High Ion Concentration Research Articles

Ferro-ionic states and domains morphology in HfxZr1−xO2 nanoparticles

Unique polar properties of nanoscale hafnia-zirconia oxides (HfxZr1−xO2) are of great interest for condensed matter physics, nanophysics, and advanced applications. These properties are connected (at least partially) to the ionic–electronic and electrochemical phenomena at the surface, interfaces, and/or internal grain boundaries. Here, we calculated the phase diagrams, dielectric permittivity, spontaneous polar, and antipolar ordering, as well as the domain structure morphology in HfxZr1−xO2 nanoparticles covered by ionic–electronic charge originating from surface electrochemical adsorption. We revealed that the ferro-ionic coupling supports the polar long-range order in nanoscale HfxZr1−xO2, induces, and/or enlarges the stability region of the labyrinthine domains toward smaller sizes and smaller environmental dielectric constant at low concentrations of the surface ions. The ferro-ionic coupling causes the transition to the single-domain ferro-ionic state at high concentrations of the surface ions. We predict that the labyrinthine domain states, being multiple-degenerated, may significantly affect the emergence of the negative differential capacitance state in the nanograined/nanocrystalline HfxZr1−xO2 films.

Hydrogen Bonding-Driven Adaptive Coacervates as Protocells.

Coacervation based on liquid-liquid phase separation (LLPS) has been widely used for the preparation of artificial protocells and to mimic the dynamic organization of membrane-free organelles. Most complex synthetic coacervates are formed through electrostatic interactions but cannot withstand high ionic strength conditions (>0.1 M). Alternative components and driving forces are highly desired for the formation of natural organelles to overcome the drawbacks of traditional coacervates. Herein, hydrogen bonding-driven adaptive coacervates are reported via the complexation of poly(ethylene glycol) (PEG) and tannic acid (TA). The LLPS behavior of these adaptive coacervates is dependent on the concentration and mass ratio of PEG and TA, which can be used to tune the size of coacervates ranging from 70 nm to 10 μm as well as the morphology of isotropic particles and hollow capsules. Coacervates are stable at high ionic concentrations up to 1 M and can serve as protocells to mimic cellular behaviors including metabolism (e.g., nutrient uptake), phagocytosis, and membrane fusion. The reported approach provides a platform for the rational design of hydrogen bonding-driven coacervates with controllable size and morphology, offering potential applications in protocell construction and therapeutic delivery.

Insight into the roles of Cl− for the degradation of acid Red 14 in an electrochemical advanced oxidation system: Mechanisms and DFT studies

Textile wastewater was typically characterized by high concentrations of chloride ions, with Acid Red 14 (AR14) representing a significant pollutant. Nevertheless, research into the degradation of AR14 by electrochemical advanced oxidation processes (EAOPs) had largely overlooked the influence of chloride ions. In this regard, the EC-Clorine-MMO/Ti system was designed, and the degradation mechanism of AR14 was subjected to meticulous investigation. The adopted anode was composed of Ti/IrO2-Ta2O5 (mixed metal oxide, MMO). It demonstrated superior efficiency in degrading AR14 within a sodium chloride (NaCl) electrolyte, registering an apparent kinetic constant rate approximately 16.76 times greater than that observed within a sodium perchlorate (NaClO4) electrolyte. The optimal chloride ion concentration was identified as 0.04 mol/L. Besides, alkaline conditions were not conducive to the degradation of AR14. It was noteworthy that the electrochemical byproducts chlorite (ClO2−), chlorate (ClO3−), perchlorate (ClO4−), and trihalomethane (THMs) were not produced in the solution treated by the EC-Clorine-MMO/Ti system. Electron paramagnetic resonance (EPR) spectroscopy, probe, and quenching experiments identified that hydroxyl radicals (•OH), superoxide radicals (O2•−), and dichloride radicals/chlorine monoxide radicals (Cl2•−/ ClO•) were the major reactive species. Of these, •OH played a pivotal role in AR14 degradation. Additionally, the three principal degradation pathways of AR14 were deduced by LC-MS analysis, UV–vis spectra, density-functional theory (DFT) calculations, and excitation-emission matrix (EEM) fluorescence spectroscopy. Furthermore, the generation mechanism of reactive species and the proposed mechanism of AR14 degradation by the EC-Clorine-MMO/Ti system were presented. The study made a significant contribution to the understanding of the electrochemical reactions occurring in textile wastewater and provided valuable insights into the rational control of electrolytic conditions for the treatment of saline wastewater.

