Search Results (411)

The growing demand for high-energy, safe, and sustainable lithium-ion batteries has increased interest in nickel-rich cathode materials and solid-state electrolytes. This study presents a scalable wet-processing method for fabricating composite cathodes for all-solid-state batteries. The cathodes studied herein are high-nickel LiNi_0.90Mn_0.05Co_0.05O₂, NMC955, the sulfide-based electrolyte Li₆PS₅Cl, and alternative binders—polyvinyl alcohol (PVA) and polyisobutylene (PIB)—dispersed in toluene, a non-polar solvent compatible with the electrolyte. After fabrication, the cathodes were characterized using SEM/EDX, sheet resistance, and Hall effect measurements. Electrochemical tests were additionally performed in all-solid-state battery half-cells comprising the synthesized cathodes, lithium metal anodes, and Li₆PS₅Cl as the separator and electrolyte. The results show that both PIB and PVA formulations yielded conductive cathodes with stable microstructures and uniform particle distribution. Electrochemical characterization exposed that the PVA-based cathode outperformed the PIB-based counterpart, achieving the theoretical capacity of 192 mAh·g⁻¹ even at 1C, whereas the PIB cathode reached a maximum capacity of 145 mAh.g⁻¹ at C/40. Post-mortem analysis confirmed the structural integrity of the cathodes. These findings demonstrate the viability of NMC955 as a high-capacity cathode material compatible with solid-state systems. Full article

Peptide-induced disruption of lipid membranes is central to both amyloid diseases and the activity of antimicrobial peptides. Here, we combine all-atom molecular dynamics simulations with biophysical experiments to investigate how four amphipathic peptides interact with lipid bilayers. All peptides adsorb on the membrane surface. Peptide M01 [Ac-(FKFE)₂-NH₂] self-assembles into $\beta$-sheet nanofibrils that span both leaflets of the membrane, creating water-permeable channels. The other three peptides adopt $\alpha$-helical structures at the water–lipid interface. Peptide M02 [Ac-FFKKFFEE-NH₂], a sequence isomer of M01, does not form $\beta$-sheet aggregates and is too short to span the bilayer, resulting in no observable water permeation across the membrane. Peptides M03 and M04 are $\alpha$-helical isomers long enough to span the bilayer, with a polar face that allows the penetration of water deep inside the membrane. For the M03 peptide [Ac-(FFKKFFEE)₂-NH₂], insertion into the bilayer starts with the nonpolar N-terminal amino acids penetrating the hydrophobic core of the bilayer, while electrostatic interactions hold negative residues at the C-terminus on the membrane surface. The M04 peptide, [Ac-FFKKFFEEFKKFFEEF-NH₂], is made by relocating a single nonpolar residue from the central region of M03 to the C-terminus. This nonpolar residue becomes unfavorably exposed to the solvent upon insertion of the N-terminal region of the peptide into the membrane. Consequently, higher concentrations of M04 peptides are required to induce water permeation compared to M03. Overall, our comparative analysis reveals how subtle rearrangements of polar and nonpolar residues modulate peptide-induced water permeation. This provides mechanistic insights relevant to amyloid pathology and antimicrobial peptide design. Full article

Synchronous fluorescence spectra are presented to investigate solute–solvent interactions in liquids. To this end, the spectra of 2-amino-7-nitro-fluorene (ANF) in six different solvents—acetic anhydride, acetone, acetonitrile, benzene, chlorobenzene, and ethyl acetate—are presented. The study also examines ANF’s synchronous fluorescence signals at five temperatures from 25 °C to 5 °C, providing a comprehensive analysis of its fluorescence characteristics in different environments and temperatures. An ANF sample dissolved in benzene at 5 °C produced a synchronous band with the largest intensity and smallest frequency shift. The results show that higher-intensity peaks are obtained at lower temperatures with solvents with a small dipole moment and dielectric constant. This suggest that the best conditions to detect ANF and similar molecules at very low concentrations are with non-polar solvents at low temperatures. Full article

