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In this work, we determine the dissociation line of the nitrogen (N2) hydrate by computer simulation using the TIP4P/Ice model for water and the TraPPE force field for N2. This work is the natural extension of Paper I, in which the dissociation temperature of the N2 hydrate has been obtained at 500, 1000, and 1500 bar [Algaba et al., J. Chem. Phys. 159, 224707 (2023)] using the solubility method and assuming single occupancy. We extend our previous study and determine the dissociation temperature of the N2 hydrate at different pressures, from 500 to 4500 bar, taking into account the single and double occupancy of the N2 molecules in the hydrate structure. We calculate the solubility of N2 in the aqueous solution as a function of temperature when it is in contact with a N2-rich liquid phase and when in contact with the hydrate phase with single and double occupancy via planar interfaces. Both curves intersect at a certain temperature that determines the dissociation temperature at a given pressure. We observe a negligible effect of occupancy on the dissociation temperature. Our findings are in very good agreement with the experimental data taken from the literature. We have also obtained the driving force for the nucleation of the hydrate as a function of temperature and occupancy at several pressures. As in the case of the dissociation line, the effect of occupancy on the driving force for nucleation is negligible. To the best of our knowledge, this is the first time that the effect of the occupancy on the driving force for nucleation of a hydrate that exhibits sII crystallographic structure is studied from computer simulation. [ABSTRACT FROM AUTHOR]

8-oxo-7,8-dihydro-2′-dexyoguanine (8-oxo-dG) can be tautomerized to a 6-enolate,8-keto tautomer through nearby-NH deprotonation at elevated pH. In this work, the N3-protonated 8-oxo-dG tautomers in deuterated pH-buffer solutions were studied using steady-state UV/Vis, FTIR, and ultrafast two-dimensional IR spectroscopies. The presence of 6,8-diketo and C6-anionic tautomers at neutral to basic conditions (pD = 7.4–12.0) was revealed by UV/Vis and FTIR results and was further confirmed by 2D IR signals in both diagonal and off-diagonal regions. However, the C6-enol tautomer, which may be an intermediate during the transition from 6,8-diketo to C6-enolate,C8-keto, was not observed appreciably due to its extreme low population. Furthermore, the neutral-to-anionic tautomeric transition of N3H-8-oxo-dG studied in this work occurs under more basic conditions than the N1H-8-oxo-dG reported previously, showing a higher pKa value for N3H than N1H. Finally, vibrational relaxation of the carbonyl stretching mode was found to be both molecular site dependent and pD dependent for 8oxo-dG. Taken together, this work shows that the ultrafast infrared spectroscopic method is effective for examining tautomers and their dynamics in nucleic acids. [ABSTRACT FROM AUTHOR]

This paper presents the first implementation of a coupling between advanced wavefunction theories and molecular density functional theory (MDFT). This method enables the modeling of solvent effect into quantum mechanical (QM) calculations by incorporating an electrostatic potential generated by solvent charges into the electronic Hamiltonian. Solvent charges are deduced from the spatially and angularly dependent solvent particle density. Such a density is obtained through the minimization of the functional associated with the molecular mechanics (MM) Hamiltonian describing the interaction between the fluid particles. The introduced QM/MDFT framework belongs to QM/MM family of methods, but its originality lies in the use of MDFT as the MM solver, offering two main advantages. First, its functional formulation makes it competitive with respect to sampling-based molecular mechanics. Second, it preserves a molecular-level description lost in macroscopic continuum approaches. The excited state properties of water and formaldehyde molecules solvated into water have been computed at the selected configuration interaction (SCI) level. The excitation energies and dipole moments have been compared with experimental data and previous theoretical work. A key finding is that using the Hartree–Fock method to describe the solute allows for predicting the solvent charge around the ground state with sufficient precision for the subsequent SCI calculations of excited states. This significantly reduces the computational cost of the described procedure, paving the way for the study of more complex molecules. [ABSTRACT FROM AUTHOR]

Here, we report the frequency-dependent spectrum of ice Ih in the range of 0.2–2 THz. We confirm the presence of a feature that blue-shifts from around 1.55–1.65 THz with a decreasing temperature from 260 to 160 K. There is also a change in the trend of the refractive index of ice corresponding to a dispersion, which is also around 1.6 THz. The features are reproduced in data acquired with three commercial terahertz time-domain spectrometers. Computer-simulated spectra assign the feature to lattice translations perpendicular to the 110 and 1 ̄ 10 planes of the ice Ih crystal. The feature's existence should be recognized in the terahertz measurements of frozen aqueous solution samples to avoid false interpretations. [ABSTRACT FROM AUTHOR]

In this work, the effects of finite size on the determination of the three-phase coexistence temperature (T3) of the carbon dioxide (CO2) hydrate have been studied by molecular dynamic simulations and using the direct coexistence technique. According to this technique, the three phases involved (hydrate–aqueous solution–liquid CO2) are placed together in the same simulation box. By varying the number of molecules of each phase, it is possible to analyze the effect of simulation size and stoichiometry on the T3 determination. In this work, we have determined the T3 value at 8 different pressures (from 100 to 6000 bar) and using 6 different simulation boxes with different numbers of molecules and sizes. In two of these configurations, the ratio of the number of water and CO2 molecules in the aqueous solution and the liquid CO2 phase is the same as in the hydrate (stoichiometric configuration). In both stoichiometric configurations, the formation of a liquid drop of CO2 in the aqueous phase is observed. This drop, which has a cylindrical geometry, increases the amount of CO2 available in the aqueous solution and can in some cases lead to the crystallization of the hydrate at temperatures above T3, overestimating the T3 value obtained from direct coexistence simulations. The simulation results obtained for the CO2 hydrate confirm the sensitivity of T3 depending on the size and composition of the system, explaining the discrepancies observed in the original work by Míguez et al. [J. Chem Phys. 142, 124505 (2015)]. Non-stoichiometric configurations with larger unit cells show a convergence of T3 values, suggesting that finite-size effects for these system sizes, regardless of drop formation, can be safely neglected. The results obtained in this work highlight that the choice of a correct initial configuration is essential to accurately estimate the three-phase coexistence temperature of hydrates by direct coexistence simulations. [ABSTRACT FROM AUTHOR]

We determine the surface tension of aqueous electrolyte solutions in contact with non-polar dielectric media using a thermomechanical approach, which involves deriving the stress tensor from the thermodynamic potential of an inhomogeneous fluid. To obtain the surface tension, we calculate both the normal and tangential pressures using the components of the stress tensor, recently derived by us [Y. A. Budkov and P. E. Brandyshev, J. Chem. Phys. 159, 174103 (2023)] within the framework of Wang's variational field theory. Using this approach, we derive an analytical expression for the surface tension in the linear approximation. At low ionic concentrations, this expression represents the classical Onsager–Samaras limiting law. By utilizing only one fitting parameter, which is related to the affinity of anions to the dielectric boundary, we successfully approximated experimental data on the surface tension of several aqueous electrolyte solutions. This approximation applies to both the solution–air and solution–dodecane interfaces, covering a wide range of electrolyte concentrations. [ABSTRACT FROM AUTHOR]