Electrochemical-thermal-mechanical overcharge model on a scale of particle for lithium-ion batteries

During overcharging of lithium-ion batteries, lithium plating can occur on the anode surface when the maximum lithium intercalation concentration is exceeded, while the cathode is in a lithium-poor state, which can result in shortened battery lifespan and safety. In this work, the geometric structure of the positive electrode particles is designed based on the tomography data, while the negative electrode particles are represented by spheres with different sizes. The homogenization method is used, with the carbon filler, binder and electrolyte regarded as a single porous conductive adhesive domain. Based on the main mechanism of lithium-ion battery overcharge, a coupled three-dimensional electrochemical-mechanical-thermal overcharge model on a particle scale is developed for NCM cathode and graphite anode. The coupled mathematical model consists of four parts, namely the electrochemical model, the lithium plating model, the thermal model and the stress-strain model. In terms of lithium precipitation, the particle radius parameter and charging rates are investigated. The results show that the lithium plating concentration of the particles near the separator is higher, following the “principle of proximity” , namely the sequence of lithium deintercalation is related to the migration path. The surface of anode particles with small particle size is more prone to lithium precipitation due to the high maximum lithium ion concentration on the surface of the particles, the low surface lithium precipitation overpotential, and the high average Von Mises stress. At high charging rate, fast charge transfer rate and ion diffusion rate result in a low voltage at the anode, triggering off lithium precipitation. At a low rate, polarization and low temperature can lead to the precipitation of more lithium on the surface of the anode particles. In terms of stress, the spatial distribution between particles and thermal effects are investigated. The ratio of the distance from the contact surface to the center of the particle to the particle radius is calculated and defined as the contact depth (<inline-formula><tex-math id="M2">\begin{document}$Jr$\end{document}</tex-math></inline-formula>), in order to better describe the law of particle contact stress. It is shown that the contact depth between particles is inversely proportional to the stress on the contact area. When the heat generation effect is considered, the temperature of the battery rises faster with the increase of the charging rate. The electrochemical parameters related to temperature and the lithium concentration diffusion gradient increase significantly, and the influence of temperature on the particle stress is also more significant. The relevant results can provide theoretical basis and guidance for designing battery and optimizing charge strategies.

Impact of Wood Smoke Exposure on Aortic Valve Mineralization: Microvesicles as Mineral Conveyors in Patients with Coronary Stenosis.

Background: Aortic valve calcification results from degenerative processes associated with several pathologies. These processes are influenced by age, chronic inflammation, and high concentrations of phosphate ions in the plasma, which contribute to induce mineralization in the aortic valve and deterioration of cardiovascular health. Environmental factors, such as wood smoke that emits harmful and carcinogenic pollutants, carbon monoxide (CO), and nitrogen oxide (NOx), as well as other reactive compounds may also be implicated. The purpose of this research was to study the impact of wood smoke on specific aortic valve characteristics, including lesion size and percentage of mineralization, in patients with aortic valve stenosis (AS). Methods: This observational study included 65 patients who underwent primary valve replacement surgery at the National Institute of Cardiology, 11 of whom were exposed to wood smoke. For each patient, approximately 0.5 cm of aortic valve tissue was collected along with a blood sample anticoagulated with sodium citrate. The valves were analyzed using scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM-EDS). Since extracellular microvesicles (MVs) may induce epigenetic changes in target cells by transferring their cargo, we also analyzed their mineral content. Results: Individuals exposed to wood smoke exhibit more extensive lesion (835 µm2) characteristics compared to those with no exposure (407.5 µm2). Interestingly, FESEM images of MVs showed the presence of minerals on their surface, thus providing evidence on their possible role in the pathophysiology of mineralization. Conclusions: Our study uniquely demonstrates imaging-based evidence of structural damage and mineralization in aortic valve tissue, with chronic wood smoke exposure emerging as a significant causative factor.