Main-chain conjugated and non-conjugated polyelectrolytes are an important class of materials that have many technological applications ranging from fire-retardant materials to carbon-nanotube composites, nonlinear optical materials, electrochromic materials for smart windows, and optical sensors for biomolecules. Here, we describe a series of poly(pyridinium salt)s-fluorene containing 9,9-bis(4-aminophenyl)fluorene moieties with various organic counterions that were synthesized using ring-transmutation polymerization and metathesis reactions, which are non-conjugated polyelectrolytes. Their chemical structures were characterized by Fourier transform infrared (FTIR), proton (¹H) and fluorine 19 (¹⁹F) nuclear magnetic resonance (NMR) spectrometers, and elemental analysis. They exhibited polyelectrolytic behavior in dimethyl sulfoxide. Their lyotropic liquid-crystalline phases were examined by polarizing optical microscopy (POM) and small angle X-ray scattering (SAXS) studies. Their emission spectra exhibited a positive solvatochromism on changing the polarity of solvents. They emitted greenish-yellow lights in polar organic solvents. They formed aggregates in polar aprotic and protic solvents with the addition of water (v/v, 0–90%), whose λ_em peaks were blue shifted. Full article

Cyanobacterial blooms are becoming increasingly frequent and intense worldwide, often dominated by Microcystis aeruginosa, a species capable of producing a wide array of bioactive metabolites beyond microcystins. This study evaluates the ecotoxicological potential of a non-microcystin-producing strain, M. aeruginosa CCIBt3106, using acute immobilization assays with three microcrustacean species: Daphnia similis, Artemia salina, and Parhyale hawaiensis. Biomass was extracted using solvents of varying polarity, and selected extracts (aqueous and 50% methanol) were further fractionated and analyzed via high-resolution liquid chromatography–tandem mass spectrometry (HR-LC-MS/MS). Significant toxicity was observed in D. similis and P. hawaiensis, with EC₅₀ values ranging from 660 to 940 µg mL⁻¹. Metabolomic profiling revealed the presence of chemically diverse metabolite classes, including peptides, polyketides, and fatty acyls, with putative annotations linked to known bioactivities. These findings demonstrate that cyanobacterial strains lacking microcystins can still produce complex metabolite mixtures capable of inducing species-specific toxic effects under environmentally relevant exposure levels. Overall, the results highlight the need to expand ecotoxicological assessments and monitoring frameworks to include non-microcystin cyanobacterial metabolites and strains in water quality management. Full article

The novel benzanthrone derivative, 2-bromo-3-aminobenzo[de]anthracene-7-one (2-Br-3-NH₂BA), was synthesized and extensively characterized to investigate its photophysical behavior in various solvents. It was prepared through selective bromination of 3-aminobenzanthrone using N-bromosuccinimide in dimethylformamide at −20 °C. Featuring a donor–π–acceptor (D–π–A) structure, 2-Br-3-NH₂BA exhibits pronounced solvatochromism due to the intramolecular charge transfer (ICT) between the amino donor and the carbonyl acceptor groups. Optical measurements conducted in eight solvents of varying polarity revealed a significant bathochromic shift in both absorption and fluorescence emission, with emission maxima red-shifting by over 110 nm from non-polar to polar environments. Corresponding reductions in the optical band gap energies, as calculated from Tauc plots, further support solvent-induced electronic state modulation. Additionally, quantum yield analysis showed higher fluorescence efficiency in non-polar solvents, while polar solvents induced twisted intramolecular charge transfer (TICT), leading to emission quenching. These findings demonstrate the sensitivity of 2-Br-3-NH₂BA to environmental polarity, making it a promising candidate for color-tunable luminescent applications in optoelectronics and sensing. However, further studies in the solid state are required to validate its applicability in device architectures such as OLEDs. Full article

Poly(acrylonitrile-butadiene-styrene) (ABS) is a common polymer used in toys, automobile parts, and membranes. Membranes fabricated with this copolymer commonly employ toxic solvents and have a dense architecture, which may not work in all applications. This work investigates the synthesis of ABS membranes, using green solvents and the influence of additives on the phase inversion process during the non-solvent-induced phase separation. The addition of water-soluble additives, ethanol, and acetone is hypothesized to provide additional control over viscosity and volatility, and, consequently, impact the phase inversion process. Membranes were fabricated with PolarClean and with various additive concentrations and evaporation times. The resulting membranes were characterized using scanning electron microscopy (SEM) and a pycnometer to visualize the pore structure and obtain porosity information. Membrane performance, including water flux and bovine serum albumin rejection, was evaluated using dead-end cell filtration. Membranes fabricated using only PolarClean had fingerlike pore morphology and relatively low protein rejection. The addition of additives resulted in a change in pore architecture and rejection, which is hypothesized to be a result of additives’ volatility, humidity, and destabilization of liquid–liquid separation. This study provides a more detailed understanding of the impact of additives on the resulting ABS membrane structure and performance, with a focus on safer solvents. Full article

