Aniline Group Research Articles

Stepwise One‐Shot Borylation Reactions for Intersecting DABNA Substructures Exhibiting Bright Yellow‐Green Electroluminescence with EQE Beyond 40 % and Mild Roll‐Off

AbstractBoron/nitrogen (B/N)‐doped polycyclic aromatic hydrocarbons (PAHs) with the multiple resonance (MR) effect are promising for organic light‐emitting diodes (OLEDs) because of their narrowband emission and thermally activated delayed fluorescence (TADF) characteristics. Nevertheless, exploring the variety of such emitters is challenging because of the tricky and limited synthetic protocols. Herein, we designed a novel B/N‐doped PAH, L–DABNA‐1, whose backbone (L–DABNA) could not be achieved via conventional routes (e.g., one‐pot borylation or one‐shot borylation). We successfully synthesized it through stepwise one‐shot borylations with precisely introducing decorations. The unique MR backbone with intersecting DABNA substructures sharing an aniline group, avoiding any para‐N‐π‐B motif, allows L–DABNA‐1 to maintain narrowband TADF emission while significantly redshifting to the yellow‐green region with a reverse intersystem crossing rate (kRISC) of 1.28×105 s−1. An L–DABNA‐1‐based OLED device achieved a maximum external quantum efficiency (EQE) of over 40 % and maintained a high EQE of 36.3 % at 1000 cd m−2, with a current efficiency reaching ~170 cd A−1. This work not only demonstrated the great potential of stepwise borylations in synthesizing B/N‐doped PAH backbones, expanding their chemical space, but also provided a promising pathway for exploring MR‐TADF emitters at longer wavelengths.

Conductive single enzyme nanocomposites prepared by in-situ growth of nanoscale polyaniline for high performance enzymatic bioelectrode

Enzyme-based electrochemical biosensors hold great promise for applications in health/disease monitoring, drug discovery, and environmental monitoring. However, inherently non-conductive nature of proteinaceous enzymes often hampers effective electron transfer at enzyme-electrode interface, limiting biosensor performance of enzyme bioelectrodes. To address this problem, we present an approach to synthesize polyaniline (PAN)-based conductive single enzyme nanocomposites of glucose oxidase (GOx) (denoted as PAN-GOx). To prevent multimerization of enzymes during nanocomposite synthesis and enable single enzyme wrapping, we activate GOx surface with phenylamine groups based on the programmed diffusion of reactants in the reaction solution. Subsequent in-situ polymerization enables the synthesis of nanoscale conductive PAN layer (∼2.7 nm thickness) grafted from individual GOx molecule. PAN-GOx retains 83% and 74% of its specific activity and catalytic efficiency, respectively, compared to free GOx, while demonstrating a ∼500% improved conductivity. Furthermore, PAN-GOx-based glucose biosensors show an approximately 16- and 3-fold higher sensitivity compared to biosensors prepared by using free GOx and a mixture of PAN and GOx, respectively. This study provides a facile method to fabricate conductive single enzyme nanocomposites with enhanced electron transfer, which can potentially be further modified and/or compounded with conductive materials for demonstrating high performance enzymatic bioelectrodes.

Improved Sensitivity in a Modified Berkeley Red Sensor of Transmembrane Potential.

Voltage imaging is an important complement to traditional methods for probing cellular physiology, such as electrode-based patch clamp techniques. Unlike the related Ca2+ imaging, voltage imaging provides a direct visualization of bioelectricity changes. We have been exploring the use of sulfonated silicon rhodamine dyes (Berkeley Red Sensor of Transmembrane potential, BeRST) for voltage imaging. In this study, we explore the effect of converting BeRST to diEt BeRST, by replacing the dimethyl aniline of BeRST with a diethyl aniline group. The new dye, diEt BeRST, has a voltage sensitivity of 40% ΔF/F per 100 mV, a 33% increase compared to the original BeRST dye, which has a sensitivity of 30% ΔF/F per 100 mV. In neurons, the cellular brightness of diEt BeRST is about 20% as bright as that of BeRST, which may be due to the lower solubility of diEt BeRST (300 μM) compared to that of BeRST (800 μM). Despite this lower cellular brightness, diEt BeRST is able to record spontaneous and evoked action potentials from multiple neurons simultaneously and in single trials. Far-red excitation and emission profiles enable diEt BeRST to be used alongside existing fluorescent indicators of cellular physiology, like Ca2+-sensitive Oregon Green BAPTA. In hippocampal neurons, simultaneous voltage and Ca2+ imaging reveals neuronal spiking patterns and frequencies that cannot be resolved with traditional Ca2+ imaging methods. This study represents a first step toward describing the structural features that define voltage sensitivity and brightness in silicon rhodamine-based BeRST indicators.