Crack Sealing in Concrete with Biogrout: Sustainable Approach to Enhancing Mechanical Strength and Water Resistance.

Concrete, as the most widely used construction material globally, is prone to cracking under the influence of external factors such as mechanical loads, temperature fluctuations, chemical corrosion, and freeze-thaw cycles. Traditional concrete crack repair methods, such as epoxy resins and polymer mortars, often suffer from a limited permeability, poor compatibility with substrates, and insufficient long-term durability. Microbial biogrouting technology, leveraging microbial-induced calcium carbonate precipitation (MICP), has emerged as a promising alternative for crack sealing. This study aimed to explore the potential of Bacillus pasteurii for repairing concrete cracks to enhance compressive strength and permeability performance post-repair. Experiments were conducted to evaluate the bacterial growth cycle and urease activity under varying concentrations of Ca2+. The results indicated that the optimal time for crack repair occurred 24-36 h after bacterial cultivation. Additionally, the study revealed an inhibitory effect of high calcium ion concentrations on urease activity, with the optimal concentration identified as 1 mol/L. Compressive strength and water absorption tests were performed on repaired concrete specimens. The compressive strength of specimens with cracks of varying dimensions improved by 4.01-11.4% post-repair, with the highest improvement observed for specimens with 1 mm wide and 10 mm deep cracks, reaching an increase of 11.4%. In the water absorption tests conducted over 24 h, the average mass water absorption rate decreased by 31.36% for specimens with 0.5 mm cracks, 29.06% for 1 mm cracks, 27.9% for 2 mm cracks, and 28.2% for 3 mm cracks. X-ray diffraction (XRD) and scanning electron microscopy (SEM) analyses confirmed the formation of dense calcium carbonate precipitates, with the SEM-EDS results identifying calcite and vaterite as the predominant self-healing products. This study underscores the potential of MICP-based microbial biogrouting as a sustainable and effective solution for enhancing the mechanical and durability properties of repaired concrete.

Destruction Of C7, C9 Perfluorocarboxylic Acids By The Strain Ensifer Adhaerens M1

The aim of the study was to determine the resistance to high concentrations of fluoride ions in the environment of the strain Ensifer adhaerens M1 isolated from soil at a fire extinguishing agent storage and testing site, to determine the growth kinetics and destruction of C7, C9 perfluorocarboxylic acids, perfluoroheptanoic acid and perfluorononanoic acid, respectively, as the sole sources of carbon and energy. The degradation products of perfluorinated carboxylic acids were identified using LCMS-IT-TOF. It was found that the degradation process occurs in multiple stages leading to the formation of perfluorohexanoic acid and accompanied by the release of fluoride ions. Strain Ensifer adhaerens M1 is resistant to F- up to a concentration of 150 mg/L in the environment. Within 14 days of cultivation, bacteria completely utilized perfluoroheptanoic acid and perfluorononanoic acid. Based on chromatography-mass spectrometry and ion chromatography data, a scheme for the stepwise degradation of the investigated perfluorinated acids involving the enzymes coded by novR and dhlA genes is proposed.

Sustainable supercapacitors using advanced hydrated amino acid ionic liquids: A novel approach to biodegradable energy storage

