesize three types of emitting materials. All three materials exhibited high thermal stability with glass transition temperatures above 175°C, confirming their potential as OLED emitters. Devices doped with N9,N9,N10,N10-tetraphenylanthracene-9,10-diamine (TAD), where diphenyl amine is substituted on both sides, and N9,N10-di([1,1′-biphenyl]-4-yl)-N9,N10-bis(dibenzo[b,d]furan-2-yl)anthracene-9,10 diamine (ABFA), with a fused side group of diphenyl amine and dibenzofuran, showed EQEs of 1.28 % and 3.57 % respectively. Due to the intramolecular charge transfer (ICT), they exhibited ELmax values at 517 nm and 538 nm. On the other hand, the device doped with N,N′-(anthracene-9,10-diylbis(4,1-phenylene))bis(N-([1,1′-biphenyl]-4-yl)dibenzo[b,d]furan-2-amine) (APBFA), which has optimized side groups that suppress ICT and intermolecular packing, achieved a relatively high EQE of 4.48 % and showed blue emission with CIE coordinates of (0.146, 0.142).

Non-enzymatic detection of versatile anti-oxidant in diverse media using 3D spinel nickel cobalt oxide with 2D tungsten carbide nanohybrid heterostructure electrocatalyst

Diphenylamine (DPA), an organic amine derivative compound widely used in agriculture and polymer industries as an anti-scaling and anti-oxidising agent. The excessive and prolonged usage of DPA in agricultural products would result in the accumulation of it. The poor degradation ability and associated health hazards marked it as a “contaminant of emerging concern”. Since DPA is not completely banned in many countries, measuring the trace levels of DPA is essential to ensure the safety of the ecosystem. Therefore, the electrochemical sensing method was applied for the precise detection of an infinitesimal concentration of this component. In this work, we have prepared a spinel nickel cobalt oxide with a tungsten carbide (NCO/WC) electrocatalyst-based electrochemical sensor for the accurate detection of DPA. The structural, and morphological details were examined with Powder X-ray diffraction (PXRD), Fourier transform infrared spectroscopy (FT-IR), Field emission scanning electron microscope (FE-SEM), Transmission electron microscope (TEM), X-ray photoelectron spectroscopy (XPS), and Brunauer-Emmett-Teller (BET) analyses. The electrochemical properties were evaluated with impedance and voltammetric measurements. Various voltammetric techniques were utilized to assess the efficiency of NCO/WC towards DPA. Significantly, our sensor displayed a low detection (0.001 µM), and low quantification (0.0048 µM) limits, good linear range (0.01 to 147 µM), optimal sensitivity (1.716 µA µM−1 cm−2), remarkable selectivity, appreciable repeatability, reproducibility, and stability performance outcomes. Then, the sensor was employed to monitor the DPA in various matrices like agricultural, environmental, and human samples and conquered astonishing results. These findings suggest that our NCO/WC-based electrochemical sensor is a promising platform for the enhanced detection of DPA.

Unpuzzling spatio-vertical and multi-media patterns of aniline accelerators/antioxidants in an urban estuary

Aniline accelerators and antioxidants (AAs) are high-production-volume industrial additives that have recently attracted emerging concern given their ubiquity in environmental compartments and the associated (eco)toxic effects. Nonetheless, available information on the multi-media behavior of AAs and their transformation products (TPs) remains scarce. Therefore, we determined the residues of twenty-four AA(TP)s in paired dissolved phases (i.e., filtered water), suspended particulate matter (SPM), and sediment samples collected from the Yangtze River Estuary (YRE), a highly urbanized estuary in the East China. The median total concentrations of targeted compounds were 0.73 ng/g dw, 34.4 ng/L, and 39.6 ng/L in sediments, surface and bottom water, respectively. Diphenylamine (DPA) was the most abundant congener in SPM, while 1,3-diphenylguanidine (DPG) and dicyclohexylamine (DChA) dominated in the dissolved phases and sediments. Various anthropogenic emissions and (a)biotic degradation may collectively shape the matrix-specific accumulation patterns and spatial trends of these compounds across the YRE. However, the vertical patterns of AA(TP)s were obscure, probably due to the estuarine hydrodynamics and/or the modest sample size. The SPM fractions of AA(TP)s in water (Ф: 7.9–100%) and the sediment sorption coefficients (KOC: 0.01–6.56) both positively correlated with their hydrophobicity as indicated by the octanol-water partition coefficient (KOW). Moreover, risk quotients implied moderate to high aquatic toxicity posed by several AA(TP)s at certain YRE sites. The estimated total annual fluxes of our analytes transported via water and sediments towards the East China Sea were 5.90–365.5 tons and 4.23–1,100 kg, respectively. This work provides a systematic investigation of multi-media processes and ecological risks of AA(TP)s in a highly-urbanized estuary, contributing to holistic comprehension of these emerging contaminants in estuarine environments.

