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In this work, the vapor-liquid equilibrium behavior of aqueous ternary systems composed of choline chloride (ChCl) and imidazolium-based ionic liquids has been investigated using the isopiestic method at 25 °C. The ionic liquids used are 1-butyl-3-methylimidazolium bromide ([C4mim][Br]) and 1-butyl-3-methylimidazolium trifluoromethane sulfonate ([C4mim][CF3SO3]). The effect of ionic liquid anion on water activity, vapor pressure, and isopiestic equilibrium concentrations has been evaluated. The deviation of water iso-activity curves from the linear isopiestic relation has been used as a benchmark to unveil the salting-out or salting-in effect of ChCl on the aqueous solution of ionic liquids. The results show that ChCl plays the role of co-solvent in the studied systems and increases the solubility of the ionic liquids in water, indicating the occurrence of the salting-in phenomenon. [ABSTRACT FROM AUTHOR]

[Display omitted] Establishing alternative methods for freshwater production is imperative to effectively alleviate global water scarcity, particularly in land-locked arid regions. In this context, extracting water from the ubiquitous atmospheric moisture is an ingenious strategy for decentralized freshwater production. Sorption-based atmospheric water harvesting (SAWH) shows strong potential for supplying liquid water in a portable and sustainable way even in desert environments. Herein, the latest progress in SAWH technology in terms of materials, devices, and systems is reviewed. Recent advances in sorbent materials with improved water uptake capacity and accelerated sorption–desorption kinetics, including physical sorbents, polymeric hydrogels, composite sorbents, and ionic solutions, are discussed. The thermal designs of SAWH devices for improving energy utilization efficiency, heat transfer, and mass transport are evaluated, and the development of representative SAWH prototypes is clarified in a chronological order. Thereafter, state-of-the-art operation patterns of SAWH systems, incorporating intermittent, daytime continuous and 24-hour continuous patterns, are examined. Furthermore, current challenges and future research goals of this cutting-edge field are outlined. This review highlights the irreplaceable role of heat and mass transfer enhancement and facile structural improvement for constructing high-yield water harvesters. [ABSTRACT FROM AUTHOR]

Adenosine triphosphate (ATP) is an extremely important bio-molecule, which plays a crucial role in various biological processes by releasing the energy stored in it. Thus, abnormal ATP concentration in the body can hamper normal biological activities, which can ultimately lead to serious physiological disorders. Therefore, fast, label-free methods such as fluorescence-based methods for ATP quantification are highly necessary. Herein, we report a supramolecular assembly of a dansylated gemcitabine derivative (GEM-DNS) and cationic detergent cetyltrimethylammonium bromide (CTAB) as a turn-on fluorescence probe for ATP quantification. Similar to free dye solution, the combination of 0.25 mM CTAB with an aqueous dye exhibits very feeble emission, but the dye-surfactant mixture displays dramatic enhancement in fluorescence intensity with an increase in the ionic strength of the solution. This prompted the utilization of the dye-CTAB mixture for the detection of ATP at physiological pH. ATP, owing to its high negative charge density, efficiently induces aggregation to the cationic CTAB molecules. These newly formed aggregates encapsulate the dye into their hydrophobic cavities leading to the formation of a GEM-DNS@CTAB@ATP ternary complex, which eventually results in a significant surge in the fluorescence intensity of the bound dye. This fluorescence enhancement is directly proportional to ATP concentration in the dynamic range of 0 to 4.5 μM, allowing us to quantify ATP with a limit of detection of ∼0.25 μM in a buffer. Furthermore, the turn-on signal for the GEM-DNS@CTAB complex is found to be highly selective towards ATP, enabling its quantification even in diluted human serum samples. Consequently, our system provides a novel and promising platform for ATP quantification owing to its several advantages such as a large Stokes shift, high signal-to-noise ratio, low background, high brightness, and minimum possibility of false signals. [ABSTRACT FROM AUTHOR]

Cu(In, Ga)(S, Se)2 (CIGSSe) solar cell is one of the most promising thin‐film solar cells with a record power conversion efficiency (PCE) of 23.6%. Conventional CIGSSe thin‐film solar cells are usually fabricated on Mo‐coated soda‐lime glass substrate, thereby, the sunlight on the rear side cannot be utilized by the monofacial CIGSSe solar cells owing to the opacity of the Mo electrode. CIGSSe solar cells fabricated on transparent conductive oxide (TCO) electrode enable to fabricate bifacial solar cells, which can generate power on both sides of solar cells, so that bifacial solar cells have a high potential application in building‐integrated photovoltaics. However, the PCEs of CIGSSe solar cells fabricated on TCO substrates are significantly lower than those of ones on Mo substrates. In this article, bifacial CIGSSe solar cells on fluorine‐doped tin oxide (FTO) substrate are fabricated by using an ionic liquid‐assisted solution approach and utilizing a MoO3 thin film as an interface layer between FTO and CIGSSe absorber layer, yielding a front‐side PCE of 9.73% and a back‐side PCE of 1.77%. [ABSTRACT FROM AUTHOR]