In this work, we explore the concepts of molecular dynamics (MD) to investigate the energy storage capacity of supercapacitors (SCs) composed of amino acid-based ionic liquids (AAILs) as pure and hydrated electrolytes, and graphene electrodes. The choice to use AAILs is motivated by environmental concerns, as these compounds are biodegradable. We focused our efforts on models composed of 1-ethyl-3-methylimidazolium (emim) combined with alanine (ala), valine (val), leucine (leu), and isoleucine (ile). Furthermore, we aimed to optimize the biodegradable properties by considering different hydration levels of the electrolyte. We analyzed the models subjected to hydration in proportions of 10 %, 20 %, 30 %, 40 %, and 90 %. This research addresses the lack of detailed studies on the effect of hydration on AAIL electrolytes in supercapacitors, evaluating their impact on energy storage and electric double layer (EDL) formation, and highlights the potential of AAILs as electrolytes for supercapacitors, offering a biodegradable option for energy storage without a loss of efficiency. The results obtained showed capacitances between 2.29 and 2.71 µF/cm2, and gravimetric energy densities ranging from 4.4 to 4.8 J/g for electrolytes with high ion concentrations, and from 6.5 to 6.8 J/g for devices with low ion concentration electrolytes. These values indicate excellent potential for application in the context of energy storage, reinforcing the viability of AAILs as an environmentally friendly and efficient solution for supercapacitors.

The effect of ion solvation on ion-induced nucleation—A generalized Thomson model

We present a model for ion-induced nucleation, focusing on the effect of dissociated ions embedded in the fluid surrounding a charged core or colloid. The model includes the ions' direct electrostatic energy and preferential solvation. The integrated ions' free energy has two terms: The first can be short- or long-range, depending on their density. The second is proportional to the nucleus' volume and can shift the state from undersaturation to supersaturation at high ion concentration. The inclusion of the Gibbs transfer energies of ions in the free energy leads to a modified Poisson-Boltzmann equation for the potential around the core. The integrated ions' free energy is added to the fluids' interfacial and bulk terms to establish a generalized Thomson model. In the Debye–Hückel limit, the model is solved analytically, while in the nonlinear regime, it is solved numerically. The state diagram in the plane of saturation and core charge includes regions with a homogeneous phase, electro-prewetting, metastable vapor, metastable nucleus, and spontaneous nucleation states. The lines separating these regions depend sensitively on the preferential solvation. Our model shows nucleation asymmetry to the sign of the nucleus' charge. This sign asymmetry is due to the Gibbs transfer energies of ions.

Novel cationic and amphoteric starch-modified coagulants for efficient treatment of relatively high turbidity and large organic matter source waters: Performance, predictive modeling and mechanism analysis

Finding alternative solutions of water source containing short-term relative high turbidity and large organic content is a pressing need in view of the inherent limitations of traditional inorganic coagulants. Requirement of significant dosage increase for conventional iron and aluminum salt coagulants can create several challenges including dose adjustment, suboptimal performance and high concentration of residual metal ions. In this study, acrylamide monomer (AM) and methacryloyloxyethyltrimethylammonium chloride (DMC) were grafted onto starch and carboxymethyl starch to obtain novel cationic and amphoteric starch-modified coagulants. Concurrently, the obtained coagulants were comprehensively evaluated under varying simulated water quality conditions to analyze their turbidity and organic matter removal efficiencies. Polymerized aluminium chloride (PACl) was used as the reference coagulant to evaluate the roles of polymer charge density, total charge, and molecular chain length in the coagulation mechanism for further illustration of their efficacy. In comparison to the traditional coagulant PACl, the modified coagulant was found to be more effective in enhancing flocculation and aggregation behavior, lowering of energy barriers, and enhancing adsorption energy by using the Density Functional Theory (DFT) calculations and Extended Derjaguin-Landau-Verwey-Overbeek (XDLVO) theory based investigation of the mechanism. Moreover, these behaviors were mainly attributed to significant exchange of charge density between coagulant and the pollutants. Additionally, in order to facilitate accurate and efficient treatment of water having diverse qualities, quadratic polynomial equation based mathematical model was constructed for quantitative analysis and model prediction. Findings of this study point towards an effective and precise approach to coagulation technology and thereby enabling sustainable and efficient purification of turbid source water containing large organic matter.