Developing highly efficient methane (CH4) hydrate storage methods and understanding the hydrate dissociation kinetics can contribute to advancing CH4 gas storage and transport. The effects of tetrabutylammonium bromide (TBAB) (a thermodynamic promoter) addition on the kinetics of CH4 hydrate were evaluated on the microscopic scale using synchrotron x-ray computed tomography (CT) and powder x-ray diffraction. Microscopic observations showed that a 5 wt. % TBAB solution facilitated the nucleation of CH4 hydrate owing to the initial growth of TBAB semi-clathrate hydrate particles. The CH4 hydrate crystals in the CH4 + TBAB hydrate sample were sponge-like with many internal pores and exhibited slightly enhanced self-preservation compared to the pure CH4 hydrate, both in the bulk and after pulverization to a fine powder. This study demonstrates the feasibility of controlling the rate of CH4 hydrate formation and preservation by using aqueous TBAB solutions in CH4 hydrate formation. [ABSTRACT FROM AUTHOR]

Semiconductor nanocrystals (NCs) can function as efficient gain materials with chemical versatility because of their surface ligands. Because the properties of NCs in solution are sensitive to ligand–environment interactions, local chemical changes can result in changes in the optical response. However, amplification of the optical response is technically challenging because of colloidal instability at NC concentrations needed for sufficient gain to overcome losses. This paper demonstrates liquid lasing from plasmonic lattice cavities integrated with ligand-engineered CdZnS/ZnS NCs dispersed in toluene and water. By taking advantage of calcium ion-induced aggregation of NCs in aqueous solutions, we show how lasing threshold can be used as a transduction signal for ion detection. Our work highlights how NC solutions and plasmonic lattices with open cavity architectures can serve as a biosensing platform for lab-on-chip devices. [ABSTRACT FROM AUTHOR]

The nucleation of ice from aqueous solutions is a process essential to myriad environmental and industrial processes, but the physical factors affecting the capacity of different solutes to depress the homogeneous nucleation temperature of ice are yet poorly understood. In this work, we demonstrate that for many binary aqueous solutions of non-ionic solutes, this depression is dominated by the entropy of the liquid phase. Employing the classic Turnbull interpretation of the interfacial free energy γ ∼ T S l i q u i d − S s o l i d and estimating solution entropies with a Flory-style modification of the ideal entropy of mixing that accounts for solute size effects, we demonstrate that mixing entropy alone predicts experimental homogeneous nucleation temperatures across a wide variety of non-ionic solutions. We anticipate that this physical insight will not only enhance a fundamental understanding of homogeneous nucleation processes across fields but also open new avenues to the rational design of aqueous solutions for desired nucleation behaviors. [ABSTRACT FROM AUTHOR]

Experimental and theoretical advances for understanding the temperature of maximum density (TMD) of aqueous solutions are outlined. The main equations that relate the TMD behavior to key thermodynamic properties are stated. The experimental TMD data are classified as a function of the nature of the solute (inorganic electrolytes, non-electrolytes, organic salts and ionic liquids, and amino acids and proteins). In addition, the experimental results that explore the effect of pressure are detailed. These experimental data are rationalized by making use of qualitative and semi-quantitative arguments based on the thermodynamics of aqueous systems. The main theoretical and simulation advances in TMD for aqueous solutions are also shown—including new calculations in the context of the scaled particle theory—and their ability to reproduce the experimental data is evaluated. Finally, new experiments and theoretical and simulation developments, which could give important insights into the problem of TMD for aqueous solutions, are proposed. [ABSTRACT FROM AUTHOR]

In this work, we determine the dissociation line of the nitrogen (N2) hydrate by computer simulation using the TIP4P/Ice model for water and the TraPPE force field for N2. We use the solubility method proposed recently by some of us to evaluate the dissociation temperature of the hydrate at different pressures, from 500 to 1500 bar. Particularly, we calculate the solubility of N2 in the aqueous solution when it is in contact with a N2-rich liquid phase and when in contact with the hydrate phase via planar interfaces as functions of temperature. Since the solubility of N2 decreases with temperature in the first case and increases with temperature in the second case, both curves intersect at a certain temperature that determines the dissociation temperature at a given pressure. We find a good agreement between the predictions obtained in this work and the experimental data taken from the literature in the range of pressures considered in this work. From our knowledge of the solubility curves of N2 in the aqueous solution, we also determine the driving force for nucleation of the hydrate, as a function of temperature, at different pressures. In particular, we use two different thermodynamic routes to evaluate the change in chemical potential for hydrate formation. Although the driving force for nucleation slightly decreases (in absolute value) when the pressure is increased, our results indicate that the effect of pressure can be considered negligible in the range of pressures studied in this work. To the best of our knowledge, this is the first time the driving force for nucleation of a hydrate that exhibits crystallographic structure sII, along its dissociation line, is studied from computer simulation. [ABSTRACT FROM AUTHOR]

Concentrated ionic aqueous electrolytes possess a diverse array of applications across various fields, particularly in the field of energy storage. Despite extensive examination, the intricate relationships and numerous physical mechanisms underpinning diverse phenomena remain incompletely understood. Molecular dynamics simulations are employed to probe the attributes of aqueous solutions containing LiCl, NaCl, KCl, MgCl2, and CaCl2, spanning various solute fractions. The primary emphasis of the simulations is on unraveling the intricate interplay between these attributes and the underlying physical mechanisms. The configurations of cation-Cl− and Cl−–Cl− pairs within these solutions are disclosed. As the solute fraction increases, consistent trends manifest regardless of solute type: (i) the number of hydrogen bonds formed by the hydration water surrounding ions decreases, primarily attributed to the growing presence of counter ions in proximity to the hydration water; (ii) the hydration number of ions exhibits varying trends influenced by multiple factor; and (iii) the diffusion of ions slows down, attributed to the enhanced confinement and rebound of cations and Cl− ions from the surrounding atoms, concurrently coupled with the changes in ion vibration modes. In our analysis, we have, for the first time, clarified the reasons behind the slowing down of the diffusion of the ions with increasing solute fraction. Our research contributes to a better understanding and manipulation of the attributes of ionic aqueous solutions and may help designing high-performance electrolytes. [ABSTRACT FROM AUTHOR]