Visualizing dynamic alterations of vitreous viscosity during elevated intraocular pressure in glaucoma with a Near-infrared/Magnetic resonance imaging dual-modal nanoprobe

Glaucoma is a chronic progressive disease leading to irreversible visual impairment and blindness. High intraocular pressure (IOP) resulting from abnormally high outflow resistance is a major risk factor for glaucoma development, however, it is unclear how IOP elevation influences the structure and function of the retina and the optic nerve via vitreous humor located between the lens and retina in the eye. To understand vitreous biomechanical and stimulus response toward IOP elevation, we developed a novel near-infrared (NIR)/MRI dual-modal nanoprobe, DTA/P-NCA/17F@Co, which is composed of N, N-dimethyl-4(thien-2-yl)-aniline group (DTA) as NIR fluorophore and the fluorine-based polyamino acid cobalt nanoparticles (P-NCA/17F@Co) as T2 contrast agent. These nanoprobes exhibit good biocompatibility, low surface energy characteristics, and viscosity-responsive NIR emission and T2 relaxation values. The intrinsic viscosity-sensitivemechanismof nanoprobes was ascribed to constrained molecular motion in high-viscosity vitreous chamber, which causes enhanced fluorescence emission and shortened T2 relaxation times. By using its ability for dual-modal visualization of viscosity, we achieved non-invasive in vivo monitoring the changes in vitreous viscosity during elevated IOP in a glaucoma rat model. In vivo experiments validated that vitreous viscosity is very strongly correlated with IOP elevation induced by glaucoma, much earlier than structural and functional change in the retina. Our findings revealed that IOP elevation induced the increase of vitreous viscosity, indicating that monitoring vitreous viscosity is key to the glaucoma model. This study not only provides versatile nanoprobes for dual-modal visualization of biomechanical properties of the vitreous humor in its native environment, but also shows great potential in the early diagnosis of glaucoma.

Hybrid Aromatic Fluoro Amine‐Modified SnO2 Electron Transport Layers in Perovskite Solar Cells for Enhanced Efficiency and Stability

SnO2 is a widely used electron‐transporting layer (ETL) in perovskite solar cells. Despite the high compatibility with the perovskite absorber layers, the presence of traps at the perovskite|SnO2 interface results in performance losses; hence, their modification to improve the performance and stability of perovskite solar cells (PSCs) is therefore important. Herein, the SnO2 ETL is enhanced by incorporating a bifunctional aromatic amino fluorine molecule into the SnO2 precursor solution. The fluorine molecule is found to partially substitute the Sn and alter the energy levels while the aniline group aids in regulating the nucleation/growth rate of the perovskite crystalline films. Herein, a hole transporting material‐free carbon‐based PSCs (CPSCs) is fabricated. It is found that perovskite absorber layers deposited on these modified SnO2 hybrid layers have higher optoelectronic quality, resulting in enhanced photovoltaic performance, device stability, and reduced hysteresis in CPSCs. Devices made with the modified hybrid SnO2 layers exhibit power conversion efficiencies of 15.6% significantly better than unmodified SnO2 with 13.5%. CPSCs with these modified SnO2 films also exhibit remarkable retention of 88.7% of their initial PCE for a shelf‐life period (ISOS‐D1I) exceeding 1200 h.

Stepwise One-Shot Borylation Reactions for Intersecting DABNA Substructures Exhibiting Bright Yellow‒Green Electroluminescence with EQE Beyond 40% and Mild Roll-Off.