Organic fungicides and diphenylamine shift microbiomes of ‘Fuji’ apples during storage

The native microbiome plays an important role in biocontrol efficacy, but less is known about how the microbiome responds to conventional and organic natural product fungicides. This study investigated the effects of the conventional fungicide fludioxonil and the organic fungicide natamycin, with and without the superficial scald inhibitor diphenylamine (DPA) on the microbiomes of ‘Fuji’ apples from 1 to 28 d of storage at 0.5 °C plus 7 d at 20 °C. We hypothesized that fungicide applications would shift the microbiome, with a more pronounced effect from natamycin due to the target specificity of fludioxonil. We also predicted that the antioxidant properties of DPA would shift both bacterial and fungal microbiomes. We found that natamycin resulted in modest fungal shifts and fludioxonil resulted in no observed shifts, while DPA strongly affected the fungal microbiome over time. Chemical treatment was not a predictor of bacterial microbiome variation, but bacterial communities shifted throughout storage. However, many of the trends that occurred during storage were reversed during the 7-d shelf life period at 20 °C after storage. Time in cold storage decreased the relative abundance of Pseudomonas, while DPA application reduced the relative abundance of Aureobasidium, both notable biocontrol genera. These results highlight how chemical applications such as DPA may have unintended effects on beneficial microbes that protect fruit from pathogen infection.

Exploring the anti-diabetic activity of benzimidazole containing Schiff base derivatives: In vitro α-amylase, α-glucosidase inhibitions and in silico studies

The current study explores the anti-diabetic potential of some Schiff bases containing benzimidazole scaffold. These derivative were synthesized by refluxing sodium metabisulfite with ethyl 2-(2-ethoxy-6-formylphenoxy)acetate followed by the addition of ortho phenylene diamine in DMF solvent to get the benzimidazole which was further refluxed in hydrazine hydrate to obtain the hydrazide. Finally various substituted benzaldehydes were treated with the desired hydrazide using a catalytic quantity of acetic acid to obtain the hydrazone Schiff bases. These compounds were evaluated for their ability to inhibit α-amylase and α-glucosidase inhibitory potentials. Among them, six derivatives including 2g, 2h, 2q, 2p, 2i, and 2m displayed noteworthy inhibitory activities against α-amylase (IC50 = 2.15 ± 0.17 µM to 15.18 ± 3.29 µM ) and α-glucosidase (IC50 = 4.21 ± 0.78 to 16.10 ± 0.52 µM) superior than the standard acarbose, while the remaining compounds showed significant to less inhibitory activities. By clarifying the mechanisms of interaction between the chemicals and amino acid residues, the molecular docking analysis attempted to shed light on the binding modalities of these molecules. The reactivity indices of these compounds were calculated using the Density Functional Theory (TD-DFT) approach, employing the B3LYP-d energy function and lacvp**(d,p) basis set for calculations. Schiff base derivatives based on benzimidazole, especially compounds 2h and 2g, exhibited lower electrophilicity and higher bioactivity compared to their counterparts 2i and 2m.