Carbon dioxide, the primary greenhouse gas responsible for global warming, represents today a critical environmental challenge for humans. Mitigating CO₂ emissions and other greenhouse gases is a pressing global concern. The primary goal of this study is to investigate the potential of particular ionic liquids (ILs) in capturing CO₂ for the sweetening of natural and other gases. The solubility of CO₂ was measured in three distinct ILs, which shared a common anion (triflate, TfO) but differed in their cations. The selected ionic liquids were {1-butyl-3-methylimidazolium triflate [BMIM][TfO], 1-butyl-1-methylpyrrolidinium triflate [BMP][TfO], and 1-butyl-4-methylpyridium triflate [MBPY][TfO]}. The solvents were screened based on results from a molecular computational study that predicted low CO₂ Henry’s Law constants. Solubility measurements were conducted at 303.15 K, 323.15 K, and 343.15 K and pressures up to 1.5 MPa using a gravimetric microbalance (IGA-003). The CO₂ experimental results were modeled using the Peng–Robinson Equation of state with three mixing rules: van der Waals one (vdWI), van der Waals two (vdWII), and the non-random two-liquid (NRTL) Wong–Sandler (WS) mixing rule. For the three ILs, the NRTL-WS mixing rule regressed the data with the lowest average deviation percentage of 1.24%. The three solvents had similar alkyl chains but slightly different polarities. [MBPY][TfO], with the largest size, exhibited the highest CO₂ solubility at all three temperatures. Calculation of its relative polarity descriptor (N) shows it was the least polar of the three ILs. Conversely, [BMP][TfO] showed the highest Henry’s Law constant (lowest solubility) across the studied temperature range. Comparing the results to published data, the study concludes that triflate-based ionic liquids with three fluorine atoms had lower capacity for CO₂ compared to bis(trifluoromethylsulfonyl) imide (Tf2N)-based ionic liquids with six fluorine atoms. Additionally, the study provided data on the enthalpy and entropy of absorption. A final comparison shows that the ILs had a lower CO₂ capacity than Selexol, a solvent widely used in commercial carbon capture operations. Compared to other ILs, the results confirm that the type of anion had a more significant impact on solubility than the cation. Full article

It has been demonstrated that the traditional hydrometallurgical method is still economically viable in several industrial applications such as Bayer, Boix, Platsol, Sherrit-Gordon, and so on. The conventional extraction technique of valuable metals from their ores using an aqua medium has several challenges. The following can be listed for the illustration of this: (1) Inorganic acids used during the leaching process have been proven to be non-environmentally friendly and ready to lead to non-selective processes in general, except in rare cases used in alkaline environments. (2) Special linings are required in the reactors used due to the corrosive impact of acids such as HCl and H₂SO_4, especially when leaching at high temperatures, rendering all processes costly. (3) Practically, using inorganic acids while leaching samples containing amorphous silicate phases leads to gel formation. Solvometallurgy overcomes these challenges by substituting the aqueous phase for other polar solvents, such as polar molecular organic or ionic solvents. The advantage of this substitution lies in the ability to manipulate metal ion distribution using solvents with varying solvation properties. This review examines the potential of solvometallurgical processes (solvoleaching) over conventional hydrometallurgy as viable alternatives for metal extraction from sulfide ores. It highlights the key distinctions between hydrometallurgy and solvometallurgy while emphasizing the potential economic and environmental advantages solvometallurgy offers. Full article

Background/Objectives: Haloxylon griffithii is a medicinal plant possessing therapeutic effects in disorders associated with the gastrointestinal (GIT) system. This research aims to study the pharmacological activity of Haloxylon griffithii in a multidimensional manner, involving phytochemistry screening and in vitro and in vivo experiments. Methods: The whole dried plant was extracted with 80% methanol and further fractionation using solvents of increasing polarity. GC-MS analysis was performed on the crude extract to discover volatile compounds. The spasmolytic/spasmogenic effect was assessed in isolated rabbit jejunum using spontaneous and K⁺-induced contractions, as well as contractions induced by increasing concentrations of calcium ions in depolarized tissue. Antidiarrheal activity was evaluated in Swiss albino rats/mice (n = 6/group) using castor oil-induced diarrhea and peristaltic index models. In silico ADMET screening was conducted via SwissADME and pkCSM. Results: The GC-MS profiling of H. griffithii revealed the presence of 59 phytochemicals and a rare azulene derivative and constituents, including α-santonin and hexadecanoic acid esters, with favorable pharmacokinetic profiles, as predicted using SwissADME and pkCSM computational tools. The in vitro and in vivo experiments revealed the significant calcium channel blocking activity in non-polar fractions (n-hexane and ethyl acetate), while the polar extracts (ethanolic, aqueous) exhibited cholinergic effects, indicating a dual mode of action. Conclusions: This was a first-time demonstration of both antidiarrheal and smooth muscle-relaxant activity in H. griffithii, supported by GC-MS profiling and pharmacological assay. The findings lend scientific credibility to the traditional use of the plant in community healthcare, while also reinforcing the need for further pharmacological and clinical studies to explore its potential in drug development. Full article