Stability and structure of aqueous Sb (III) chloride complexes from 25 °C to 250 °C at 25 MPa at high chloride ion concentrations

Stability and structure of aqueous Sb (III) chloride complexes from 25 °C to 250 °C at 25 MPa at high chloride ion concentrations

Co-Ion Identity Affects Double Layer Structure and Reactivity Trends in the Hydrogen Evolution Reaction

The formation of an electric double layer is ubiquitous in electrolytes undergoing electrochemical reactions. Currently, models for the double layer rely on the assumptions of dilute electrolyte theory where ions in solution do not interact. Dilute electrolyte theory predicts that solely hydrated counterions, or ions opposing the surface charge, occupy the near surface region and impact reactivity. Since this theory does not account for conditions like high applied potentials and high ion concentrations, understanding the relationship between double layer structure and electrochemical reactivity is critical for opening new domains for electrochemical modulation.Notably, our recent work shows that co-ions, or ions with the same charge as the surface, can also have a definitive influence on reaction rates, particularly under conditions of high applied potential and large bulk ion concentrations. In this talk, I will discuss how to use the hydrogen evolution reaction as a model system to explore co-ion effects in electrocatalytic reactions. In our work, we systematically vary co-ion identity and track hydrogen evolution reactivity as a function of concentration to highlight how the co-ion becomes increasingly relevant in the concentrated regime. In particular, we highlight the unique ability of the tetrafluoroborate co-ion to undergo dynamic ligand exchange between hydroxide and fluoride. This allows tetrafluoroborate to act as a hydroxide sink to stabilize the hydrogen evolution byproduct. Furthermore, I will discuss our use of Raman spectroscopy to describe how co-ions impact interfacial hydrogen bonding networks, which can have a significant impact on aqueous electrochemistry. Our results highlight how co-ions influence double layer structures and have significant implications for tuning other aqueous reactions such as carbon dioxide and nitrate electroreduction.

Quantification and Correction of Impedance Effects on Square Wave Voltammetry for High-Concentration Soluble-Soluble Reactions

Molten salts are of interest for a wide variety of applications including nuclear energy, metal electrorefining, and concentrated solar power. In situ monitoring of species within molten salts is important to ensure operation is well-controlled. Electroanalytical techniques such as square wave voltammetry (SWV) and linear sweep voltammetry (LSV) offer approaches toward precise measurement of species’ fundamental properties (e.g. diffusion coefficient, number of electrons transferred, etc.). However, several publications have reported deviations between data collected through SWVs and LSVs. In this talk, we explain the discrepancy in the context of SWV using molten chloride systems with dissolved metal ions. Theoretical simulations coupled with experimental data confirm the divergence of property measurements can be attributed to impedance effects. Using our approach, the diffusion coefficients, solubility limits, and concentration measurements at high concentrations of metal ions extracted using SWV converged with literature reports using LSVs.

An ultra-low fouling electrochemical mocularly imprinted sensor based on size exclusion effect for highly selective pentachlorophenol detection

Pentachlorophenol (PCP) is considered as a highly toxic pollutant in water environment. However, detecting low concentrations of PCP precisely hindered by various interferences is still a tough challenge. In this study, an antifouling electrochemical molecularly imprinted (E-MIP) sensor harnessing the size exclusion effect was specifically designed for highly selective detection of PCP in water. The distinctive interaction between the size-selective poly-hydroxyproline helical peptide (PHHP) and poly(o-phenylenediamine) (p(o-PD)) molecularly imprinted films, strongly reduced non-specific adsorption. In the face of high concentrations of organic matters and ions, the reported sensor exhibited robust antifouling capabilities that it preserved 90 % of the initial signal. In addition, the limit of detection (LOD) reached an exceptionally low level of 1.13 nM (S/N = 3), spanning a wide linear range from 1 nM to 10 μM, and the sensor showed high selectivity with an impressive imprinted factor of 12.01 for PCP. Meanwhile, it owned great repeatability and reproducibility, long-term stability for PCP detection within 25 days, and decent reusability (retaining 92.33 % of its senor performance after 5 cycles), which ensured its excellent feasibility for determination of PCP in complex water samples with co-existing interferences due to acceptable recoveries. The development of this strategy provides an innovative platform for PCP quantification in real water samples, underscoring its potential as a key tool in managing PCP at relevant sites.

Spatiotemporal distribution in chemical composition of wet atmospheric deposition in Bandung Indonesia.