We perform molecular dynamics simulations of TIP4P/Ice water in solution with trehalose for 3.65 and 18.57 wt. % concentrations and of bulk TIP4P/Ice water at ambient pressure, to characterize the structure and dynamics of water in a sugar aqueous solution in the supercooled region. We find here that TIP4P/Ice water in solution with trehalose molecules follows the Mode Coupling Theory and undergoes a fragile to strong transition up to the highest concentration investigated, similar to the bulk. Moreover, we perform a Mode Coupling Theory test, showing that the Time Temperature Superposition principle holds for both bulk TIP4P/Ice water and for TIP4P/Ice water in the solutions and we calculate the exponents of the theory. The direct comparison of the dynamical results for bulk water and water in the solutions shows upon cooling along the isobar a fastening of water dynamics for lower temperatures, T < 240 K. We found that the counter-intuitive behavior for the low temperature solutions can be explained with the diffusion anomaly of water leading us to the conclusion that the fastening observed below T = 240 K in water dynamics is only fictitious, due to the fact that the density of water molecules in the solutions is higher than the density of the bulk at the same temperature and pressure. This result should be taken into account in experimental investigations which are often carried out at constant pressure. [ABSTRACT FROM AUTHOR]

CO2 and CH4 hydrates are of great importance both from an energetic and from an environmental point of view. It is therefore highly relevant to quantify and understand the rate with which they grow. We use molecular dynamics simulations to shed light on the growth rate of these hydrates. We put the solid hydrate phase in contact with a guest aqueous solution in equilibrium with the pure guest phase and study the growth of both hydrates at 400 bars with temperature. We compare our results with previous calculations of the ice growth rate. We find a growth rate maximum as a function of the supercooling in all cases. The incorporation of guest molecules into the solid structure strongly decelerates hydrate growth. Consistently, ice grows faster than either hydrate and the CO2 hydrate grows faster than the CH4 one because of the higher solubility of CO2. We also quantify the molecular motion required to build the solids under study and find that the distance traveled by liquid molecules exceeds by orders of magnitude that advanced by any solid. Less molecular motion is needed in order for ice to grow as compared to the hydrates. Moreover, when temperature increases, more motion is needed for solid growth. Finally, we find a good agreement between our growth rate calculations and experiments of hydrate growth along the guest–solution interface. However, more work is needed to reconcile experiments of hydrate growth toward the solution among each other and with simulations. [ABSTRACT FROM AUTHOR]

Nucleotides are organic compounds consisting of a phosphate group, a nitrogenous base, namely adenine (A), thymine (T), cytosine (C), or guanine (G), and a sugar, here deoxyribose. The magnitude of the first hyperpolarizability β of these four DNA nucleotides was determined in aqueous solution with the nonlinear optical technique of hyper rayleigh scattering under non resonant conditions at a fundamental wavelength of 800 nm. The smallest value is found to be 1.67 ± 0.15 × 10−30 esu for thymidine-5′-monophosphate and the highest is 1.76 ± 0.16 × 10−30 esu for 2′-guanosine-5′-monophosphate. Polarization resolved studies were also performed to question the symmetry of the first hyperpolarizability tensor and access the ratio of some elements of the first hyperpolarizability tensor. These experimental results were then compared to the theoretical values of these first hyperpolarizabilities obtained with the density functional theory at the level of the PCM-B3LYP/6-31G+(d) basis and taking into account the solvent. [ABSTRACT FROM AUTHOR]

Medium- and low-permeability reservoirs are important in oilfield development. However, due to their characteristics of poor pore permeability and high heterogeneity, the development of suitable technologies has been very difficult. In this study, an in situ emulsifying/ultra-low-interfacial-tension cyclic flooding system has been developed for low- and medium-permeability reservoirs. Based on the hydrophilic-lipophilic balance (HLB) value method, an emulsifying surfactant ASD with Span 80 (sorbitan monooleate) as the main component has been identified as highly promising through screening. At mass fractions of surfactant ASD between 0.2% and 0.6%, the extent of water separation from the emulsion is greatly reduced, and the W/O emulsion can effectively improve the mobility ratio and increase the sweep volume. The surfactant SA synthesized in our laboratory reduces the interfacial tension of crude oil to 10−4 mN m−1. Laboratory core flooding experiments have shown that multiple rounds of alternating injection with aqueous solutions of surfactants ASD and SA can improve oil recovery by 22.25%. Upon injecting a low-viscosity aqueous solution of surfactant ASD, it emulsifies crude oil in situ under reservoir conditions, solving the problems of difficult polymer injection and insufficient spread. Our work provides useful insights for the development of low- and medium-permeability reservoirs. [ABSTRACT FROM AUTHOR]

The global demand for green energy stimulates the need for rechargeable batteries and their components, containing lithium, cobalt, manganese, copper, and nickel. Consequently, the quantitative determination of the battery metals has crucial importance in optimizing associated processes and waste management. The fundamental properties of an analyzer for continuous process and field measurements are sensitivity, selectivity, stability, mobility, and robustness. Unfortunately, these characteristics are lacking in numerous existing methods for metals monitoring. Hence, this gap led us to demonstrate the performance of micro-discharge optical emission spectroscopy (µDOES), a novel online trace metal analyzer. This study shows that the new online analyzer with its simple and compact design can match requirements for real-time determination of metals in aqueous solutions in the field. The performance of the system is defined with copper, nickel, and lithium dissolved in deionized water. The limit of detection (LOD) along with long-term repeatability for Cu, Ni, and Li in continuous analysis reached 0.9, 4.1, and 0.1 µg/L, and 2, 2, and 4.2%, respectively. The applicability of the technique to a real-world application is demonstrated by analyzing a hydrometallurgical black mass sample received from the recycling process of lithium-ion batteries. [ABSTRACT FROM AUTHOR]

The AlCl 3 /ZnCl 2 aqueous solution acts as a benign cellulose solvent, polymerization catalyst for acrylamide monomer, effective ion source for electron transport networks, and dynamic riveting point for hydrogel networks. [Display omitted] The green synthesis strategy for cellulose-containing hydrogel electrolytes is significant for effectively managing resources, energy, and environmental concerns in the contemporary world. Herein, we propose an all-green strategy using AlCl 3 /ZnCl 2 /H 2 O solvent to create cellulose/polyacrylamide-based hydrogel (AZ-Cel/PAM) with expanded hierarchical topologies. The aqueous AlCl 3 /ZnCl 2 facilitates the efficient dissolution of cellulose at room temperature, and the dispersed Al3+-Zn2+ ions autocatalytic system catalyzes in-situ polymerization of acrylamide (AM) monomer. This expands the AM network within the cellulose framework, forming multiple bonding interactions and stable ion channels. The resulting hybrid hydrogel exhibits improved mechanical properties (tensile strength of 56.54 kPa and compressive strength of 359.43 kPa) and enhanced ionic conductivity (1.99 S/m). Furthermore, it also demonstrates excellent adhesion, freeze resistance (−45 °C), and water retention capabilities. Quantum simulations further clarify the mechanical composition and ion transport mechanism of AZ-Cel/PAM hydrogels. The assembled supercapacitor with the hydrogel electrolyte, demonstrates an ideal area-specific capacitance of 203.80 mF/cm2. This all-green strategy presents a novel approach to developing sustainable energy storage devices. [ABSTRACT FROM AUTHOR]