Boron/nitrogen (B/N)-doped polycyclic aromatic hydrocarbons (PAHs) with the multiple resonance (MR) effect are promising for organic light-emitting diodes (OLEDs) because of their narrowband emission and thermally activated delayed fluorescence (TADF) characteristics. Nevertheless, exploring the variety of such emitters is challenging because of the tricky and limited synthetic protocols. Herein, we designed a novel B/N-doped PAH, L-DABNA-1, whose backbone (L-DABNA) could not be achieved via conventional routes (e.g., one-pot borylation or one-shot borylation). We successfully synthesized it through stepwise one-shot borylations with precisely introducing decorations. The unique MR backbone with intersecting DABNA substructures sharing an aniline group, avoiding any para-N-π-B motif, allows L-DABNA-1 to maintain narrowband TADF emission while significantly redshifting to the yellow-green region with a reverse intersystem crossing rate (kRISC) of 1.28 × 105 s-1. An L-DABNA-1-based OLED device achieved a maximum external quantum efficiency (EQE) of over 40% and maintained a high EQE of 36.3% at 1000 cd m-2, with a current efficiency reaching ~170 cd A-1. This work not only demonstrated the great potential of stepwise borylations in synthesizing B/N-doped PAH backbones, expanding their chemical space, but also provided a promising pathway for exploring MR-TADF emitters at longer wavelengths.

Cu-Catalyzed Amination of Base-Sensitive Aryl Bromides and the Chemoselective N- and O-Arylation of Amino Alcohols.

We report a general and functional-group-tolerant method for the Cu-catalyzed amination of base-sensitive aryl bromides including substrates possessing acidic functional groups and small five-membered heteroarenes. The results presented herein substantially expand the scope of Cu-catalyzed C-N coupling reactions. The combination of L8, an anionic N1,N2-diarylbenzene-1,2-diamine ligand, along with the mild base NaOTMS leads to the formation of a stable yet reactive catalyst that resists deactivation from coordination to heterocycles or charged intermediates. This system enables the use of low catalyst and ligand loadings. Exploiting the differences in nucleophile deprotonation in C-O and C-N coupling reactions catalyzed by Cu·L8 we developed a method to chemoselectively N- and O-arylate a variety of amino alcohol substrates. Employing NaOt-Bu as the base resulted exclusively in C-O coupling when the amino alcohols featured primary alcohols and more hindered amines or aniline groups. Utilizing NaOTMS enabled the ability to override the steric-based selectivity of these reactions completely and exclusively promoted C-N coupling regardless of the structure of the amino alcohol. The ability to invert the observed chemoselectivity is distinct from previously described methods that require protecting group manipulations or rely entirely on steric effects to control reactivity. These results substantially improve the scope of Cu-catalyzed C-N coupling reactions using N1,N2-diarylbenzene-1,2-diamine ligands and introduce a new chemoselective method to arylate amino alcohols.

Comparison of Vinyldimethylaniline and Indolizine Donor Groups on Si‐Substituted Xanthene Core Shortwave Infrared Fluorophores

AbstractSmall organic molecules absorbing and emitting in the shortwave infrared (SWIR, 1000–2000 nm) region are desirable for biological imaging applications due to low auto‐fluorescence, reduce photon scattering, and good tissue penetration depth of photons which allows for in vivo imaging with high resolution and sensitivity. Si‐substituted xanthene‐based fluorophores with indolizine donors have demonstrated some of the longest wavelengths of absorption and emission from organic dyes. This work seeks to compare an indolizine heterocyclic nitrogen with dimethyl aniline nitrogen donors on otherwise identical Si‐substituted xanthene fluorophores via optical spectroscopy, computational chemistry and electrochemistry. Three donors are compared including an indolizine donor, a ubiquitous dimethyl aniline donor, and a vinyl dimethyl aniline group that keeps the number of π‐bonds consistent with indolizine. Significantly higher quantum yields and molar absorptivity are observed in these studies for a dimethylamine‐based donor relative to a simple indolizine donor absorbing and emitting at similar wavelengths (~1312 nm emission). Substantially longer wavelengths are obtainable by appending aniline‐based groups to the indolizine donor (~1700 nm) indicating longer wavelengths can be accessed with indolizine donors while stronger emitters can be accessed with anilines in place of indolizine.