Bandung, Indonesia, represents the complex interactions between climate variability, basin topography, and deposition processes. This study conducted a long-term spatiotemporal analysis, including pH distribution and pollutant accumulation monitoring, to observe the chemical composition of wet deposition in Bandung as part of the Acid Deposition Monitoring Network in East Asia (EANET). The results revealed that and were the predominant ions, followed by , with their distribution varying across different sites due to local emissions and atmospheric processes. The interactions between these ions, particularly the formation of secondary inorganic aerosols such as ammonium sulfate and ammonium nitrate, were closely linked to the basin's localized sources and topographical features. Areas experiencing high traffic congestion were classified as acidic regions due to their low pH levels. In contrast, a rural site exhibited a basic pH due to the high concentration of ion . Variations in pH and conductivity, along with the impacts of climatic events such as El Niño and La Niña, emphasized the role of weather patterns in shaping wet deposition dynamics. Seasonal trends indicated elevated total ion concentrations during the dry season, driven by sea salt contributions, as supported by strong correlations between Na+ and and between Na+ and Mg2+. Additionally, geological materials and atmospheric reactions contributed to the strong correlations observed between soil-derived cations and acidic species. The increasing trend in and the contrasting decrease in concentrations in rural areas suggest evolving emission sources and environmental conditions.

High-pressure homogenization assisted pH-shifting modified soybean lipophilic protein interacting with chitosan hydrochloride: Double emulsion construction, physicochemical properties, stability, and in vitro digestion analysis

This study was aimed to improve ability of soybean lipophilic protein (LP) to stabilize W/O/W emulsions. LP modified through high-pressure homogenization assisted pH-shifting, then modified LP-chitosan hydrochloride (MLP-CHC) complexes were prepared, which used stabilize W/O/W emulsions. Multispectral techniques unveiled that high-pressure homogenization assisted pH-shifting attenuated vibrational frequency of N-H in LP and expose more hydrophobic residues. According to molecular docking, MLP and CHC formed covalent complexes through electrostatic attraction and improved ability to stabilize the interface. The W/O/W emulsion using high-pressure homogenization assisted base-shifting LP (11LP) had a smaller particle size (9.96 μm), higher absolute potential (46.96 mV) and interfacial adsorbed protein (67.02%). Meanwhile, MLP-CHC complexes allowed the W/O/W emulsion to form stronger network structure and exhibit stronger stability in acidic, alkaline, thermal and high ionic concentration environments. The in vitro digestion showed that W/O/W emulsion could effectively protect the bioactivity of vitamin B12 and vitamin E during the digestion process, and realize their efficient delivery. This study offers theoretical reference for constructing of protein-polysaccharide-based functional emulsion transport systems for food industry.

A one-step polyvinyl alcohol/polyacrylamide/polyacrylic acid/dimethyl sulfoxide/CaCl2 hybrid hydrogel enabling anti-fatigue, anti-freeze and anti-dehydration for wearable strain sensor

Hydrogel with fatigue resistance, freezing tolerant and dehydration resistance are peculiarly attractive in strain sensors. The hydrogel soaked in organic solvent is an effective strategy to improve freezing resistance and dehydration resistance, while this may result in poor conductivity. Moreover, ion-incorporation is considered to be the most feasible method for solving above concern, while high concentration of salt ions will result in weak mechanical properties. Therefore, the facile preparation of anti-freezing and anti-dehydration hydrogels with excellent fatigue resistance remains a challenge. Herein, a polyvinyl alcohol/polyacrylamide/polyacrylic acid/dimethyl sulfoxide/CaCl2 hybrid hydrogel was designed and fabricated through a facile one-step method to balance a variety of outstanding properties. On account of the hybridization design of multi-materials, the hybrid hydrogel exhibited high ionic conductivity (∼0.2 S/m), strength (∼0.36 MPa) and stretchability (∼825 %). Meanwhile, the hybrid hydrogel demonstrated prominent freezing resistance, dehydration resistance and fatigue resistance. The mechanical properties almost no deterioration after 1000 stretching cycle at 100 % strain, exposure to environment for 30 days or freeze at low temperature. Besides, the hybrid hydrogel-based stain sensor showed a linear sensitivity (GF = 1.12 over 0–400 % strain), quickly responsivity (200 ms), and could monitor various human activities steadily, demonstrating distinguished potential for use in wearable health monitoring and flexible electric skins.