Protein extraction from silk is a unique area of research and the foremost need is the efficient extraction of the silk proteins namely fibroin and sericin from the silk fibres, which is conventionally done using chemicals. In this work, we show that Ionic liquids (ILs) can be employed as a green and alternative method for degumming sericin from both mulberry (B. mori) and non‐mulberry (A. assamensis and P. ricini) silk. Six different ILs with varying tail lengths were studied for their degumming efficiencies. The interaction between silk proteins and IL ions involves a complex ionic disruption of hydrogen bonds, non‐polar interactions, and electrostatic effects. We have found that 1‐Butyl‐3‐methylimidazolium chloride (BMIM.Cl), 1‐ethyl‐3‐methylimidazolium tetrafluoroborate (EMIM.BF4) and Tetraethylammonium bromide (TEAB) bring in higher weight loss % in silk fibres compared to other ILs, indicating that it can be used in better sericin removal without significant damage to the silk fibre. TEAB emerged as a potential candidate for sericin extraction due to its promotion of protein destabilization. Additionally, no drastic changes in the structure of the extracted silk protein sericin were observed, as evident from the FTIR spectra and SEM images. This work highlights for the first time, the use of ILs for extraction of non‐mulberry silk sericin and also proves that ILs can be a potential green solvent for sericin extraction. [ABSTRACT FROM AUTHOR]

The commercially available magnetic nanoparticles (MNPs) in the solid powder form are typically colloidally unstable under the aqueous environment and can easily settle out without modification. Thus, surface functionalization with polyelectrolyte is required to improve the colloidal stability of MNP systems prior to their applications. In this study, the effect of various factors during the functionalization process, including type of polyelectrolyte, solution pH, ionic strength and particle-to-polyelectrolyte ratio, on the colloidal stability of the functionalized MNPs was evaluated experimentally and theoretically. It was revealed that PSS-70 k and PDDA(M) imparted better colloidal stability toward the functionalized MNPs as compared to PEG, PSS-1000 k and PDDA(L). The optimal pH to produce PSS-70 k- and PDDA(M)-functionalized MNPs is found to be pH 3 and 11, respectively. In addition, the optimum MNP/polyelectrolyte mass ratio was revealed to be 1:5 and 1:0.5 for the synthesis of PSS-70 k- and PDDA(M)-functionalized MNP systems, respectively. The colloidal stability of both PSS-70 k- and PDDA(M)-functionalized MNPs was severely impeded by the presence of free ionic species in the solution during the functionalization process. Lastly, the mathematical analysis based on DLVO theory was consistent and well aligned with the experimental findings. [ABSTRACT FROM AUTHOR]

We demonstrate the facile fabrication of metal-wire-embedded microtrenches interconnected with semiconducting ZnO nanowires (ZNWs) through the continuous mechanical machining of micrograting trenches, the mechanical embedding of solution-processable metal wires therein, and the metal-mediated hydrothermal growth of ZNWs selectively thereto. The entire process can be performed at room or a very low temperature without resorting to vacuum, lithography, and etching steps, thereby enabling the use of flexible polymer substrates of scalable sizes. We optimize the fabrication procedure and resulting structural characteristics of this nanowire-interconnected flexible trench-embedded electrode (NIFTEE) architecture. Specifically, we carefully sequence the coating, baking, and doctor-blading of an ionic metal solution for the embedding of clean metal wires, and control the temperature and time of the hydrothermal ZNW growth process for faithful interconnections of such trench-embedded metal wires via high-density ZNWs. The NIFTEE structure can function as a bending-sensitive optoelectronic sensor, as the number of ZNWs interconnecting the neighboring metal wires changes upon mechanical bending. It may benefit further potential applications in diverse fields such as wearable technology, structural health monitoring, and soft robotics, where bending-sensitive devices are in high demand. [ABSTRACT FROM AUTHOR]

The side reactions in seawater and the sedimentation of the photocatalyst in highly concentrated ionic solutions seriously affect the activity and stability of the photocatalyst to split seawater to produce hydrogen. In terms of these problems, we designed the super-hydrophilic mesoporous brookite/anatase TiO 2 photocatalyst accordingly. The characterization results of crystal phase and band structure confirmed that the transition from brookite/rutile type I hetero-phase junction to brookite/anatase type II hetero-phase junction. Without any sacrificial agents, the photocatalytic H 2 production rate from seawater splitting reached 6.59 mmol g−1 h−1, which was 2.5 times and 2.9 times higher than brookite/rutile TiO 2 and anatase/rutile TiO 2 (P25), respectively. Meanwhile, it was also 4.4 times, 11.8 times and 36.1 times higher than brookite, anatase and rutile nanoparticles. Furthermore, the contact angle test confirmed the superhydrophilicity of the photocatalyst, mitigating the side reactions induced by Cl− and ensuring the long-term stability (100 h) of the photocatalyst in seawater. [Display omitted] • A nanoscale super-hydrophilic mesoporous brookite/anatase TiO 2 was precisely synthesized. • The transition from type I hetero-phase junction to type II hetero-phase junction was realized. • Photocatalytic H 2 production rate from seawater splitting reached 6.59 mmol g−1 h−1. • Hydrophilicity enhanced the activity and stability of the photocatalysts in seawater. [ABSTRACT FROM AUTHOR]