An investigation of the enzymatic oligomerization of nitro-substituted phenylene diamine: Thermal and fluorescence properties

2-nitro-p-phenylenediamine, an aromatic diamine, was studied for its oxidative oligomerization with H2O2 using enzyme-catalyzed oligomer synthesis. Characterization of molecular structures was performed utilizing ultraviolet-visible (UV-Vis) spectrophotometer, Fourier-transform infrared spectroscopy (FT-IR), and nuclear magnetic resonance (NMR) techniques, identifying phenazine-bridged oligomer resulting from the enzymatic oligomerization process. Based on the results of gel permeation chromatography (GPC) analysis, the synthesized compound was identified as being in an oligomeric form. Conversely, the number of repeating units, as determined by Mw, was found to be 28. The solvent effect on the optical features of the synthesized oligomer in polar solvents was analyzed. The degradation of phenazine-type structures in the oligomer occurred at higher temperatures than that of the monomer. Under visible light excitation, the oligomer exhibited green light emission with a quantum yield (QY) of 6.2% in N,N-dimethylformamide (DMF). 2-nitro-p-phenylenediamine was readily oxidized into an oligomer with ortho-coupled constitutional units, having a lower electrochemical band gap than the monomer, via the enzymatic oligomerization route. Scanning electron microscopy revealed that enzyme-catalyzed oxidation of monomers exhibited a spongy morphology with some pores

6-Methyl-5-hepten-2-one promotes programmed cell death during superficial scald development in pear

Plants possess the ability to induce programmed cell death (PCD) in response to abiotic and biotic stresses; nevertheless, the evidence on PCD initiation during pear scald development and the involvement of the scald trigger 6-methyl-5-hepten-2-one (MHO) in this process is rudimentary. Pyrus bretschneideri Rehd. cv. ‘Dangshansuli’ pear was used to validate such hypothesis. The results showed that superficial scald occurred after 120-d chilling exposure, which accompanied by typical PCD-associated morphological alterations, such as plasmolysis, cell shrinkage, cytosolic and nuclear condensation, vacuolar collapse, tonoplast disruption, subcellular organelle swelling, and DNA fragmentation. These symptoms were aggravated after MHO fumigation but alleviated by diphenylamine (DPA) dipping. Through transcriptome assay, 24 out of 146 PCD-related genes, which were transcribed during cold storage, were identified as the key candidate members responsible for these cellular biological alternations upon scald development. Among these, PbrCNGC1, PbrGnai1, PbrACD6, and PbrSOBIR1 were implicated in the MHO signaling pathway. Additionally, PbrWRKY2, 34 and 39 could bind to the W-box element in the promoter of PbrGnai1 or PbrSOBIR1 and activate their transcription, as confirmed by dual-luciferase, yeast one-hybrid, and transient overexpression assays. Hence, our study confirms the PCD initiation during scald development and explores the critical role of MHO in this process.

CZTS/phenylenediamine isomer nanocomposite electrodes for supercapacitor applications

This study delves into the potential of Cu2ZnSnS4 (CZTS) and its phenylenediamine (PDA) derivative-modified nanocomposites as eco-friendly electrodes in supercapacitors, intending to enhance capacitance values in energy storage systems. By integrating ortho (o-PDA), meta (m-PDA), and para (p-PDA) isomers into the CZTS framework, we have observed notable improvements in their electrochemical behavior. The physically bonded CZTS/p-PDA nanocomposites exhibited superior performance, achieving a specific capacitance of 424.6 F/g at a current density of 0.1 A/g and maintaining 95.5 % of this capacitance after 10,000 cycles, indicating excellent cyclic stability. Our research highlights the influence of PDA derivatives on the morphological, structural, and electrochemical characteristics of CZTS nanomaterials. These insights contribute to developing cost-effective, high-performing, and stable composite electrode materials for next-generation energy storage solutions. This work offers a significant step forward in identifying novel and sustainable nanomaterials for energy applications.

