Organic redox-active molecules are promising catholyte materials for aqueous organic redox flow batteries (AORFBs), yet they often suffer from low solubility and poor cycling stability. Herein, we report a series of water-soluble phenothiazine derivatives functionalized with quaternary ammonium groups. The optimized compound, N,N,N-trimethyl-1-(10H-phenothiazin-10-yl) propan-2-aminium chloride (TMiPrPTCl), exhibits exceptional solubility (2.69 M in water) and a high redox potential (0.902 V vs. SHE). A comparative study of four derivatives reveals that side-chain length and branching critically modulate both solubility and degradation pathways: while three-carbon-linked analogs N,N,N-trimethyl-3-(10H-phenothiazin-10-yl)propan-1-aminium chloride (TMPrPTCl) degrade primarily via irreversible oxidation to sulfoxide, two-carbon-linked species (TMiPrPTCl) undergo additional side-chain cleavage, leading to rapid capacity fade. Although the quaternization strategy successfully achieves record solubility, the electrochemical stability remains a key challenge. Post-cycling analysis confirms the loss of redox activity and the formation of inert products. This work highlights the delicate balance between solubility enhancement and molecular stability, providing clear design guidelines for future phenothiazine-based catholytes.

Cationic surfactants from quaternary ammonium compounds (QACs) are increasingly recognized as relevant micropollutants particularly following their widespread use during and after the COVID-19 pandemic. The new EU Urban Wastewater Treatment Directive (2024/3019) highlights micropollutant removal as a regulatory priority, mandating advanced treatment for their elimination. In this context, this study examined benzalkonium chloride (BAC) retention and membrane response during nanofiltration (NF) and reverse osmosis (RO), across concentrations ranging from monomeric to micellar. RO membranes achieved >97% rejection, whereas NF showed 65-96% removal strongly affected by micelle formation. Flux decline was most pronounced in RO, with relative permeability (J/J0) decreasing to ~0.12 at 1.0 CMC, while NF membranes exhibited better hydraulic stability. Membrane active layer zeta potential measurements confirmed adsorption and charge neutralization, with shifts toward less negative values after BAC exposure. Hermia model analysis revealed that fouling was governed by cake layer formation or pore blocking, depending on membrane type and feed concentration.

CpG oligodeoxynucleotides (CpG ODNs), as nucleic acid adjuvants, effectively stimulate humoral and cellular immune responses. However, their clinical application is limited by drawbacks such as susceptibility to nuclease degradation and high negative charge, which impede cellular uptake. Previously, we have confirmed that polyelectrolyte complex nanoparticles composed of curdlan sulfate (CS) and O-(2-hydroxyl) propyl-3-trimethyl ammonium chitosan chloride (CS/O-HTCC) could encapsulate negatively charged proteins and enhance their cellular internalization. Hence, in this study, CS/O-HTCC/CpG nanoparticles (C/O/CpG NPs) were prepared by electrostatic adsorption of positively charged CS/O-HTCC NPs with negatively charged CpG ODN and the formulation was optimized. Besides, the immunological activities of C/O/CpG NPs were evaluated both in vitro and in vivo. Moreover, their adjuvant properties and antitumor effects were assessed using ovalbumin (OVA) as a model antigen. The results showed that C/O/CpG NPs were uniformly spherical with a particle size and polydispersity index (PDI) of 119.67 ± 9.07 nm and 0.18 ± 0.01, respectively. C/O/CpG NPs stimulated the activation of antigen-presenting cells, induce antigen-specific cellular and humoral immune responses effectively and showed significant anti-tumor activity. In conclusion, C/O/CpG NPs could be considered as a promising class of adjuvants for tumor vaccines.