Phosphogypsum (PG) is an industrial by-product of the transformation of phosphate rocks. For decades, PG has been a source of environmental concern due to the massive amount produced thus far, i.e., 7 billion tons, with a current production rate of 200–280 million tons per year. Phosphate minerals contain various impurities that precipitate and concentrate within PG. These impurities hinder PG usability in various sectors. This paper aims to purify PG using an innovative process based on staged valorization of PG. Initially, PG dissociation by ethylenediaminetetraacetic acid (EDTA) was optimized. After screening of different parameters and monitoring the ionic conductivity of solutions, it was disclosed that a pH-dependent solubilization process in the presence of EDTA resulted in high solubility of PG, up to 11.82 g/100 mL at pH > 11. Subsequently, a recovery of the purified PG by selective precipitation of calcium sulfate dihydrate (CSD) from obtained filtrate through pH adjustment to 3.5 were investigated. An abatement of 99.34% Cr, 97.15% Cd, 95.73% P2O5, 92.75% Cu, 92.38% Al2O3, 91.16% Ni, 74.58% Zn, 72.75% F, 61.43% MgO, 58.8% Fe2O3, 56.97% K2O, and 55.41% Ba was achieved. The process relied on the variation of EDTA chelation properties towards monovalent, divalent, and trivalent cations at different pHs. According to the findings of this study, a staged purification process in the presence of EDTA is an effective method for removing impurities from the industrial PG. [ABSTRACT FROM AUTHOR]

The process of countercurrent multistage precipitation (CnMP) was developed for reduction of the acidic variant (av) content in monoclonal antibody (mAb) pools. The process was performed in polyethylene glycol (PEG) solutions of low ionic strength, at which av was the most prone to precipitate. To design the process, a mathematical model was formulated, which consisted of steady-state mass balance equations and underlying thermodynamic dependencies. The model was solved for different combinations of the process variables, including the protein concentration in the feed material and the PEG concentration in subsequent precipitation stages. The model solution was projected onto two-dimensional planes, where the performance indicators, such as the separation yield and the av reduction level, were correlated with the process variables. CnMP overperformed crosscurrent multistage precipitation (CsMP) and ion exchange chromatography (IEX) used in previous studies; in the comparison with CsMP, the 3-stage CnMP process allowed up to 28% increase in yield and up to 25% increase in the av reduction level, and in the comparison with IEX, up to 37% increase in yield and up 12.5% increase in the av reduction level. The yield benefit of CnMP depended on the composition of the feed material and the demand for the av reduction. The concept was experimentally verified; the 2- and 3-stage CnMP processes were performed using the input process variables provided by the model solution. The performance indicators calculated by the model and experimentally measured were in a good agreement, which indicated both feasibility and predictability of CnMP. [Display omitted] • PEG-aided precipitation was used to reduce acidic variant content in a mAb pool. • Precipitation was performed in crosscurrent (CsMP) and countercurrent (CnMP) regimes. • Mathematical model was used for the process design. • CnMP outperformed CsMP and ion exchange chromatography. • CnMP can be performed in continuous mode. [ABSTRACT FROM AUTHOR]

The experimental study of the DNA interaction with three cadmium coordination compounds [Cd(phen)3](CH3CO2)2, [Cd(phen)2(H2O)2](CH3CO2)2, and [Cd2(phen)4(H2O)2](CH3CO2)4 was carried out using spectrophotometry, viscosity, and dynamic light scattering methods. The role of the solution ionic strength (concentration of NaCl) was analyzed. All compounds can penetrate (fully or partly) to the major or minor DNA grooves. It was shown that, in addition to the important role of electrostatic interactions in the formation of the complex, intercalation of the 1,10-phenanthroline ligand occurs for compounds [Cd(phen)2(H2O)2](CH3CO2)2 and [Cd2(phen)4(H2O)2](CH3CO2)4. Compound [Cd(phen)3](CH3CO2)2 binds to DNA externally. The coordination bond between cadmium and DNA was formed in DNA complexes with [Cd2(phen)4(H2O)2](CH3CO2)4. Preliminary computer modeling of the DNA interaction with the compounds used was performed. [ABSTRACT FROM AUTHOR]

[Display omitted] Electrochemical impedance spectroscopy (EIS) constitutes a useful tool in membrane science and technology because it provides valuable structural and functional information. The different arcs observed in the impedance spectra permit to decouple and understand distinct physico-chemical phenomena occurring under operating conditions. By using EIS techniques, we have characterized here multipore asymmetric membranes with conical pores that exhibit a broad range of ionic conduction properties, including current rectification. These properties can be modulated by tuning the electrical interaction between the charges functionalized on the pore surface and the nanoconfined ionic solution. In particular, the membrane electrical response is studied as a function of the amplitude and frequency of the external voltage signal, the electrolyte type and concentration, and the solution pH. Remarkably, significant chemical inductance effects are observed. The scalability and biocompatibility of these pores suggest good potential for use in hybrid biodevices and interfaces. [ABSTRACT FROM AUTHOR]