Antibiotics have several negative effects on aquatic ecosystems and are difficult to degrade using traditional water/wastewater treatment methods. As a result, new treatment techniques must be employed to eliminate these contaminants from aquatic environments. Research on the relationship between the decomposing process of antibiotics and different factors by new technologies is scarce. This research focuses on the capability of ozone micro-nano bubbles (OzMNBs) to eliminate the antibiotics ciprofloxacin (CIPR) and levofloxacin (LEVO) in aqueous solutions. We studied the CIPR and LEVO decomposition to different variables through the central composite design method. The main variables included pH, ozonation time, and initial antibiotic concentration. The correlation coefficients of the quadratic model obtained by using the software, Design Expert version 13.0.1. Analysis of variances proved the significance of models and main factors. Verification tests also confirmed that the final optimum conditions of the antibiotics decomposition were: pH 9, ozonation for 40 min and, initial antibiotic concentration of 5 mg/L. In optimum conditions, removal rate of about 97% and 100% was obtained for CIPR and LEVO, respectively. The order of influence of various factors on CIPR and LEVO decomposition were obtained and the interactions between the main factors were also investigated. At the last stage of the research, the efficiency of OzMNBs in the removal of total organic carbon and mineralization of the solutions containing CIPR and LEVO under optimum conditions was examined. [ABSTRACT FROM AUTHOR]

In this study, cost-effective alkali-activated materials made from industrial side streams (blast furnace slag and Na-jarosite) were developed for catalytic applications. The catalytic activity of the prepared materials was examined in catalytic wet peroxide oxidation reactions of a bisphenol A in an aqueous solution. All materials prepared revealed porous structure and characterisation expressed the incorporation of iron to the material via ion exchange in the preparation step. Furthermore, the materials prepared exhibited high specific surface areas (over 200 m2/g) and were mainly mesoporous. Moderate bisphenol A removal percentages (35%–37%) were achieved with the prepared materials during 3 h of oxidation at pH 7–8 and 50°C. Moreover, the activity of catalysts remained after four consecutive cycles (between the cycles the catalysts were regenerated) and the specific surface areas decreased only slightly and no changes in the phase structures were observed. Thus, the prepared blast furnace slag and Na-jarosite-based catalysts exhibited high mechanical stability and showed good potential in the removal of bisphenol A from wastewater through catalytic wet peroxide oxidation. [ABSTRACT FROM AUTHOR]

A new palladium(II) complex containing the previously synthesized 4,10-bis[(3-hydroxy-4-pyron-2-yl)methyl]-1,7-dimethyl-1,4,7,10-tetraazacyclododecane ligand maltonis was prepared and characterized both in solution and in the solid state. Hirshfeld surface and energy framework analyses were also performed. Because maltonis already showed antineoplastic activity, the complexation of Pd(II), chosen as an alternative to Pt(II), was investigated to study its possible biological activity. UV-vis and NMR studies confirmed the formation and stability of the complex in aqueous solution at physiological pH. X-ray diffraction data revealed a structure where the Pd(II) ion is lodged in the dimethyl-cyclen cavity, with maltol rings facing each other (closed shape) even if they are not involved in the coordination. DFT analysis was performed in order to understand the most stable shape of the complex. In view of evaluating its possible bioactive conformation, the DFT study suggested a slight energetic preference for the closed one. The resulting closed complex was stabilized in the X-ray structure by intermolecular interactions that replace the intramolecular interactions present in the optimized complex. According to the DFT calculated formation energies, notwithstanding its rarity, the Pd(II) complex of maltonis is the thermodynamically preferred one among analogous complexes containing different metal ions (Pt(II), Co(II), and Cu(II)). Finally, to study its possible biological activity, the interaction between the Pd(II) complex of maltonis and nucleosides was evaluated through NMR and DFT calculations, revealing a possible interaction with purines via the maltol moieties. [ABSTRACT FROM AUTHOR]

The rising awareness of fire safety among consumers has driven the demand for fire retardants (FRs) that are both cost‐effective and efficient across various industries, particularly in textiles. Traditional FRs often compromise fabric softness, resulting in undesirable tactile texture and stiffness changes. While the external addition of softeners can mitigate the stiffness, it may introduce issues such as a greasy texture and increased flammability. This study introduces ethanolamine polyphosphate (EAPP), an innovative organic polyphosphate, as an effective fire retardant that preserves the softness of textiles. Comprehensive evaluations are conducted on EAPP‐treated textiles, revealing significant improvements in fire retardancy without compromising fabric quality. EAPP treatment (15 wt.% aqueous solutions) increases the limiting oxygen index (LOI) of pure cotton textiles from 17% to 36% and significantly reduces the peak heat release rate (pHRR) and total smoke rate (TSR) as measured by cone calorimetry. Unlike conventional FR products that form FR‐salt crystal particles on the fabric surface after drying, EAPP forms a smooth FR protective layer on the fabric, enhancing mechanical fastness and maintaining tactile qualities. These findings highlight EAPP's potential as a non‐washing durable, spray‐on fire retardant solution for textiles, combining safety with user comfort. [ABSTRACT FROM AUTHOR]

Ammonia borane (AB), with high hydrogen density and stability under ambient conditions, readily releases hydrogen via catalyzed hydrolysis. However, ammonia, a byproduct of hydrogen release, limits its utilization. Citric acid, a safe and cost-effective acid catalyst, for the acid catalyst of AB hydrolysis was investigated in this study to mitigate ammonia emissions while enhancing hydrogen release. Maximal hydrogen release (3 eq.H 2) and ammonia emission suppression (<0.5 ppm) were achieved using a 2-mol/L AB aqueous solution adding into citric acid powder (molar ratio of AB: citric acid = 1:1). In contrast, the amount of hydrogen release at other concentrations and/or using the mixing method was below 2.7 mol/mol AB within several hours. Ammonia re-released even after hydrogen release in the case of high AB concentration (e.g. >4 mol/L AB aqueous solution with citric acid powder (molar ratio of AB: citric acid = 1:1)) in the solution because of formation of borate ester (1:2 borate–diol molar ratio) via mono-ammonium citrate (a borate-ester precursor), which was revealed by the solution NMR. These results reveal a cost-effective and simple on-way method for hydrogen release with suppressed impurities. Furthermore, understanding impurity generation mechanisms can contribute to utilizing AB-derived hydrogen. [Display omitted] • H 2 and NH 3 release from citric acid-catalyzed AB hydrolysis was evaluated by continuous measurement. • The theoretical maximum H 2 release and NH 3 suppression were achieved. • NH 3 release from ammonia borane was started after 5 h from the start of reaction. • The delayed NH 3 release was caused by the formation of borate ester. [ABSTRACT FROM AUTHOR]