India's continued reliance on coal for power generation, steel, and cement production results in substantial emissions of fine particulate matter (PM2.5) and associated chemical species, particularly in densely populated industrial and mining regions. Characterizing PM2.5 composition and its sources is critical for accurate exposure assessment and targeted mitigation of environmental and climate impacts. This study investigates the chemical composition of PM2.5 at roadsides and residential sites within a major opencast coal mining region in Western India and attributes its sources using Absolute Principal Component Analysis-Multiple Linear Regression (APCS-MLR). PM2.5 was highest at the mining roadside (546 ± 182 μg m[-3]), city road (363.6 ± 105 μg m[-3]), and residential locations which were located 2 and 5 km from the mine (122 ± 43 μg m[-3] and 116 ± 36 μg m[-3], respectively). Carbonaceous components contributed 10-20 % to PM2.5, with organic carbon (22.82 ± 12.65 μg m[-3]) nearly two-fold higher than elemental carbon (9.68 ± 5.68 μg m[-3]). Ions (20-30 % of PM2.5) were dominated by chloride, sulfate, ammonium, potassium, and nitrate. Crustal metals associated with non-exhaust, coal, and industrial activities were two-fold higher at roadside locations, compared to residential sites. Benzo(a)pyrene dominated the PAHs fraction (19.7 ± 5.2 μg m[-3]), and diagnostic ratios revealed a mix of pyrogenic and petrogenic sources. Major source categories identified were non-exhaust/crustal/industrial (56 %), vehicular and coal-combustion (36 %), and biomass burning/secondary aerosols (7 %). Vehicular fleet characterization showed a predominance of heavy-duty diesel vehicles along mining transport corridors and mixed fleet traffic on the urban road. Overall, the results highlight mining-associated vehicular transport, dust resuspension, secondary aerosols, and regional combustion sources act as key drivers of PM2.5 in this mining region. This underscores the need for targeted, source-specific, and multi-pollutant mitigation strategies that extend beyond conventional dust control in mining-dominated regions.

The crystal structure of 5-amino-levulinic acid hydro-chloride (systematic name: 4-carb-oxy-2-oxobutan-1-aminium chloride), C5H10NO3 +·Cl-, has been solved and refined using synchrotron X-ray powder diffraction data, and optimized using density functional theory (DFT) techniques. The structure is compared to a recent single-crystal determination [Wang et al. (2025 ▸). Z. Kristallogr. New Cryst. Struct. 240, 413-414]. 5-Amino-levulinic acid hydro-chloride crystallizes in the space group Pbca (No. 61), with a = 8.20862 (9), b = 11.22253 (10), c = 16.8595 (2) Å, V = 1553.12 (4) Å3, and Z = 8 at 298 K. The crystal structure consists of layers parallel to the ab plane. The center of the layers contains hydro-philic NH3, Cl, and CO2H groups, and the outer surface of the layers is composed of hydro-phobic CH2 groups. Hydrogen bonds are prominent in the crystal structure. The ammonium group acts as a donor to three chloride anions, and one hydrogen bond is bifurcated to the carbonyl group. Each Cl- anion is an acceptor in three N-H⋯Cl hydrogen bonds, plus one from the carb-oxy-lic acid group. These hydrogen bonds connect the cations and anions into the layers parallel to the ab plane. The powder pattern has been submitted to the Inter-national Centre for Diffraction Data (ICDD) for inclusion in the Powder Diffraction File (PDF).

In this study, the physicochemical characteristics of PM2.5 at three different locations in Indonesia were compared during a short-term sampling period, and their association with respiratory diseases was also investigated by analysing aerosol optical thickness (AOT) data from Himawari satellite observations due to the limitation of the PM2.5 field sampling. Bandung city in West Java province, Serpong in Banten province, and Ogan Komering Ilir in South Sumatra province were selected as the study locations, each with distinct characteristics. PM2.5 sampling was conducted for 24 hours in Bandung (1-7 November 2021), 12 hours in OKI (4-7 October 2021), and also 12 hours in Serpong (25-29 July 2022). Morphology and elemental analysis for PM2.5 particle characterization were conducted by using a Scanning Electron Microscope (SEM) with an Energy Dispersive X-Ray Spectrometer (EDS). The water-soluble ion composition was analysed using Ion Chromatography to determine the anion (sulfate, nitrate, chloride) and cation (potassium, calcium, magnesium, sodium, ammonium) concentrations. To identify the potential source regions contributing to PM2.5 pollution at the sampling site, trajectory analysis using the HySplit model from NOAA was conducted. The average concentration of PM2.5 at Bandung was 87.98 μg/m[3] (24 hours), at OKI was 36.31 μg/m[3] (12 hours), and at Serpong was 23.53 μg/m[3] (12 hours). The morphology analysis revealed spherical, regular, and irregular particles in Bandung, and some soot particles were found in OKI, with a dominance in Serpong. The elements of Mg, Si, S, K, Ca, Cu, and Pb were detected in Bandung, whereas in OKI, the Ca element was not detected. Si, S, Mg, and K were also detected in Serpong. Sulphate, nitrate, and ammonium (SNA) are the most abundant ions found in almost every location. Trajectory analysis revealed that local sources of pollutants dominated Bandung and OKI, while Serpong experienced some long-range transport from other locations.