Earth pressure balance (EPB) shield tunneling in coastal silty clay strata often faces the problems of clogging on the screw conveyor or the belt conveyor due to lumps of clay soils formed because of the large cohesion of clay particles. Soil conditioning using common foaming agents is not enough to alleviate the problem. Therefore, the novel dispersed foaming agent was studied in this work using performance and orthogonal compound tests. The foam microstructure was observed using an electron microscope to analyze the evolution mechanism of bubbles for different additives. Both laboratory and in situ tests were carried out to assess the effectiveness of the novel dispersed foaming agents. The testing results showed that 50 vol.% is an optimum foaming injection ratio to improve rheological properties and undrained shear strength of silty clay to avoid the unnecessary waste of conditioning materials. The half-life time (T1/2) and foam expansion ratio (FER) of novel foaming agents using the formation ionic solution as the solvent increased due to existing hydrophilic polar groups based on undisturbed soil samples taken from a Xiamen Metro construction site. It was shown that acids, alkalis, and salt ions had little effect on the FER and T1/2 of foaming agents (Foams A and B) using the macromolecular dispersant. The variations in the plasticity index were similar to those of the liquid limit for the muck conditioned using dispersed foaming agents with sodium citrate, sodium bicarbonate, and sodium chloride at a concentration of 0.1 wt%. Sodium bicarbonate had the most significant impact on the foaming agents' anticlay effect. Compared with commercial and house-made foaming agents of the Fuzhou Metro project, the muck was effectively conditioned by Foams A and B based on the slump and temperature values. In addition, the average cutter-head torque was reduced by about 250 kN·m. The amount of foaming agents used was reduced by about 18.6% and 12.9% on average in the two testing sites, respectively. [ABSTRACT FROM AUTHOR]

This study explores the efficacy of 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide and 1-hexyl-3-methylimidazolium chloride as cleaning agents for aged cellulosic artifacts. A 10% v/v acetone solution of these ionic liquids (ILs) effectively removes the brownish-yellow color of aged paper in a 10 min immersion treatment. Colorimetric analysis shows a remarkable increase in lightness (L*) by up to 40% and a decrease in red/brownish tones (b*) after IL treatment. The cleaning process also deacidifies the paper, shifting the pH to neutral-slightly basic levels and enhancing its long-term stability. Optimal pH outcomes are achieved, with ionic liquid consumption values of 0.4–0.6 g/g of paper. The FTIR analysis revealed structural changes in cellulose induced by the washing step, which is mainly due to the reorganization effect imparted by the ionic liquids. Furthermore, ILs mobilized degraded compounds and acidic species, aiding in their extraction during the restoration process. Mechanical testing indicated an enhancement in the overall tensile strength and strain at break values for IL-treated papers by up to 33%. This study demonstrates the multiple benefits of alkylimidazolium ionic liquids for preserving and restoring cultural heritage artifacts made of cellulosic materials. [ABSTRACT FROM AUTHOR]

The adoption and evolution of water molecules and ions in mixed electrolytes at the surface play vital roles in the physical properties and chemical reactions of SiO2-like corrosion. The effect of salt type and concentration on the structure and dynamics of water molecules and ions at silica surfaces are studied using all-atom molecular dynamics simulations taking the case of the NaCl, MgCl2, and NaCl–MgCl2 aqueous solutions. The ability of ion hydration is in the order of Mg2+ > Na+ > Cl−, being opposite to their hydration Gibbs free energies, which directly influence the weak interaction in the solution and the diffusion rate of the particles. Mg shows stronger destruction to weak interactions than Na does, and ionic hydration of Mg2+ decelerates the self-diffusion coefficient of water molecules significantly due to the enhanced Coulomb effect and the interruption of solution continuity. Meanwhile, the self-diffusion coefficient of particles decreases with the concentration improvement in the single salt solution as increased ionic hydration. In the mixed salt solution, the order of diffusion rate is Cl− > Na+ > Mg2+ as a result of the different confinement effects of the protonated pore. Interestingly, a small amount of Na+ addition can promote the self-diffusion of Mg2+, but a great many of Na+ addition slows the diffusion of Mg2+. This work provides comprehensive insight into the behavior of mixed salt solutions at silica surfaces, shedding light on the practical applications of geological sciences, cultural relics protection, and colloidal sciences. [ABSTRACT FROM AUTHOR]

We characterize a concentrated 7.3 m CaCl2 solution, combining neutron diffraction with chloride isotopic substitution (Cl-NDIS) in null water and molecular dynamics (MD) simulations. We elucidate the solution structure, thermodynamic properties, and extent of ion pairing previously suggested as concentration-dependent and often not observed at lower concentrations. Our Cl-NDIS measurements designate the solvent-shared ion pairing as dominant and the contact ion pairing (CIP) as insignificant even under conditions close to the solubility limit. The MD models parameterized against neutron diffraction with calcium isotopic substitution (Ca-NDIS) overestimate CIP despite successfully reproducing most of the Cl-NDIS signal. This drawback originates from the fact that Ca2+–Cl− interactions were primarily "hidden" in the Ca-NDIS signal due to overlapping with Ca2+–Ow and Ca2+–Hw contributions to the total scattering. Contrary, MD models with moderate CIP and possessing generally good performance at high concentrations fail to reproduce the NDIS measurements accurately. Therefore, the electronic polarization, introduced in most of the recent MD models via scaling ionic charges, resolves some but not all parameterization drawbacks. We conclude that despite improving the quality of MD models "on average," the question "which model is the best" has not been answered but replaced by the question "which model is better for a given research." An overall "good" model can still be inappropriate or, in some instances, "bad" and, unfortunately, produce erroneous results. The accurate interpretation of several NDIS datasets, complemented by MD simulations, can prevent such mistakes and help identify the strengths, weaknesses, and convenient applications for corresponding computational models. [ABSTRACT FROM AUTHOR]