Ab initio exploration of modified carbon nanotubes as potential corrosion inhibitors

In order to develop novel unexplored potential corrosion inhibitors, covalently modified single-walled carbon nanotubes (SWCNT) via benzoic (–PhCOOH) and aniline (–PhNH2) groups are being investigated as corrosion inhibitors for the first time. Utilizing a comprehensive approach, this study employed density functional theory (DFT), Monte Carlo (MC), and molecular dynamics simulations (MD) to assess the adsorption behavior of modified nanotubes as corrosion inhibitors on the Cu(111) surface within a simulated aqueous HCl corrosion medium. The results provided molecular information on the adsorption capability, geometry adsorption centers, and adsorption energies (Eads) of carbon nanotubes on the surface of Cu(111). The adsorption energy values unveiled robust interactions between SWCNT–PhCOOH and SWCNT–PhNH2 inhibitors and the Cu(111) surface, suggesting a highly effective corrosion protection mechanism. The calculated Eads values exhibited notable ranges, spanning from –260.82 to –308.18 kcal/mol for SWCNT–PhCOOH and –220.92 to –261.01 kcal/mol for SWCNT–PhNH2 with the maximum probability values, representing the most favorable adsorption scenarios, determined to be –292.96 and –229.39 kcal/mol, respectively. A key insight from Monte Carlo simulations underscored the inherent spontaneity of the adsorption process, corroborated by the consistently negative Eads values. These findings collectively underscore the substantial affinity of the inhibitors to the copper surface, contributing to a deeper comprehension of their corrosion inhibition capabilities.

Construction and evaluation of near-infrared fluorescent probes for imaging lipid droplet and lysosomal viscosity

Microenvironmental viscosity is a crucial parameter for biological systems, and its abnormal fluctuations are closely associated with various functional disorders and diseases. However, it is still important and urgent to develop improved near-infrared fluorescent probes for micro-viscosity with dual-organelle targeting properties, low background noise, and high sensitivity. Herein, two BODIPY-based small-molecule fluorescent probes were designed and synthesized, which were explored for their viscosity- and polarity-responsive properties, and were further applied to imaging sub-cellular viscosity in living cells. Interestingly, BSZ-Ph and BSZ-R displayed near-infrared fluorescence (more than 650 nm) and were sensitive to environmental viscosity and polarity due to the introduction of a benzothiazole at the 2-position and electron-rich aniline groups at the 5-position of the BODIPY core, respectively. The fluorescence intensity increased exponentially with the viscosity changes. Furthermore, the probe BSZ-Ph could successfully target lipid droplets and image cellular viscosity changes by treating lipopolysaccharides (LPS) and nystatin. Comparatively, the probe BSZ-R could successfully target the dual organelles of lipid droplets and lysosomes and image cellular viscosity changes by treating LPS and monensin. Therefore, in this work, we reported two new BODIPY-based near-infrared fluorescent probes, BSZ-Ph and BSZ-R, for cellular viscosity imaging, which could target lipid droplets and the dual organelles of lysosomes and lipid droplets, respectively. The study could provide a reference for the future development of fluorescent probes for viscosity in lipid droplets and lysosomes.

Improved thermoelectric properties by copolymerization of conducting with insulating monomers on carbon nanotubes

In the present work, development of carbon nanotube (CNT)/poly(conducting-co-insulating monomer) structures was proposed to improve the thermoelectric (TE) performance in CNT/polyaniline (PANI) composites. To check the validity of this idea, we prepared multiwalled carbon nanotube (MWNT)/poly(aniline-co-acrylonitrile) composites by in-situ inverted emulsion copolymerization, and applied secondary doping with camphorsulfonic acid in m-cresol medium prior to the investigation of TE properties. The samples were characterized by FT-IR, UV–Vis, 1H NMR, DSC, GPC, CHNS elemental analysis, intrinsic viscosity, SEM, XRD, electrical resistance, Seebeck coefficient, thickness, and Hall measurements. We report that nitrile groups were hydrolyzed during the polymerization reactions to provide a polymer structure exhibiting aniline, acrylamide, acrylic acid, and glutarimide groups. Further, the poly(aniline-co-acrylonitrile) that prepared in the present work were random copolymers. Importantly, we found that 30 % MWNT/70 % poly(90ANI-co-10AN) composite exhibited a 63 % higher power factor (PF) of 5.48 μW/mK2 (σ: 225 S/cm, S: 15.6 μV/K) at 35 °C than that of 30 % MWNT/70 % PANI, which exhibited a PF of about 3.37 μW/mK2 (σ: 238 S/cm, S: 11.9 μV/K). This was ascribed to the decrease of carrier concentration together with the increase of carrier mobility in the 30 % MWNT/70 % poly(90ANI-co-10AN) composite as compared to the 30 % MWNT/70 % PANI.