Organophosphate pesticides (OPPs) are widely prevalent in the environment primarily due to their low cost and extensive use in agricultural lands. However, it is estimated that only about 5% of these applied pesticides reach their intended target organisms. The remaining 95% residue linger in the environment as contaminants, posing significant ecological and health risks. This underscores the need for materials capable of effectively removing, recovering, and recycling these contaminants through adsorption processes. In this research, adsorbent materials composed of electro-spun carbon nanofibers (ECNFs) derived from polyacrylonitrile was developed. The materials were characterized through several techniques, including scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Fourier Transform Infrared Spectroscopy (FTIR), Brunauer-Emmett-Teller (BET) analysis, and contact angle measurements. SEM analysis revealed details of the structural properties and inter-fiber spacing variations of the carbon nanofibers. The results revealed that ECNFs possess remarkable uniformity, active surface areas, and high efficiency for adsorption processes. The adsorption studies were conducted using batch experiments with ethion pesticide in aqueous solution. High-Performance Liquid Chromatography-Diode Array Detector (HPLC-DAD) was utilized to quantify the concentrations of the OPP. Various parameters, including adsorbent dosage, pH, contact time, and initial ethion concentration, were investigated to understand their impact on the adsorption process. The adsorption isotherm was best described by the Freundlich model, while the kinetics of adsorption followed a non-integer-order kinetics model. The adsorption capacity of the ECNFs for OPP removal highlights a significant advancement in materials designed for environmental remediation applications. This study demonstrates the potential of ECNFs to serve as effective adsorbents, contributing to the mitigation of pesticide contamination in agricultural environments. [ABSTRACT FROM AUTHOR]

Electrocatalytic reduction of CO2 powered by renewable electricity provides an elegant route for converting CO2 into valuable chemicals and feedstocks, but normally suffers from a high overpotential and low selectivity. Herein, Ag and Sn heteroatoms were simultaneously introduced into nanoporous Cu (np‐Ag/Sn−Cu) mainly in the form of an asymmetric local electric field for CO2 electroreduction to CO in an aqueous solution. The designed np‐Ag/Sn−Cu catalyst realizes a recorded 90 % energy efficiency and a 100 % CO Faradaic efficiency over ultrawide potential window (ΔE=1.4 V), outperforming state‐of‐the‐art Au and Ag‐based catalysts. Density functional theory calculations combined with in situ spectroscopy studies reveal that Ag and Sn heteroatoms incorporated into Cu matrix could generate strong and asymmetric local electric field, which promotes the activation of CO2 molecules, enhances the stabilization of the *COOH intermediate, and suppresses the hydrogen evolution reaction, thus favoring the production of CO during CO2RR. [ABSTRACT FROM AUTHOR]

A new amphiphilic boron-dipyrromethene (BODIPY) dye bearing a hydrophobic 2,3,4-tris(n-dodecyloxy) phenyl group at the meso-position and two hydrophilic cationic moieties at the boron was synthesized. This dye exhibited kinetically controlled and thermodynamically controlled aggregation pathways in aqueous solution, leading to the formation of two types of J-aggregates, i.e., the metastable Agg. I and thermodynamically more stable Agg. II. Further kinetic analysis of the spontaneous transformation from Agg. I to Agg. II indicated that Agg. I was an off-pathway aggregate species. Moreover, both Agg. I and Agg. II displayed J-aggregate characteristics with enhanced fluorescence quantum yields and shortened fluorescence lifetime with respect to that of the monomeric dye. In particular, Agg. II exhibited a narrowed and intense J-band, reflecting the strong excitonic coherence in the aggregate. Morphological studies revealed that Agg. I consisted of spherical nanoparticles, while Agg. II had a multilamellar vesicular structure. In addition, in the fluorescence spectra of Agg. I and Agg. II, an unexpected broad band at longer wavelength than that of the J-aggregate emission was observed, which could be ascribed to the possible formation of excimers in these J-aggregates in aqueous solution. [ABSTRACT FROM AUTHOR]

Mn3[Fe(CN)6]2 (MnHCF) selectively adsorbs methanol from water with a distribution coefficient of 11 mL g−1, which is 3–11 times that of activated carbons and zeolites. MnHCF exhibits an adsorption capacity of 0.36 mmol g−1 and can adsorb 1000 mg MeOH per L in aqueous solution, demonstrating its effectiveness for treating methanol-contaminated wastewater. [ABSTRACT FROM AUTHOR]

Summary The study explored the combination effect between of green tea extract (GTE) and black rice extract (BRE) and the encapsulation process of the co‐extract. A 2:1 (w/w) ratio of GTE to BRE in citric aqueous solution at pH 6 showed the highest antioxidant activity (IC50 = 0.306 mg mL−1) with the strongest incremental effect (combination index = 0.547). It exhibited potent anti‐inflammatory effects, with sirtuin 1 enzyme‐stimulating activity (28.593 of fluorescent intensity) and NF‐κB protein suppression in RAW 264.7 macrophages (57.76% at 100 μg mL−1). Freeze‐dried double emulsion encapsulated powder (CEP) with the highest encapsulation efficiency (73.38%) and total polyphenol content (218.28 mg GAE g−1) was prepared using a lecithin to O phase ratio of 2:25 (w/w) and a chitosan‐carboxymethyl cellulose to W1/O emulsion phase ratio of 1:1 (w/w). Our findings suggest utilising CEP as a compound in functional food by contributing to improved health and well‐being. [ABSTRACT FROM AUTHOR]

Background Methods Results Conclusions Sensitive skin is a highly prevalent problem. The objective of the study was to assess whether the tested products are effective and safe in terms of improving the symptoms of sensitive skin.A clinical randomized split‐face study was carried out on 24 healthy female subjects. Three cosmetic combinations were tested versus vehicle: product A (Solía Thermal Spring Water–TSW–from Cantabria, Spain + diatom algae–P. tricornutum–extract), product B (Solía TSW + diatom algae extract + Annona cherimola Fruit Extract) and product C (Solía TSW + diatom algae extract + Annona cherimola Fruit Extract + niacinamide). Prior to each application of the study Product (A, B, or C)/vehicle, 10% of aqueous solution of capsaicin to induce skin irritation was applied, mimicking the symptoms of sensitive skin. Stinging and burning sensations were evaluated at different time points.All three tested products A, B, and C showed to act better in calming the symptoms induced by capsaicin when compared to the vehicle.The tested products would be an interesting option for treating stinging and burning sensations in sensitive skin patients. [ABSTRACT FROM AUTHOR]