Thermodiffusion is the migration of a species due to a temperature gradient and is the driving phenomenon in many applications ranging from early cancer detection to uranium enrichment. Molecular dynamics (MD) simulations can be a useful tool for exploring the rather complex thermodiffusive behavior of species, such as proteins and ions. However, current MD models of thermodiffusion in aqueous ionic solutions struggle to quantitatively predict the Soret coefficient, which indicates the magnitude and direction of species migration under a temperature gradient. In this work, we aim to improve the accuracy of MD thermodiffusion models by assessing how well different water models can recreate thermodiffusion in a benchmark aqueous NaCl solution. We tested four of the best available rigid non-polarizable water models (TIP3P-FB, TIP4P-FB, OPC3, and OPC) and the commonly used TIP3P and SPC/E water models for their ability to predict the inversion temperature and Soret coefficient in 0.5, 2, and 4M aqueous NaCl solutions. Each water model predicted a noticeably different ion distribution yielding different inversion temperatures and magnitudes of the Soret coefficient. By comparing the modeled Soret coefficients to published experimental values, we determine TIP3P-FB to be the water model that best recreates thermodiffusion in aqueous NaCl solutions. Our findings can aid future works in selecting the most accurate rigid non-polarizable water model, including water and ion parameters for investigating thermodiffusion through MD simulations. [ABSTRACT FROM AUTHOR]

The effect of resting time on the rheological properties of cement suspensions is generally explained by early formed structure and overconsumption of polycarboxylate superplasticizers (PCEs). In this paper, we propose that the influence of resting time on the rheological properties is closely related to size variation of non‐absorbed PCE. To identify this, glass bead suspensions were prepared with various amounts of PCE and ionic solution, and their rheological properties were evaluated at various times. We found that the yield stress increases with time at higher PCE concentrations and higher ionic strength solutions. Adsorbed PCE during resting tends to bridge the particles rather than disperse them. In addition, it was found that hydrodynamic radius of PCE increased with resting time, and depletion forces resulting from non‐absorbed PCE size changes correlate well with the increased yield stress. [ABSTRACT FROM AUTHOR]

Due to its sensitivity to molecular interactions between functional groups of molecules and ions, vibration spectroscopy is the most tool for studying speciation in nonaqueous solutions. In this paper, vibrational spectra of ionic solutions filled with nanosized oxides have been studied. Solvated cations, anions, SSIPs, and CIPs have been detected, and their concentrations have been determined with due regard for equilibria existing in the solvent. It has been established that all the particles that exist in the solutions of lithium perchlorate in dimethyl sulfoxide are also present in filled solutions, but their relative amount varies. The course of the revealed changes in the number of particles in the systems under study does not allow us to identify the character of the effect of the solid filler field on the particles in the solution. There is no evidence of adsorption of dimethyl sulfoxide or anions on aluminum oxide. [ABSTRACT FROM AUTHOR]

A coordination compound of iron(III) ion with 1,10-phenanthroline, or the oxidized form of ferroin (OFF), which was obtained via the reaction of phenanthroline hydrochloride and iron(III) ammonium sulfate (3:1) in acidic solution and standardized by indirect iodometry, was proposed for use as a titrant for quantitative determination of ascorbic acid (AA) in drugs. The developed method for determining AAwas characterized by satisfactory validation indicators of specificity, linearity (r = 0.990), extended analytical range (50 – 170% AA), accuracy (AA recovery 99.6%), precision (RSD 1.3%), and low relative error of determination (å 2.9%). The procedure for AA analysis using OFF did not depend on the solution pH and ionic strength and enabled titrations in colored and cloudy solutions. The technique was tested on various commercial drugs: 5% AAsolution for injection, Revit drops, AA tablets with glucose, and cinnamon rose hips. [ABSTRACT FROM AUTHOR]

Studies have shown that in an aqueous suspension of inert glass beads, the yield stress is increased as a function of resting time. This study investigates this unexpected phenomenon, focusing on solid surface potentials, PCE size in ionic solutions, and their possible relations to rheological behaviour with resting time. Results indicated that PCE in artificial pore solution will result in a higher yield stress with time. PCE with lower anionic charges and molecular weight can significantly increase the yield stress after 2 h of resting. The absolute value of the zeta potential grows to a certain degree after resting phase. Dynamic light scattering (DLS) results showed that the size of PCE molecules in ionic solutions increases over time, suggesting an enhanced depletion force or bridging force among glass bead particles, which could be the reasons for the increase in yield stress over time. Furthermore, the possible impacts of the depletion force or bridging force resulting from the PCE size change on the rheological properties of cement suspension are discussed. [ABSTRACT FROM AUTHOR]