Tribological behaviour of surface modified carbon-fibre-reinforced polyphenylene sulphide under dry condition

This study presents a direct electrochemical modification technique for incorporating two specific small molecules, phenol, and aniline into carbon fibre (CF) surface. These molecules have a strong hydrogen bonding for polyphenylene sulphide (PPS) and are intended to improve the friction and wear properties of PPS/CF composites. The tribological properties of PPS/CF composites were evaluated using a pin-on-disc. To get a more thorough comprehension of the working conditions of PPS/CF composites, a comparative examination of the composites' tribological characteristics was carried out by modifying the nature of the opposing surface while keeping the sliding speed of the applied force consistent. The results showed that the addition of 10 mM phenol to carbon fibre results in a significant reduction in the coefficient of friction (COF) compared to carbon fibre treated with 50 mM phenol and 6 mM aniline when in contact with a steel counter-face. When sliding against a polymer counter-face, the composites experienced a reduction in the COF due to the formation of a transfer film rich in PPS. Introducing aniline groups to the fibre surface reduced the wear rate by 57.5% to 46% with applied forces of 25 N compared to PPS and unmodified PPS/CF when sliding against the polymer counter-face. This study thoroughly discusses the synergistic process of chemical modification on the tribological performance of PPS/CF. It also analyses the surface microstructures of the worn surfaces of the composites. This study has the potential to provide new insights into the design and development of CF/polymer composites with enhanced friction and wear properties.

Enzyme-induced reactive oxygen species trigger oxidative degradation of sulfamethoxazole within a methanotrophic biofilm

Although microorganisms carrying copper-containing membrane-bound monooxygenase (CuMMOs), such as particulate methane monooxygenase (pMMO) and ammonia monooxygenase (AMO), have been extensively documented for their capability to degrade organic micropollutants (OMPs), the underlying reactive mechanism remains elusive. In this study, we for the first time demonstrate biogenic reactive oxygen species (ROS) play important roles in the degradation of sulfamethoxazole (SMX), a representative OMP, within a methane-fed biofilm. Highly-efficient and consistent SMX biodegradation was achieved in a CH4-based membrane biofilm reactor (MBfR), manifesting a remarkable SMX removal rate of 1210.6 ± 39.0 μg·L−1·d−1. Enzyme inhibition and ROS clearance experiments confirmed the significant contribution of ROS, which were generated through the catalytic reaction of pMMO and AMO enzymes, in facilitating SMX degradation. Through a combination of density functional theory (DFT) calculations, electron paramagnetic resonance (EPR) analysis, and transformation product detection, we elucidated that the ROS primarily targeted the aniline group in the SMX molecule, inducing the formation of aromatic radicals and its progressive mineralization. In contrast, the isoxazole-ring was not susceptible to electrophilic ROS attacks, leading to accumulation of 3-amino-5-methylisoxazole (3A5MI). Furthermore, microbiological analysis suggested Methylosarcina (a methanotroph) and Candidatus Nitrosotenuis (an ammonia-oxidizing archaea) collaborated as the SMX degraders, who carried highly conserved and expressed CuMMOs (pMMO and AMO) for ROS generation, thereby triggering the oxidative degradation of SMX. This study deciphers SMX biodegradation through a fresh perspective of free radical chemistry, and concurrently providing a theoretical framework for the advancement of environmental biotechnologies aimed at OMP removal.