Vaterite is one of the polymorphs of CaCO3 that has been used as sustainable drug carrier because of tuned sizes, porosity, low production costs, non-toxic and biocompatible/degradable nature. It can also be used as a sacrificial template for hard templating of polymer-based structures such as multilayer microgels. Both vaterites and microgels are highly advantageous offering protection and regulation the release of the drugs, thereby enhancing drug bioavailability. However, loading of hydrophobic drugs in such carriers is still a challenge. In this study, a water-insoluble drug cannabidiol (CBD) was loaded into both vaterite crystals and microgels made of sustainable biopolymers. Surface-supported vaterite crystals were synthesized via direct mixing of CaCl2 and Na2CO3 in water-ethanol mixture (20-70% ethanol). Increase of ethanol content results in the formation of smaller crystals of needle- and cauliflower-like shapes. CBD was loaded into crystals either by co-synthesis or post-loading providing up to ca 4% w/w of CBD. Crystal sizes can easily be varied in the range of microns (here 3-13 μm) and beyond by tweaking the synthesis conditions (e.g. salt stirring time and speed). Microgels were formed by coating of vaterite crystals with five layers of oppositely charged biopolymers and showed excellent stability in ethanol-water mixture. Hydroxypropyl trimethyl ammonium chitosan chloride based microgels were loaded with ca 1% w/w of CBD via adsorption. Mechanism of CBD loading and factors affecting stability of microgels in ethanol-water solutions are discussed in view of dynamics of interpolymer interactions in multilayers. These findings highlight the potential of sustainable hard (vaterite CaCO3) and soft (polymer microgels) structures as a versatile platform for encapsulation of hydrophobic drugs like CBD, offering tuneable systems for drug delivery applications.

Sodium nitrite and ammonium chloride are commonly used thermochemicals in the oil field, mostly for in-situ nitrogen (N2) generation-a developing technique for enhancing oil recovery and eliminating blockages. Additionally, the kinetics of this reaction, particularly when activated with acids, has been extensively studied. In this work, the effects of five acids-acetic, citric, monochloroacetic, dichloroacetic, and trichloroacetic acids-on thermochemicals were studied, and the impact of several parameters on sodium nitrite (NaNO2) and ammonium chloride (NH4Cl) was examined, such as concentration, temperature, and pH. Experimental results show that acetic acid produced the maximum volume of nitrogen, generating up to 20% more gas than other acids at 82 °C and 3.39 mol/L concentration. Furthermore, the concentration of reactants strongly affected the gas production rate, showing a near-linear relationship. The reaction's efficiency improved at elevated temperatures, with optimal gas generation between 70 and 90 °C. Additionally, pH control within the studied range minimized by-products NO and NO2. Due to its optimal molecular structure and catalytic properties, Acetic acid enhances the efficiency of N2 generation, making it promising for oilfield operations and reservoir enhancement. The study also highlights that the acid's strength and structure play important roles in the reaction, with the structure being a key factor as a catalyst.

The treatment of industrial high-salinity nitrate wastewater remains a considerable challenge, particularly for low-concentration nitrate (<100 ppm), wherein conventional biological methods exhibit limited efficiency. Herein, we report a tandem Co-OV/TiO2@TP photoelectrocatalyst fabricated in situ on a titanium substrate that integrates oxygen vacancies (OVs) and cobalt (Co) sites to drive a sequential reduction-oxidation process for deep nitrate removal. Density functional theory (DFT) calculations and in situ characterization reveal that OVs serve as preferential sites for nitrate adsorption, while adjacent Co sites promote water dissociation to generate active hydrogen species (*H), synergistically enabling the reduction of nitrate (NO3[-]) to ammonium (NH4[+]). Critically, the chloride ions naturally present in the wastewater are oxidized in situ to generate ClO[-], which subsequently converts NH4[+] to N2, achieving complete nitrate removal. This catalyst achieves an impressive NO3[-]-N removal efficiency of 98% and nearly 100% N2 selectivity under neutral conditions with visible light irradiation at -1.5 V (vs. SCE), showing a 67% enhancement over the OV-catalyst. Moreover, this system demonstrates excellent chloride tolerance, wide pH adaptability, and sustained performance over 26 consecutive cycles (104 h), offering an efficient strategy for the self-purifying treatment of industrial high-salinity nitrate wastewater.