Hierarchically-porous resin for the adsorption of organic matter in raffinate produced by solvent extraction from the vanadium industry

Solvent extraction wastewater contains high concentrations of organic pollutants and metal ions, making it difficult to treat. This paper presents a method of using hierarchically-porous adsorption resin to recover organics from raffinate and regenerate the resin, addressing secondary pollution in extraction processes. The chosen resin, WS6108, removes over 95 % of organics from raffinate, with high metal ion concentrations enhancing its adsorption efficiency. The article conducted an optimization experiment and mechanism study on WS6108 resin for adsorbing organic matter in vanadium raffinate (OIVR), followed by desorption and recycling tests. Results showed WS6108 resin achieved a 96.7 % adsorption efficiency at a solid–liquid ratio of 24 g/L after optimization. The chosen methanol desorbent achieves over 99 % desorption efficiency for the WS6108 cycle under specific conditions. The resin’s performance remains stable for up to 45 cycles. Adsorption isotherms and kinetic experiments indicate that OIVR adsorption by WS6108 resin is endothermic, non-spontaneous and entropy increasing. Moreover, the adsorption kinetics of OIVR by WS6108 resin followed a pseudo-second-order model, based on the activation energy, liquid film diffusion was considered the main rate-controlling step. A column experiment was conducted to verify that WS6108 resin can be used in real vanadium raffinate to remove organics. Density functional theory (DFT) revealed that strong hydrogen bonding, π-π stacking and excellent adsorption diffusion behavior drive OIVR adsorption. This study aims to increase the use of adsorption to treat oily wastewater generated by solvent extraction.

PH monitoring in high ionic concentration environments: performance study of graphene-based sensors.

Graphene-based pH sensors, acclaimed for their exceptional sensitivity to environmental variations, have garnered significant interest in scientific research. However, the sensor performance in high ionic concentration environments is limited, due to the Debye length ion screening effect. In this study, an innovative graphene channel pH sensing device was developed and modified by cross-linked poly(methyl methacrylate) (PMMA). Furthermore, even in high ionic concentrations, the pH value can be precisely measured by this sensor. The sensor has remarkable sensitivity, and high response rate of - 70.49mV/pH within the pH range from 7 to 10. Notably, the sensors retain uniform response direction and sensitivity under different ionic concentrations environmental and maintain consistent reversibility and stability. This advancement in sensor technology paves the way for broader applications in complex ionic environments.

Investigating the effect of finite ionic size and solvent polarization on induced charge electro-osmosis around a perfectly polarizable cylinder

Many industrially relevant microfluidic applications use concentrated solutions of macro-molecular solutes dissolved in polar solvents like water, which are typically deployed at high voltages. In this study, we investigate the effect of finite ionic sizes and solvent polarization on induced charge electro-osmotic flow around a perfectly polarizable cylinder, at high electric field strengths and ionic concentrations. The flow is actuated by means of a direct current electric field, and the step response of various flow parameters are studied numerically. Finite ionic sizes, defined through a steric factor ν, are modeled using the modified Poisson–Nernst–Planck model. Additionally, a field-dependent permittivity, characterized by a solvent polarization number A, accounts for molecular re-orientation effects. Our findings reveal an ion-size modulated decrement in charge concentration in the electrical double layer and an augmentation in the electric field. Remarkably, the resulting flow velocities increase with ion size. Solvent polarization, on the other hand, results in a marked reduction in flow velocities. Steric effects, however, dominate over a large range of parameter space (applied voltage and bulk ionic concentration) as compared to solvent polarization. Finally, we demonstrate that unequal ionic sizes result in flow asymmetries at the steady-state, thereby generating net electro-phoretic motion of suspended particles.