Thermal stability and electrical properties of polyaniline/waterborne polyurethane composites by using in-situ polymerization

The thermal stability and processing stability of polyaniline (PANI) as an electrode material is a spot widely concerned. This paper uses water-based polyurethane (WPU) as the polymeric substrate and uses in-situ polymerization to manufacture the PANI/WPU composite electrode material. Molecular structure, morphology of electrodes, thermal stability and polaron/dipole transition of PANI/WPU composites were observed. The results showed that the NH- group of aniline interacted with the NHCOO- group of WPU, and the PANI/WPU composite was prepared successfully. The PANI composite exhibits excellent electrical properties when its cyclic voltammetry curve is a nice rectangle with a ratio of 1:0.3 for WPU to aniline. When the current density is 1 A/g, the specific capacitance of the S3 sample reaches 473.3 F/g, which is much better than pure PANI. Compared with other composite materials, PANI/WPU has higher conductivity and good thermal stability. At the same time, PANI/WPU exhibits excellent chemical stability when used as an electrode material for concentrated cells. By solving the processing performance and thermal stability of PANI, it expands its applications in organic electronics.

Effect of electronegative atoms on [formula omitted] – [formula omitted] stacking and hydrogen bonding behavior in simple aromatic molecules — An Ab initio MD study

Ab initio molecular dynamics studies have been performed on fluorobenzene, phenol, and aniline, which have the three most electronegative atoms, fluorine, oxygen, and nitrogen, respectively. Radial distribution functions show strong hydrogen bonding in the phenolic –OH group, whereas it is less prominent in the –NH2 group of aniline. Fluorobenzene does not show strong hydrogen bonds as no solvation shell is found between the fluorine atom and different aromatic hydrogens of the molecule. Spatial distribution functions show that the nitrogen atom of aniline interacts with the aromatic plane, the oxygen atom of phenol is concentrated near the –OH group and fluorobenzene’s fluorine atom interacts with the para hydrogen. Liquid phase dimer structures of these systems reveal that perpendicular orientation (Y-shaped) is preferred over parallel ones. Almost half of the total dimer population tends to prefer 90∘±30° angle. H-bond analyses show that fluorobenzene has the longest mean H-bond lifetime for the H-bond between the aromatic hydrogens and the fluorine atoms, whereas the aniline has the least. The mean lifetime between aromatic hydrogens and electronegative atoms increases steadily from aniline to fluorobenzene. Phenolic –OH and amino –NH2 groups show considerably longer mean H-bond lifetime than the aromatic hydrogens. Gas-phase binding energies obtained from quantum chemical calculations show that aniline and phenol dimers have higher binding energy values than the fluorobenzene dimer. Only the phenol dimer shows a perpendicular structure as a stable one, while aniline and fluorobenzene prefer the parallel orientation.

Approach to Significantly Enhancing the Electrochromic Performance of PANi by In Situ Electrodeposition of the PANi@MXene Composite Film.

Electrochromic materials (ECMs) are capable of reversibly adjusting their transmittance or reflectance properties in response to changes in the external biasing voltages. In this study, we enhanced the electrochromic and electrochemical properties of polyaniline (PANi) effectively through the incorporation of MXene Ti2CTx using an in situ composite strategy. This improvement in the electrochromic and electrochemical properties observed can be attributed to the intermolecular forces between the aniline group of PANi and the terminal groups of MXene Ti2CTx sheets. The presence of hydrogen bonds between the PANi monomers and the MXene sheets was confirmed through theoretical calculations and photoluminescence results, which effectively improved the composite interfaces. Additionally, the PANi@MXene composite films were successfully prepared through a simple one-step in situ polymerization process, as verified by SEM and XPS characterization. The electrochemical studies revealed enhanced electronic conductivity, a high ion diffusion coefficient, and a narrow energy redox gap, all contributing to the excellent electrochemical properties observed. Overall, our results demonstrate that the MXene Ti2CTx composition effectively enhances the electrochromic performance of PANi. The PANi@MXene composite films exhibited a high optical modulation range, rapid switching response time, good thermal radiation regulation, and excellent operational stability. This composite strategy significantly improves the performance and practical applicability of ECMs.

Functional-Group-Tolerant Pd-Catalyzed Carbonylative Negishi Coupling with Aryl Iodides.

A chemoselective Pd-mediated carbonylative Negishi-type catalytic protocol for the synthesis of (hetero)aryl ketones is reported. The protocol employs the PEPPSI-IPr precatalyst and CO gas at atmospheric pressure (balloon) to foster the carbonylative coupling between diverse C(sp3)-hybridized organozinc reagents and a broad range of aryl iodides, including substrates carrying aldehyde, aniline, phenol, or carboxylic acid groups, and heteroaryls.