The preparation of scaffolds that are both macroporous and mechanically strong is a significant challenge in the development of bioactive ceramic materials for bone substitution. Furthermore, the introduction of beneficial extra-functionalities such as bacterial inhibition is highly appealing but adds complexity to implant design and production. In this study, we aimed to fabricate highly porous, bioactive and antibacterial glass-ceramic scaffolds with interconnected macropores through the foam replica method. The scaffolds were sintered at two different temperatures (620 and 850 °C), yielding glassy or partially crystallized materials, respectively. The scaffold produced at higher temperature was found to be highly porous (>75 vol%), mechanically stronger and able to induce hydroxyapatite formation after three days of soaking in SBF (in vitro bioactivity). In order to confer antibacterial activity, silver (Ag) ions were introduced onto the scaffold surface through ion exchange in an aqueous solution. Compositional analysis confirmed the successful doping of the scaffold surface with silver, which was continuously released in SBF for at least 28 days, as revealed by ICP-MS. Finally, the antibacterial action of the Ag-doped scaffold was confirmed towards Staphylococcus epidermidis. Overall, the results reported in this work show the potential of foam-like Ag-doped bioactive glass-ceramic scaffolds to be used in applications requiring bone substitution and antibacterial properties. [ABSTRACT FROM AUTHOR]

The evaluation of the adsorption capacity of amine‐functionalized silica coated iron oxide magnetic particles (Fe3O4/SiO2‐NH2) as a highly recyclable adsorbent for Congo Red (CR) and Eriochrome Black T (EBT) azo‐dyes from water is reported. The Fe3O4/SiO2‐NH2 were prepared by a simple co‐precipitation method of iron oxide (Fe3O4) nanoparticles followed by silica coating on oleic acid coated Fe3O4. A series of investigation was performed to assess the various experimental parameters like contact time (0–360 min), pH (3–10), stirring speed (0–500 rpm), adsorbent dosages (0.02–0.12 g) and initial concentrations (0.02–0.15 mg mL−1) of dyes. According to the Langmuir isotherm, the maximum adsorption capacities of CR and EBT on Fe3O4/SiO2‐NH2 particles were found to be 211.86 mg g−1 and 81.98 mg g−1, respectively. In comparison, the pseudo‐second order model provided adsorption capacities of 200.40 mg g−1 for CR and 80.91 mg g−1 for EBT. Additionally, the maximum adsorption amounts of CR and EBT on Fe3O4/SiO2‐NH2 particles were 179.37 mg g−1 and 75.43 mg g−1, achieved within 300 min and 180 min at pH 3, respectively. The dye‐loaded particles were recoverable for CR and EBT removal by simple regeneration with 0.1 molL−1 NaOH solution to use the particles until more than five cycles. [ABSTRACT FROM AUTHOR]

Reaction of a P/N/S hybrid ligand dpppyatc (N,N‐bis((diphenylphosphaneyl)methyl)‐N‐(pyridin‐2‐yl)‐amino‐thiocarbamide) with Au(tht)Cl (tht=tetrahydrothiophene) and [Cu(MeCN)4]BF4 afforded cluster complex [Au2Cu(dpppyatc)2](BF4)2Cl (1). Upon excitation at 480 nm, 1 emitted orange phosphorescence at 646 nm, which was red‐shifted to ~698 nm selectively in the presence of ammonia or amine vapor. This chromic photoluminescent response toward ammonia was sensitive and reversible. Complex1 could detect ammonia in aqueous solution down to concentrations of 2 ppm (w/w). [ABSTRACT FROM AUTHOR]

Due to the challenge of cleaving O−O bonds at single Co sites, mononuclear Co complexes typically show poor selectivity for the four‐electron (4e−) oxygen reduction reaction (ORR). Herein, we report on selective 4e− ORR catalyzed by a Co porphyrin with a hanged ZnII ion. Inspired by Cu/Zn‐superoxide dismutase, we designed and synthesized 1‐CoZn with a hanging ZnII at the second sphere of a Co porphyrin. Complex 1‐CoZn is much more effective than its Zn‐lacking analogues to catalyze the 4e− ORR in neutral aqueous solutions, giving an electron number of 3.91 per O2 reduction. With spectroscopic studies, the hanging ZnII was demonstrated to be able to facilitate the electron transfer from CoII to O2, through an electronic "pull effect", to give CoIII‐superoxo. Theoretical studies further suggested that this "pull effect" plays crucial roles in assisting O−O bond cleavage. This work is significant to present a new strategy of hanging a ZnII to improve O2 activation and O−O bond cleavage. [ABSTRACT FROM AUTHOR]

This account summarizes the impact that the quest for sustainability is having on the field of organic polyconjugate molecules and polymers for plastic (opto)electronics. While at the proof-of-concept level, the design criteria as well as the preferred synthetic strategies to access new and improved materials have been dominated by the need for performance. The ongoing transition from the lab environment to the industrial scale imposes strict limitations on the cost and overall environmental impact of new materials. We here summarize our efforts on the development of new design criteria and synthetic strategies aimed at improving sustainability – without compromising performance – in organic polyconjugated molecules. The article is composed of three sections: Introduction and motivation, sustainability through improved synthetic methods and through improved design. Outline 1 Introduction and Motivation 2 Sustainable Reaction Methods 2.1 The New Tools: Reactions in Aqueous Solution of Surfactants 2.2 Intrinsically More Sustainable Reactions: Direct Arylation 2.3 Sustainable Multistep Protocols: Combining Micellar, Solventless, and Mechanochemical Methods 3 Sustainability as a Design Criterion: De Novo Design 4 Conclusion [ABSTRACT FROM AUTHOR]

We present the synthesis of a novel benzimidazolium-based surface active ionic liquid (SAIL), 3-dodecyl-1H-3λ-benzo[d]imidazole chloride, a SAIL with excellent surface activity and self-aggregation tendency whose aqueous micellar solutions offer exceptional solubilizing capacity and electrocatalytic performance for efficient electrocarboxylation of halocarbons. [ABSTRACT FROM AUTHOR]