Nitrogen addition significantly affects soil aggregate stability by altering the aggregate microenvironment. Although the ecological effects of nitrogen addition on soil aggregates have been extensively investigated, studies specifically focusing on the responses of soil aggregate stability in Larix olgensis forest understories remain scarce. The effects of different forms of nitrogen addition (urea (CO(NH2)2), ammonium chloride (NH4Cl), and sodium nitrate (NaNO3)) were investigated at 20 kg N·ha[-1]·yr[-1] across all treatments, and the physicochemical properties, stability, and microbial community composition of soil aggregates were determined to analyze soil aggregate stability. NaNO3 significantly increased soil nutrient contents, promoted the formation of macroaggregates, and significantly enhanced soil aggregate stability. NH4Cl significantly decreased bacterial diversity in microaggregates, while NaNO3 significantly elevated fungal diversity in macroaggregates. CO(NH2)2 and NH4Cl increased the relative abundances of Ascomycota and Proteobacteria in microaggregates, whereas NaNO3 elevated the relative abundances of Mortierellomycota and Gemmatimonadetes in soil aggregates of all particle sizes. These results indicated that NaNO3 was more effective in improving soil aggregate stability and exerted regulatory effects on microbial community structure compared to the other nitrogen forms. These findings can provide a theoretical basis for an in-depth understanding of the microecological processes of forest soil aggregates under the context of nitrogen deposition.

To address the issues of high wastewater treatment costs and the lack of recycling associated with conventional precipitants such as oxalic acid and ammonium bicarbonate in rare earth precipitation processes, this study proposes a novel gradient alkali conversion-carbonation method based on a green process coupling "rare earth chloride alkali conversion-carbonation with sodium chloride electrolysis." The primary scientific objective is to elucidate the crystallization mechanism and to achieve controlled preparation of high-quality lanthanum carbonate. By gradient-controlling the addition sequence and rate of alkali liquor and CO2, lanthanum carbonate tetrahydrate was successfully synthesized. Characterization by XRD, SEM, ICP, and laser particle size analysis indicates that the product prepared by the gradient alkali conversion-carbonation method exhibits a single phase with high crystallinity, as evidenced by sharp and clear XRD diffraction peaks. Furthermore, the median particle size of the product obtained via this method is relatively large, reaching approximately 10 μm, while the particle size distribution Span value remains around 1.0. Mechanistic studies suggest that this method effectively regulates the crystallization process by precisely controlling the introduction and slow dissolution of the La(OH)3 precursor, thereby reducing the supersaturation of the system during carbonation and facilitating the dissolution-reprecipitation of La[3+]. This work provides a theoretical basis for the preparation of high-quality rare earth carbonates and a process reference for the green recycling route.

The widespread use of antibiotics has led to their persistent accumulation in aquatic environments. Although flocculation is cost-effective, traditional flocculants exhibit limited removal efficiency for antibiotics. To address this problem, a novel cellulose-based flocculant (CE-DMC) was synthesized from paper pulp rejects. The methacryloxyethyltrimethyl ammonium chloride (DMC) monomer was successfully grafted onto the cellulose backbone with a grafting rate of 64 %, endowing CE-DMC with high positive charge density (+71.1 mV at pH 6) and a branched architecture. Flocculation experiments demonstrated the superior performance of CE-DMC in removing four representative antibiotics. Notably distinct removal efficiencies were achieved: ofloxacin exhibited the highest removal (52.6 %), followed by sulfamethoxazole (36.4 %), norfloxacin (30.9 %), and amoxicillin (29.8 %), reflecting differential interaction mechanisms with the adsorbent. The flocculation mechanism of CE-DMC could be concluded as follows: (1) charge neutralization via quaternary ammonium groups of DMC chains, (2) n-π* electron donor-acceptor interactions and π-π* conjugated interactions mediated by benzene rings and furan rings of cellulose skeleton, and (3) hydrogen bonding force provided by the hydroxyl group from the cellulose skeleton and the DMC chains. Notably, coexisting humic acid (HA) and kaolin enhanced antibiotic removal efficiency by forming large composite pollutants via n-π* electron donor-acceptor interactions, hydrogen bonding forces, and π-π* conjugated interactions. CE-DMC synergistically removed antibiotics and co-pollutants, with its flocculation mechanism elucidated through structure-activity relationships and structural determinants. This work advances the rational design of natural polymer-based flocculants for multi-mechanistic contaminant removal.