Sample preparation is the most time-consuming part of phytochemical, agricultural chemical, and food science studies and is constantly being improved. This includes the development of modern extraction methods, such as high-pressure extraction and automatic steam distillation. These methods feature high reproducibility, low time consumption, and the ability to run several parallel samples. However, the ideal parameters for processing plant materials using these methods have not been fully explored. These parameters include those that produce the highest yield and those that produce yields comparable to less modern extraction techniques, which would allow for a comparison of data to a wide range of preexisting data obtained from plant materials in different growing locations and climates. As such, this study examined extracts produced by reflux extraction, high-pressure extraction, and traditional and automatic steam distillation for three plants: aronia, holy basil, and juvenile ginger. High-pressure extraction methods were developed to produce extracts similar to those produced by reflux extraction, while automatic distillation methods were developed to produce high essential oil yields. The automatic steam distillation yields were 55.81 ± 1.97 mg/g of holy basil, 61.52 ± 0.61 mg/g of ginger, and 45.79 ± 1.38 mg/g of aronia. The high-pressure extraction yields were 11.09 ± 1.46 mg GAE/g of holy basil, 154.50 ± 17.10 mg of anthocyanins/mL of aronia, 6.60 ± 0.55 mg GAE/g of ginger, and 3.27 ± 0.25 mg GAE/g of ginger. These were compared to reflux yields of 32.71 ± 5.22 mg GAE/g of holy basil, 253.00 ± 39.56 mg of anthocyanin/mL of aronia, and 3.34 ± 2.07 mg GAE/g of ginger. Full article

Conventional mild hydrotreatment processes of bio-oil present significant challenges of a high degree of polymerization, a low oil yield, high coke formation, and poor catalyst recovery. To address these challenges, the current study looked into investigating and enhancing the properties of raw bio-oil organic phase samples via a solvent-assisted stabilization approach using methanol (METH), ethanol (ETH), isopropyl alcohol (IPA), and ethyl ether (DME). Solvents like methanol (METH) and ethanol (ETH), which are highly polar, yielded higher oil fractions (64% and 62%, respectively) compared to less polar solvents like ethyl ether (DME) at 59%. Isopropyl alcohol (IPA), with intermediate polarity, achieved a balanced oil yield of 63%, indicating its ability to dissolve both polar and non-polar components. Moisture reduction in stabilized bio-oils followed the order IPA > ETH > METH > DME, with IPA showing the highest reduction due to its structural characteristics facilitating dehydration. Viscosity reduction varied, with IPA > ETH > DME > METH. Carbon recovery in stabilized bio-oils ranged from 65% to 75% for DME, ETH, and METH and was 71% for IPA. The heating values of stabilized bio-oils ranged from 28 to 29 MJ/kg, with IPA-stabilized bio-oil showing the highest value (29.05 ± 0.06 MJ/kg). METH demonstrated high efficiency (74.8%) in stabilizing bio-oil, attributed to its strong hydrogen-donating capability. ETH followed closely at 69.5%, indicating its comparable performance in bio-oil stabilization. With moderate efficiency (69.3%), IPA presents a balanced alternative considering its molecular structure and hydrogen solubility. In contrast, DME exhibited lower efficiency (63.6%) due to its weaker hydrogenation capability and propensity for undesired side reactions. The current study suggests that subcritical conditions up to 200 °C are adequate for METH, ETH, and IPA in bio-oil stabilization, comparable to results obtained under supercritical conditions. Full article