In this research, graphene oxide (GO) as an adsorbent was used to remove norfloxacin and ceftriaxone antibiotics from aqueous solutions. All environmental factors affecting removal (e.g., pH, adsorbent mass, contact time, and concentration) were optimized in a discontinuous system. The design of experiments and the optimization of variables were carried out using the response surface method (RSM). The results of the analysis of variance (ANOVA) and the regression coefficients of the quadratic terms indicated that the responses were significantly affected by all the studied variables (P < 0.05). Also, the quadratic polynomial model results corresponded to empirical data with a high coefficient of determination (i.e., R² > 0.99 for both antibiotics). Besides, the adjusted R² (R²-adj >0.98 for both antibiotics) was close to R² values, indicating a good and acceptable statistical model. According to the results, the optimal removal of antibiotics by GO occurs in conditions of pH of 8, 0.034 g of the adsorbent mass, a sonication time of 20 min, and a concentration of 25 mg L-1. In these conditions, the maximum removal efficiencies of ceftriaxone and norfloxacin were equal to 95.87% and 98.64%, respectively. GO was recovered in five adsorption/desorption processes, and the removal efficiency declined very slightly after using the adsorbent for five cycles. Therefore, it is concluded that GO is an efficient and acceptable adsorbent for removing ceftriaxone and norfloxacin from aqueous environments. [ABSTRACT FROM AUTHOR]

Binary systems of lanthanide ions (La, Nd, Gd, Ho, Tb, and Lu) with L-malic acid in molar ratios of 1:1 and 1:2 were studied. This study was carried out in aqueous solutions, and the composition of the formed complexes was confirmed using computer data analysis. The overall stability constants of the complexes and the equilibrium constants of the reaction were determined. The effect of ligand concentration on the composition of the internal coordination sphere of the central atom was observed. Changes in the coordination sphere of lanthanide ions were confirmed by spectroscopic measurements. [ABSTRACT FROM AUTHOR]

Hydrophilic and hydrophobic phenomena occur in aqueous solutions. Despite the complex nature of the molecular interactions, the propensity of molecules and ions to hydration is sometimes characterized by a single "hydration number". Passynski's method for determining the hydration numbers in dilute aqueous solutions belongs to the group of methods based on the analysis of the isentropic compressibility of a mixture. Isentropic compressibility is a thermodynamic material constant; thus, the paper deals with Passynski's approach discussed in terms of thermodynamics. First, Passynski's assumptions were applied to the volume of the mixture. Subsequent strict thermodynamic derivation led to a formula for the hydration number which resembled that of Onori rather than the original one. Passynski's number turned out to be inconsistent with the thermodynamics and mechanics of fluids. This is a rather purely empirical measure of the slope of the dependence of isentropic compressibility on the solute mole fraction in a dilute aqueous solution. Being the quotient of the slope and the isentropic compressibility of pure water, Pasynski's numbers are more convenient to analyze and discuss than the slopes themselves. Conclusions about molecular interactions based on these numbers must be treated with considerable caution. [ABSTRACT FROM AUTHOR]

The thermal regeneration of CO2 sorbent is the most energy-consuming step in the CO2-capturing process. Although the addition of an acid can induce CO2 release, it does not regenerate the sorbent because the acid forms a salt with the basic sorbent and diminishes its capability for capturing CO2. In this work, a novel approach based on thermally enhanced acidity was studied. This approach utilizes an additive that does not affect the sorbent at room temperature, but its acidity significantly increases at elevated temperatures, which assists the thermal release of CO2. M-cresol was added to an aqueous solution of morpholine. The CO2 capture and release of the mixture were compared to those of a control solution without m-cresol. The amounts of carbamate, bicarbonate, and unreacted morpholine were quantitatively determined using 1H NMR and weight analysis. The results showed that m-cresol did not affect the reactivity of morpholine in the formation of carbamate with CO2 at room temperature. At elevated temperatures, the acidity of m-cresol increased according to Van't Hoff's equation, which resulted in a significantly higher rate of CO2 release than that of the control. Given the low cost of m-cresol and its derivatives, this approach could lead to practical technology in the near future. [ABSTRACT FROM AUTHOR]

We utilize molecular dynamics simulations to investigate the microstructures of ions and polyelectrolytes in aqueous solutions under external electric fields. By focusing on the multi-body interactions between ionic components and H2O molecules, as well as their responses to the external electric fields, we clarify several nontrivial molecular features of the ionic and polyelectrolyte solutions, such as the solvations of cations and anions, clustering of the ions, and dispersions/aggregations of polyelectrolyte chains, as well as the corresponding responses of H2O molecules in these contexts. Our simulations illustrate the variations in structures of ionic solutions caused by reversing the charge sign of the ions, and elucidate the disparity in structures between anionic and cationic polyelectrolyte solutions in the presence of the external electric fields. This work clarifies the mechanism for the alternations in complex multi-body interactions in aqueous solutions caused by the application electric field, which can contribute to the fundamental understanding of the physical and chemical natures of ion-containing and charged polymeric systems. [ABSTRACT FROM AUTHOR]

BACKGROUND Microneedling is used to enhance transcutaneous drug delivery. However, the extent to which microneedling devices impact filler delivery and whether this varies by filler type, microneedling device type, and treatment sequence is not known. OBJECTIVE To histologically assess and quantify the delivery of commonly used fillers through microneedling, using both a microneedling pen and a microneedling roller. In addition, the authors investigated whether there is a variation in filler delivery based on the sequence of microneedling in relation to topical filler application. METHODS Ex vivo human abdominal skin samples were subjected to microneedling pen or microneedling roller treatment. Black tissue marking ink, hyaluronic acid, poly-L-lactic acid, or undiluted calcium hydroxyapatite was topically applied before or immediately after microneedling treatment. RESULTS Histological evaluation revealed a notable presence of black ink within channels formed by both microneedling treatments (15.5%--98.1%), whereas there was limited presence of the various filler types tested (0%--6.6%) in all settings. Topical application before microneedling treatment led to relatively higher filler/ink deposition within the channels formed by the microneedling treatments compared with topical application after microneedling. CONCLUSION Transcutaneous delivery of fillers was not significantly helped by microneedling treatment, whereas the microneedling devices demonstrated effective delivery of an aqueous solution. [ABSTRACT FROM AUTHOR]