Rational design of deep eutectic solvents (DESs) for selective biomass fractionation requires molecular-level insights into how composition governs lignin-cellulose disruption. While choline chloride-based DESs dominate research, the choline hydroxyl group strongly sequesters chloride ions, limiting anion-mediated delignification. We present a systematic molecular dynamics investigation of tetraethylammonium chloride (TEACl)-based DESs, where the absence of hydroxyl functionality enhances chloride mobility, paired with urea (URE) or lactic acid (LAC) as hydrogen bond donors in binary systems, and 1,4-butanediol (BDO) in ternary formulations. All-atom simulations over 300 ns reveal distinct solvation mechanisms: urea-based DESs form stable solvation shells that moderately weaken cohesion, whereas lactic acid-based systems exhibit dynamic hydrogen-bond networks with high chloride recruitment, driving delignification through synergistic anion-HBD interactions. Ternary BDO incorporation further enhances chloride mobility and accelerates hydrogen-bond turnover. Critically, the TEACl:LAC:BDO system achieves the most pronounced reduction in lignin-lignin and cellulose-lignin interfacial bonds, significantly outperforming other formulations. Analyses establish that delignification efficiency correlates more strongly with dynamic hydrogen-bond exchange and chloride accessibility than with bulk viscosity or static solvation strength. These findings provide a comprehensive computational framework demonstrating that non-choline quaternary ammonium-based DESs with acidic, polyol-modified formulations enable superior biomass fractionation through enhanced ionic participation. These structure-performance relationships offer rational design principles for optimized green solvents in sustainable biorefinery applications.

Cationic polymers (polycations) represent a promising class of antimicrobial compounds whose physicochemical and biological properties can be tailored through appropriate structural design. The positive charge of these macromolecules indicates possible interactions with biological membranes. In this work, polycations differing in chemical structure (poly(2-(dimethylamino)ethyl methacrylate (PDMAEMA), poly(3-methacrylamido propyl trimethyl ammonium chloride) (PMAPTAC)) and molecular weight were investigated for their antifungal activity. The studies focused on the interactions of the polycations with model Candida albicans membranes that is the monolayers composed of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoethanolamine (POPE), 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC), and ergosterol. Model systems were employed to verify the mechanisms underlying polycation-membrane interactions. The antifungal activity of these compounds against various fungi was also tested. The results showed that the tested compounds exhibit different modes and strengths of interaction with ergosterol-containing membranes. Among the analyzed polymers, PDMAEMA exhibited significant effects on model systems causing changes in lipid packing and an increase in membrane fluidity, whereas PMAPTAC was less effective. Moreover, the polymer with a lower molecular weight modifies membrane properties more strongly compared to its higher-molecular-weight counterpart and additionally exhibits a greater affinity for membranes with a higher ergosterol content. PDMAEMA and PMAPTAC polymers exhibit selective antifungal activity against several opportunistic molds, particularly against Fusarium spp., Trichophyton spp., Candida parapsilosis, and Cryptococcus neoformans. The coexistence of selective antifungal activity and overall comparable antimycotic efficacy among the tested polymers highlights the prominent role of fungal cell properties in determining their susceptibility to polymers tested. Moreover, the selective toxicity of these compounds may be determined by the content of ergosterol in membranes.

Diffusion coefficients and viscosities of tetrabutylammonium dihydrogen phosphate ([NBu4][+][H2PO4][-]), potassium dihydrogen phosphate (K[+][H2PO4][-]), tetrabutylammonium bromide ([NBu4][+][Br][-]), tetrabutylammonium chloride ([NBu4][+][Cl][-]), and biologically relevant phosphate salts adenosine monophosphate (AMP), adenosine diphosphate (ADP), and adenosine triphosphate (ATP) were measured in aqueous solutions as a function of concentration across millimolar concentrations. The [NBu4][+] cation makes the solutions viscous at high millimolar concentrations, and there was no significant evidence of aggregation of the [H2PO4][-] anion. At higher millimolar concentrations, ATP, ADP, and AMP aggregate in aqueous solutions. The increasing concentration of ATP and ADP leads to increased activity of three different enzymes: cytochrome c, laccase, and horseradish peroxidase.