Facile surface amination strategy of PIM-1 based membranes for efficient CO2 capture

Carbon dioxide capture by membrane method is considered an important way to solve global warming, and it has become one of the most active research fields at present. Herein, a facile surface amination strategy by diazonium-induced anchoring process (DIAP) was introduced in the modification of polymers of intrinsic microporosity-1 (PIM-1) based membranes for efficient separation of CO2/N2. According to the detection of the chemical and surface properties, the polyaminophenylene (PAP) layer grafting on the surface could be regulated by simply changing the modification time. The modified membranes show significant increase in the CO2/N2 selectivity, which is attributed to the enhanced solubility-selectivity of the amino-rich surface. However, the attachment of the noncovalently grafted aniline groups increases the mass transfer resistance and surface non-uniformity, thereby significantly damaging the permeability of the membranes. Therefore, methanol is employed to clean the redundant PAP. As a result, the permeability of the membranes after methanol post-treatment increases evidently, while the membranes maintain good CO2/N2 selectivity. The selectivity of CO2/N2 and the permeability of CO2 are 34.1 and 11421.5 Barrer respectively at the optimal modification condition, which exceeds the upper bound established in 2019. This work will encourage the researchers to pay more attention to surface modification for CO2 capture, which might be relatively easy for industrial scale-up.

In vitro and in vivo toxicity of carbon dots with different chemical compositions

Carbon dots (CDs) are easy-obtained nanoparticles with wide range of biological activity; however, their toxicity after prolonged exposure is poorly investigated. So, in vitro and in vivo toxicity of CDs with the surfaces enriched with hydroxylated hydrocarbon chains and methylene groups (CD_GE), carboxyl and phenol groups accompanied with nitrogen (CD_3011), trifluoromethyl (CDF19) or toluidine and aniline groups (CDN19) were aimed to be discovered. CDs’ in vitro toxicity was assessed on A549 cells (real-time cell analysis of impedance, fluorescence microscopy) after 24 h of incubation, and we observed no changes in cell viability and morphology. CDs’ in vivo toxicity was assessed on C57Bl6 mice after multiple dosages (5 mg/kg subcutaneously) for 14 days. Lethality (up to 50%) was observed in CDN19 and CD_3011 groups on different days of dosing, accompanied by toxicity signs in case of CD_3011. There were no changes in serum biochemical parameters except Urea (increased in CDF19 and CD_3011 groups), nor substantial kidney, liver, and spleen injuries. The most impactful for all organs were also CD_3011 and CDF19, causing renal tubule injury and liver blood supply violation. Thus, CDs with a surface enriched with oxygen- and nitrogen-containing functional groups might be toxic after multiple everyday dosing, without, however, significant damages of internal organs in survived animals.

The role of reactive phosphate species in the abatement of micropollutants by activated peroxymonosulfate in the treatment of phosphate-rich wastewater.

This study investigated the mechanisms of forming reactive species to degrade micropollutants through the activation of peroxymonosulfate (PMS) by phosphate, a prevalent ion in wastewater. Considering the density functional theory results, the formation of hydrogen bonds between phosphate and PMS molecules might be the crucial step in the overall reactions, which prefers producing ⋅OH and reactive phosphate species (RPS, namely H2PO4⋅, HPO4⋅-, and PO4⋅2-) to yielding SO4⋅-. Besides, in the phosphate (5mM)/PMS system at pH=8, HPO4⋅- was modeled to be the dominant radical with a steady-state concentration of 3.6×10-12M, which was 666 and 773 times higher than those of ⋅OH and SO4⋅-. The contributions of 1O2, ⋅OH, SO4⋅-, and RPS to the micropollutant decomposition in phosphate/PMS were studied, and RPS were found to be selective for micropollutants with electron-donating moieties (such as phenolic and aniline groups). Additionally, the degradation pathways of bisphenol A, diclofenac, ibuprofen, and atrazine in phosphate/PMS were proposed according to the detected transformation products. Cytotoxicity analysis was carried out to evaluate the potential environmental impacts resulting from the degradation of micropollutants by phosphate/PMS. This study confirmed the significance of RPS for micropollutant degradation during PMS-based treatment in phosphate-rich scenarios.