• Iron addition raised the removal efficiency of ciprofloxacin from 65 to 94%. • Electro-activated persulfate (EAP) with iron addition process is cost-effective. • EAP+Fe process is superior to EAP for ciprofloxacin removal. • Three ciprofloxacin intermediates were reported for the first time in this study. Ciprofloxacin (CIP) is a commonly used antibiotic in the fluoroquinolone group and is widely used in medical and veterinary medicine disciplines to treat bacterial infections. When CIP is discharged into the sewage system, it cannot be removed by a conventional wastewater treatment plant because of its recalcitrant characteristics. In this study, boron-doped diamond anode and persulfate were used to degrade CIP in an aquatic solution by creating an electrochemically activated persulfate (EAP) process. Iron was added to the system as a coactivator and the process was called EAP+Fe. The effects of independent variables, including pH, Fe2+, persulfate concentration, and electrolysis time on the system were optimized using the response surface methodology. The results showed that the EAP+Fe process removed 94% of CIP under the following optimum conditions: A pH of 3, persulfate/Fe2+ concentration of 0.4 mmol/L, initial CIP concentration 30 mg/L, and electrolysis time of 12.64 min. CIP removal efficiency was increased from 65.10% to 94.35% by adding Fe2+ as a transition metal. CIP degradation products, 7 pathways, and 78 intermediates of CIP were studied, and three of those intermediates (m/z 298, 498, and 505) were reported. The toxicological analysis based on toxicity estimation software results indicated that some degradation products of CIP were toxic to targeted animals, including fathead minnow, Daphnia magna, Tetrahymena pyriformis , and rats. The optimum operation costs were similar in EAP and EAP+Fe processes, approximately 0.54 €/m3. [Display omitted] [ABSTRACT FROM AUTHOR]

A systematic experimental density and sound velocity measurement was carried out for imidazolium-based ionic liquids (ILs) in pure water and in aqueous solutions of 0.03 w/w of water-miscible polymers with different structures and molar masses at T= (288.15, 293.15, 298.15, 303.15 and 308.15) K and p = 84.5 kPa. The ILs under investigation are 1-butyl-3-methylimidazolium hydrogen sulphate ([C4mim][HSO4]) and 1-butyl-3-methylimidazolium bromide ([C4mim]Br). The effects of temperature, polymer type, and IL anion type on the various volumetric and compressibility properties, such as apparent molar volume, isentropic compressibility, apparent molar isentropic compressibility, and infinite dilution apparent molar properties for transfer of ILs from water to aqueous polymer solution were scrutinised. From the gathered results, ion-water interactions, ion-ion interactions at finite concentration, and water-structure breaking character for aqueous solutions of [C4mim][HSO4] are more considerable than aqueous solutions of [C4mim]Br. However, [C4mim]Br-polymer interactions are more favourable than interactions between [C4mim][HSO4] and the studied polymers. [ABSTRACT FROM AUTHOR]

The current article has identified dual solutions and their stability for the Ti-alloy/water nanofluid over an exponentially shrinking sheet, while taking into consideration the presence of magnetic fields, radiation and thermal buoyancy forces. The Tiwari and Das model has been utilised to formulate mathematical equations, which have subsequently been transformed from partial differential equations to ordinary differential equations using suitable similarity transformations. The transformed equations have been solved using the shooting method incorporated with the Runge–Kutta technique. Through the application of these techniques, it has been ascertained that multiple solutions have emerged for this problem. To assess the stability of these solutions, the eigenvalue approach has been employed. The eigenvalue approach has revealed that only the first solution is physically viable in laboratory settings, while the second solution is not. The effects of radiation on temperature, skin friction, velocity and heat transfer rate have been elaborated upon in detail. Furthermore, flow separation points have been identified and the rationale behind the delay in flow separation has been expounded upon. Streamlined patterns have been drawn and explained to enhance our understanding of the fluid flow behaviour. Finally, it is worth noting that these types of studies have significant applications in the medical and aerospace industries. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study is to prepare a new adsorbent activated carbon immobilized on polystyrene (ACPS) for uranium (VI) and thorium (IV) removal from an aqueous solution. Activated carbon (AC) was derived from biochar material by chemical activation to increase the active sites on its surface and enhance the adsorption capacity. Activated carbon (AC) was immobilized on polystyrene (PS) to improve the physical properties and facilitate separation from the working solution. A feasibility study for the adsorption of uranium (VI) and thorium (IV) on the new adsorbent (ACPS) has been achieved. Adsorption kinetics, isotherms, and thermodynamics models of the adsorption process were used to describe the reaction mechanism. Design/methodology/approach: Activated carbon was synthesized from biochar charcoal by 2 M H2SO4. Activated carbon was immobilized on the pretreatment polystyrene by hydrothermal process forming new adsorbent (ACPS). Characterization studies were carried out by scanning electron microscope, energy-dispersive X-ray spectrometer, infrared spectroscopy and X-ray diffraction techniques. Different factors affect the adsorption process as pH, contact time, solid/liquid ratio, initial concentration and temperature. The adsorption mechanism was explained according to kinetic, isothermal and thermodynamic studies. Also, the regeneration of spent ACPS was studied. Findings: The experimental results showed that pH and equilibrium time of the best adsorption were 6.0 and 60 min for U(VI), 4.0 and 90 min for Th(IV), (pHPZC = 3.4). The experimental results fit well with pseudo-second order, Freundlich and Dubinin–Radushkevich models proving the chemisorption and heterogenous adsorption reaction. Adsorption thermodynamics demonstrated that the adsorption process is exothermic and has random nature of the solid/liquid interface. In addition, the regeneration of spent ACPS research showed that the adsorbent has good chemical stability. According to the comparative study, ACPS shows higher adsorption capacities of U(VI) and Th(IV) than other previous bio-adsorbents. Originality/value: This study was conducted to improve the chemical and physical properties of bio-charcoal purchased from the local market to activated carbon by hydrothermal method. Activated carbon was immobilized on polystyrene forming new adsorbent ACPS for eliminating U(VI) and Th(IV) from aqueous solutions. [ABSTRACT FROM AUTHOR]

Industrialization increases day by day and hence the demand of Cr (VI) compounds are also increased in tanning, electroplating, printing and in dyeing industries, which has resulted in considerable amounts of waste containing Cr(VI) being emitted. Environmental scientists are quite concerned about how much Cr(VI) is present in water since it creates a severe harm to the ecosystem and humans. Because of their functional diversity, high efficacy, economic viability, and simplicity of technical operation, low-cost biosorbents made of lignocellulosic biomasses have drawn attention for elimination of Cr(VI). One versatile and efficient approach to address Cr(VI) pollution is through the use of lignocellulosic materials, for biosorption. Within this comprehensive review, we conduct an impartial evaluation of the biosorption capabilities of various lignocellulosic biosorbents, while also examining the underlying mechanisms involved in the biosorption process by focusing on crucial variables including pH, contact time, dosage, and temperature. In addition, we assemble a list of investigated lignocellulose-based biosorbents that may be beneficial. In addition to offering our recommendations for future views, the review's objective is to highlight existing trends, potential study areas, and obstacles to the practical use of the biosorption process. [ABSTRACT FROM AUTHOR]