The main purpose of this study is investigating a reliable and convenient model based on Dickens and Quinby-Hunt approach to predict CH4/CO2 gas hydrate equilibrium temperature in presence of organic inhibitors (e.g., methanol, ethanol, ethylene glycol, triethylene glycol, glycerol), and electrolyte inhibitors (e.g., NaCl, KCl, NaBr, KBr, CaCl2, CaBr2, MgCl2, EMIM-Cl, BMIM-Cl, BMIM-Br, BMIM-I, BMIM-DCA, EMIM-HSO4, EMIM-EtSO4, and EMIM-MeSO4). This model named as Dickens' model is an activity-based model and to calculate water activity of organic solutions the nonrandom two-liquid (NRTL) and Margules was used. Also, Pitzer model was employed to calculate activity of water in electrolyte solutions. A correlation was suggested to determine enthalpy of hydrate dissociation in terms of inhibitor weight percent and equilibrium pressure. Due to no data in open literature, the virial coefficients of Pitzer model in ionic liquid solutions were adjusted. The model results were compared with available experimental data from open literature and observed to be in good agreement with the reported literature. [ABSTRACT FROM AUTHOR]

Hypothesis: Foam is not only an industrially important form of matter, but also one of soft jammed system such as colloidal suspensions and emulsion suspensions. Since foams are composed of gas bubbles and liquid, it is expected that the coupling of bubbles and liquid strongly affects rheology of foams, which is different from simple liquids. To reveal this coupling effect and considering the importance of foam applications, we studied the scraping of foam by a rigid plate on a substrate. Experiment: We mainly used 5.0 wt% solution of ionic surfactant TTAB (tetradecyltrimethylammonium bromide). We systematically investigate the scraping behaviors by the rigid plate as a function of scraping velocity, gap height, confinement length, amount of foam and wettability of the substrate. Findings: The results show that there are three distinguishable scraping patterns: homogeneous scraping, no scraping, and slendered scraping. These behaviors are clearly different from those of simple liquid systems. Of these, the upper limit of homogeneous scraping could be explained theoretically by the competition between dewetting and shear, which is not previously discussed. Furthermore, the theory is applicable to the scraping of other soft jammed systems such as colloidal and emulsion suspensions. [ABSTRACT FROM AUTHOR]

Lithium, as a green energy metal used to promote world development, is an important raw material for lithium-ion, lithium–air, and lithium–sulfur batteries. It is challenging to directly extract lithium resources from brine with a high Mg/Li mass ratio. The microstructure study of salt solutions provides an important theoretical basis for the separation of lithium and magnesium. The changes in the hydrogen bond network structure and ion association of the Li2SO4 aqueous solution and Li2SO4-MgSO4-H2O mixed aqueous solution were studied by Raman spectroscopy. The SO42− fully symmetric stretching vibration peak at 940~1020 cm−1 and the O-H stretching vibration peak at 2800~3800 cm−1 of the Li2SO4 aqueous solution at room temperature were studied by Raman spectroscopy and excess spectroscopy. According to the peak of the O-H stretching vibration spectrum, with an increase in the mass fraction of the Li2SO4 solution, the proportion of DAA-type and DDAA-type hydrogen bonds at low wavenumbers decreases gradually, while the proportion of DA-type hydrogen bonds at 3300 cm−1 increases. When the mass fraction is greater than 6.00%, this proportion increases sharply. Although the spectra of hydrated water molecules and bulk water molecules are different, the spectra of the two water molecules seriously overlap. The spectrum of the anion hydration shell in a solution can be extracted via spectrum division. By analyzing the spectra of these hydration shells, the interaction between the solute and water molecules, the structure of the hydration shell and the number of water molecules are obtained. For the same ionic strength solution, different cationic salts have different hydration numbers of anions, indicating that there is a strong interaction between ions in a strong electrolytic solution, which will lead to ion aggregation and the formation of ion pairs. When the concentration of salt solution increases, the hydration number decreases rapidly, indicating that the degree of ion aggregation increases with increasing concentration. [ABSTRACT FROM AUTHOR]

The nucleation kinetics of ice were investigated with four different types of aqueous solutions. The studied aqueous solutions, i.e., sucrose solution, ionic liquid (IL) solution, pyrolysis oil extract (PO) solution, and acetone‐1‐butanol‐ethanol (ABE) solution, were concentrated by batch suspension freeze crystallization. The nucleation kinetics were investigated using a temperature response method which results in data on nucleation rate per crystal. The obtained nucleation rate per crystal value can be used when dimensioning continuous crystallization processes: the nucleation rate per crystal is inversely proportional to the residence time in continuous crystallization. The subcooling degrees for different solutions were in the range of 0.33 °C to 1.89 °C. Aqueous sucrose solutions had the fastest nucleation kinetics. Ice crystallization from non‐ideal aqueous [DBNH][OAc] ionic liquid solutions required higher subcooling degrees and the nucleation rates per crystal were higher as well. Nucleation of ice formed from aqueous pyrolysis oil extract and aqueous ABE solutions occurred at a lower subcooling degree and the obtained nucleation rate per crystal values were lower. [ABSTRACT FROM AUTHOR]