High‐Lying Triplet Excitons Utilization of Silole Derivatives Enables their Efficiency Breakthrough in OLEDs

AbstractSiloles are routinely studied in the application of organic light‐emitting diodes (OLEDs) due to their high performances of solid‐state fluorescence property and carrier mobility. The structures of siloles used in electroluminescence device reported so far can only utilize singlet excitons, limiting the device efficiency and commercialization. Seeking to build appliable molecular structures to achieve triplet excitons utilization in silole‐core emitters, two derivatives are designed, Silole‐1DPA‐TRZ and Silole‐1Cz‐TRZ, in which electron acceptor of triazine (TRZ) together with electron donors of diphenylamine (DPA) and carbazole (Cz) modified at 1‐position of silole unit form silole‐D‐A structures. This special molecular design, for the first time, enables triplet excitons harvest via high‐lying reverse intersystem crossing (hRISC) process in silole derivatives with hybridized local and charge‐transfer (HLCT) characteristics. Experimental and theoretical studies show that relative to a stronger charge transfer state of Silole‐1Cz‐TRZ, a more equal local excitation/charge transfer distribution in the HLCT state of Silole‐1DPA‐TRZ is realized, making its application in silole‐based OLED with an efficiency breakthrough of ≈9.1% maximum external quantum efficiency (EQEmax).

Widespread Antioxidants during Storm Events Could Serve as Precursors of Regulated, Priority, and New Disinfection Byproducts.

Widely used antioxidants can enter the environment via urban stormwater systems and form disinfection byproducts (DBPs) during chlorination in downstream drinking water processes. Herein, we comprehensively investigated the occurrence of 39 antioxidants from stormwater runoff to surface water. After a storm event, the concentrations of the antioxidants in surface water increased by 1.4-fold from 102-110 ng/L to 128-139 ng/L. Widespread antioxidants during the stormwater event could transform into toxic DBPs during disinfection. Moreover, the yields of trihalomethanes, haloacetaldehydes, haloacetonitriles (HANs), and halonitromethanes during the chlorination of widely used antioxidants considerably increased with an increasing chlorine dose and contact time. Specifically, the yields of dichloroacetonitrile during the chlorination of diphenylamine (DPA) and N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine (6PPD) were higher than those of most reported amino acid precursors, indicating that DPA and 6PPD might be important precursors of HANs. Exploring the intermediates using GC × GC-time-of-flight high-resolution mass spectrometry helped reveal potential pathways from DPA to HANs, whose formation could be attributed to the intermediate carbazole and indole moieties detected in this study. This study provides insights into the transport and transformation of commonly used antioxidants in a water environment and during water treatment processes, highlighting the potential risks of anthropogenic pollutants from a DBP perspective.

Multi-approach synthesis of functionalized graphene oxide as reinforcement for polyethylene: Make a strong interaction

Nanoparticles need to be well dispersed in a polymer matrix to employ their advantages. Their agglomeration may cause defects and stress concentrations, deteriorating the final properties of polymer/graphene nanocomposite. Here graphene oxide (GO) was functionalized in several ways to improve its interaction with polyethylene and dispersion. Polyethylene-grafted maleic anhydride (PE-g-MA) with strong polar groups was used as the matrix to consider a high potential of enhanced interaction with the GO nanoparticles and therefore obtain a high-performance polyolefin composite. First, GO was produced by modified Hammer’s method from graphite. The GO was aminated by phenylene diamine and named FGO. Also GO was reduced chemically to obtain CRGO and thermally to obtain TRGO and then the recent ones were amino functionalized, named FCRGO and FTRGO, respectively. In another route GO was first amino functionalized and then was reduced chemically and named FCRGO+. The synthesized nanoparticles were characterized by visual tests, FTIR, XRD, SEM, and TGA analysis. Subsequently, the study investigates the fabrication of nanocomposites using these nanoparticles at 2 wt% in the PE-g-MA matrix by solution-casting method. The nanocomposites were characterized by optical microscopy, tensile and rheometric tests, FTIR, DSC, and SEM analysis. Based on the results, FCRGO+ was identified as the optimum nanoparticle having better dispersion, improved interfacial interaction, and stronger mechanical properties. The GO functionalized nanocomposites showed up to 36% in tensile modulus, 56% in tensile strength and 70% in elongation at break as compared to those of GO nanocomposites without functionalization of GO.