Four silane-containing Schiff base oligomers (o-SBNs and o-SBBs) were synthesized by high-temperature polycondensation reactions using silicon-based dialdehydes with naphthalene and 1,1’-binaphthalene diamine derivates. The samples showed a moderate solubility in common organic solvents, where the incorporation of TPS cores into o-SBN2 allows the formation of highly soluble material in non-polar solvents with higher molecular weights (11.58 kDa) and polydispersity. All oligo-SBs displayed high thermal resistance (above 450 °C), showing enhanced thermal stability for TPS-containing oligomers, with the degradation temperature exceeding 530 °C (o-SBB2) and high T_g values due to the higher aromatic content granted by TPS and 1,1’-binaphthalene moieties. Optical results of the oligo-SBs showed broad absorption and emission behavior in the visible spectrum, ranging from deep blue (o-SBN1 and o-SBB1) to blue (o-SBN2 and o-SBB2). The structure promotes a clear bathochromic shift for TPS-based oligomers, attributed to an extended π-conjugation across the backbone. In addition, the π-π overlap effect highlights larger Stokes shifts for the DMS core oligomers o-SN2 (133 nm) and o-SBB1 (195 nm). The oligo-SBs were found to be wide-bandgap materials, with E_g^opt values in the range of 2.60 eV to 3.67 eV. The higher molecular weight of o-SBN2, which provided an extended π-conjugation, allows the lowest value of E_g^opt (2.60 eV) to be achieved. In addition, DFT, TDDFT and EDDM calculations were performed on trimeric oligo-SBs, revealing that HOMOs are localized in the amine-terminal fraction, while LUMOs are localized over the terminal aldehyde groups. These findings highlight the used DMS and TPS cores in Schiff base materials, providing valuable insights into fine-tuning physicochemical properties through the use of suitable building blocks and their potential as optoelectronic materials. Full article

The London dispersive and polar surface properties of solid materials are very important in many chemical processes, such as adsorption, coatings, catalysis, colloids, and mechanical engineering. One of the materials, a styrene–divinylbenzene copolymer modified with 5-hydroxy-6-methyluracil at different percentages, has not been deeply characterized in the literature, and it isparticularly crucial to determine its London dispersive and polar properties. Recent research in the inverse gas chromatography (IGC) technique allowed a full determination of the surface properties of a styrene–divinylbenzene copolymer modified with 5-hydroxy-6-methyluracil by using well-known polar and non-polar organic solvents and varying the temperature. Applying the IGC technique at infinite dilution resulted in the retention volume of adsorbed molecules on styrene–divinylbenzene copolymer modified with 5-hydroxy-6-methyluracil at different percentages, using the Hamieh thermal model and our recent results on the separation of the two polar and dispersive contributions to the free energy of interaction. The surface properties of these materials, such as the surface free energy of adsorption, the polar acid and base surface energy, and the Lewis acid–base parameters, were obtained as a function of temperature and for different percentages of 5-hydroxy-6-methyluracil. The obtained results proved that the polar free energy of adsorption on styrene–divinylbenzene copolymer increased when the percentage of 5-hydroxy-6-methyluracil (HMU) increased. However, a decrease in the London dispersive surface energy of the copolymer was observed for higher percentages of 5-hydroxy-6-methyluracil. A Lewis amphoteric character was shown for the copolymer with the highest acidity, while the basicity linearly increased when the percentage of HMU increased. Full article

Proteins and their surrounding hydration water engage in a dynamic interplay that is critical for maintaining structural stability and functional integrity. However, the intricate coupling between protein dynamics and the structural order of hydration water remains poorly understood. Here, we employ all-atom molecular dynamics simulations to investigate this relationship across four representative proteins. Our results reveal that protein residues with greater flexibility or solvent exposure are surrounded by more disordered hydration water, akin to bulk water, whereas rigid and buried non-polar residues are associated with structurally ordered hydration shells. Due to their strong hydrogen bonding and electrostatic interactions, charged residues exhibit the most disordered hydration water, while non-polar residues are associated with the structurally most ordered hydration water. We further uncovered a positive correlation between the relaxation dynamics of protein residues and their hydration water: slower (faster) protein relaxation is coupled with slower (faster) relaxation of the structural order of hydration water. Notably, this coupling weakens with increasing residue flexibility or solvent exposure, with non-polar residues displaying the strongest coupling, and charged residues the weakest. To further uncover their coupling mechanism, we elucidate residue-specific coupled fluctuations between protein residues and hydration water by generating scatter plots. These findings provide a comprehensive understanding of the mechanisms underlying protein–water interactions, offering valuable insights into the role of hydration water in protein stability, dynamics, and function. Full article