Nowadays, green chemistry is of high priority to avoid devastating circumstances of global warming and environmental contamination. In this regard, a partially-bio-based hardener for epoxy resins was engineered in a greener approach employing microwave irradiation. The conductive star-shaped, oligoaniline (SB-TAH) was synthesized in four main steps: 1) the preparation of tetra-aniline (as the hard segment arm), 2 and3) the synthesis of tetrafunctional star-shaped bio-based core (in two steps) and 4) coupling arms with the core via a divergent approach. Bio-based core (soft segment) has been synthesized through a direct condensation reaction of pentaerythritol / l-lactic acid /succinic acid (stepwise). The chemical structures were characterized by FT-IR, 13C NMR, and 1H NMR. Its performance, as a hardener for bisphenol A-based epoxy resin (EP), has been examined by DSC, TGA, DMTA, and four-prob conductometry. Results showed two curing exotherm peaks at 145 and 160 °C, and the thermal stability of the cured SB-TAH/EP was significantly enhanced. Based on DMTA results, the star-shaped hardener has toughened the network and made it more uniform and homogenous. The star-shaped hardener reveals impressive electrical conductivities in undoped (6.7 × 10− 4) and doped (2.86 × 10− 2) states and can also induce conductivity in the cured media (8.87 × 10− 4). The cured samples with 20% bio-based content, regardless of epoxy resin source, revealed a very good resistance against alkaline, acidic and ionic aqueous solutions as well as nonpolar solvents (i.e., toluene). The star-shaped oligoaniline hardener possesses a prodigious potential for the fabrication of conductive composite, thermal resistance anticorrosive coatings and conductive adhesives. [ABSTRACT FROM AUTHOR]

When selecting a solvent for a given solute, the strongly held idiom "like dissolves like", meaning that polar solvents are used for polar solutes, is often used. This idea has resulted from the concept that most molecular solvents are homogeneous. In a deep eutectic solvent (DES), however, both components can be ionic or non-ionic, polar or non-polar. By tuning the components, DESs can solubilize a wide variety of solutes, often mixing hydrophobic and hydrophilic components, and the mixture can be designed to control phase behavior. The liquids often contain significant short-length order, and preferential solvation of one component often occurs. The addition of small polar molecules such as water or alcohols results in non-homogeneous liquids, which have significantly decreased viscosity and increased ionic conductivity. Accordingly, the areas covered in this special issue focus on structure and dynamics, solvation, the mobility of charged species, and the ability to obtain controllable phase behavior by adding polar diluents or using hydrophobic DESs. [ABSTRACT FROM AUTHOR]

The most intriguing hypothesis explaining many water anomalies is a metastable liquid–liquid phase transition (LLPT) at high pressure and low temperatures, experimentally hidden by homogeneous nucleation. Recent infrared spectroscopic experiments showed that upon addition of hydrazinium trifluoroacetate to water, the supercooled ionic solution undergoes a sharp, reversible LLPT at ambient pressure, possible offspring of that in pure water. Here, we calculate the temperature-dependent signature of the OH-stretching band, reporting on the low/high density phase of water, in neat water and in the same experimentally investigated ionic solution. The comparison between the infrared signature of the pure liquid and that of the ionic solution can be achieved only computationally, providing insight into the nature of the experimentally observed phase transition and allowing us to investigate the effects of ionic compounds on the high to low density supercooled liquid water transition. We show that the experimentally observed crossover behavior in the ionic solution can be reproduced only if the phase transition between the low- and high-density liquid states of water is coupled to a mixing–unmixing transition between the water component and the ions: at low temperatures, water and ions are separated and the water component is a low density liquid. At high temperatures, water and ions get mixed and the water component is a high-density liquid. The separation at low temperatures into ion-rich and ion-poor regions allows unveiling the polyamorphic nature of liquid water, leading to a crossover behavior resembling that observed in supercooled neat water under high pressure. [ABSTRACT FROM AUTHOR]

Living organisms can sense extracellular forces via mechanosensitive ion channels, which change their channel conformations in response to external pressure and regulate ion transport through the cell membrane. Such pressure-regulated ion transport is critical for various biological processes, such as cellular turgor control and hearing in mammals, but has yet to be achieved in artificial systems using similar mechanisms. In this work, we construct a nanoconfinement by reversibly blocking a single nanopore with a nanoparticle and report anomalous and ultra-mechanosensitive ionic transport across the resulting nanoconfinement upon assorted mechanical and electrical stimuli. Our observation reveals a suppressed ion conduction through the system as the applied pressure increases, which imitates certain behaviors of stretch-inactivated ion channels in biological systems. Moreover, pressure-induced ionic current rectification is also observed despite the high ionic concentration of the solution. Using a combined experimental and simulation study, we correlate both phenomena to pressure-induced nanoparticle rotation and the resulting physical structure change in the blocked nanopore. This work presents a mechanosensitive nano-confinement requiring minimal fabrication techniques and provides new opportunities for bio-inspired nanofluidic applications. [ABSTRACT FROM AUTHOR]

Interactions among ions and their specific interactions with macromolecular solutes are known to play a central role in biomolecular stability. However, similar effects in the conformational stability of protein loops that play functional roles, such as binding ligands, proteins, and DNA/RNA molecules, remain relatively unexplored. A well-characterized enzyme that has such a functional loop is Escherichia coli dihydrofolate reductase (ecDHFR), whose so-called M20 loop has been observed in three ordered conformations in crystal structures. To explore how solution ionic strengths may affect the M20 loop conformation, we proposed a reaction coordinate that could quantitatively describe the loop conformation and used it to classify the loop conformations in representative ecDHFR x-ray structures crystallized in varying ionic strengths. The Protein Data Bank survey indicates that at ionic strengths (I) below the intracellular ion concentration-derived ionic strength in E. coli (I ≤ 0.237M), the ecDHFR M20 loop tends to adopt open/closed conformations, and rarely an occluded loop state, but when I is >0.237M, the loop tends to adopt closed/occluded conformations. Distance-dependent electrostatic potentials around the most mobile M20 loop region from molecular dynamics simulations of ecDHFR in equilibrated CaCl2 solutions of varying ionic strengths show that high ionic strengths (I = 0.75/1.5M) can preferentially stabilize the loop in closed/occluded conformations. These results nicely correlate with conformations derived from ecDHFR structures crystallized in varying ionic strengths. Altogether, our results suggest caution in linking M20 loop conformations derived from crystal structures solved at ionic strengths beyond that tolerated by E. coli to the ecDHFR function. [ABSTRACT FROM AUTHOR]

At present, studies on biochar transport have focused on biochar obtained by oxygen-limited pyrolysis, which may differ from conventional biochar produced by incineration in nature. This work investigated the transport and retention mechanisms of three types of oxygen-limited pyrolytic biochar and three types of traditional biochar in saturated porous media. The results showed that the specific surface area of the three oxygen-limited pyrolysis biochar (180–200 m2·g−1) was higher than that of the traditional biochar (50–60 m2·g−1). Therefore, the retention capacity of pyrolytic biochar is strong and the permeability is less than 0.1. The absolute value of the zeta potential of traditional biochar is greater than 30 mV, and the electrostatic repulsion generated is stronger, with a peak penetration rate of 0.16. Moreover, the zeta potential of biochar and traditional biochar is regulated by pH value and ionic strength. In acidic conditions or solutions with high ionic strength, the zeta potentials of the six types of biochar changed to about − 15 mV, and the second minimum value was less than 0, indicating that there was a tendency for sedimentation. This study provides a new perspective for assessing the transport and environmental risks of biochar in the environment. [ABSTRACT FROM AUTHOR]

Using a newly developed thermo-linear swelling test, this work investigated the influence of temperature on shale swelling and shrinkage and Debye-Hückel length alterations within the diffuse double layer. Furthermore, the effect of temperature, dielectric constant of water, and ionic strength of aqueous solutions on the Debye-Hückel length and subsequent shale swelling and shrinkage was explored. It was found that, for dilute solutions, the product of temperature and dielectric constant of water (T×εr) did not considerably change for temperatures ranging from 25°C to 90°C. When shale communicated with 12% and 20% weight by weight (w/w) NaCl and CaCl2 solutions, the percent change in shale shrinkage as temperature incrementally increased from 25°C to 90°C is quite high and cannot be ignored. Results proposed that the dielectric constant of water may have been reduced by both temperature and ionic strength of solution, all of which caused a greater decrease in the Debye-Hückel length and consequent shale shrinkage. As for saturated NaCl and CaCl2 solutions, shale exhibited swelling performance at moderate temperatures (up to 50°C for NaCl and up to 70°C for CaCl2) followed by shrinkage afterward. This could be credited to the development of repulsive forces between similar ions within the diffuse double layer, which may have overwhelmed their electrostatic screening effect on charged clay surfaces. At higher temperatures, the influence of dielectric constant of water on the decreasing Debye-Hückel length may have softened the repulsion action generated by ions. [ABSTRACT FROM AUTHOR]

Morphological evolution and swelling were observed in the zinc phthalocyanine (ZnPc) layer on a quartz crystal microbalance (QCM) sensor treated with annealing. The morphology affects the swelling during analyte injection. The swelling effect can shorten the QCM sensor recovery time. The ZnPc layer was deposited on the surface of the polystyrene/QCM by evaporation technique. The annealing process was conducted for 1 h at 3 temperature variations: 100, 150, and 220 °C. The swelling experiments were carried out by injecting PBS and Tris-HCl solution into the layer. The surface morphology characterization of ZnPc was observed using an SEM/EDX before and after swelling. The morphological evolution from the network into fibers change to disentangled of the ZnPc molecular chain and broke into a shorter fiber. The diffractogram revealed a monoclinic phase for the samples annealed at 100 and 150 °C. On the other hand, the sample annealed at 220 °C showed a triclinic phase. The formation of ZnPc crystal confirms the disordering structure leading to the morphology change. Further, the ZnPc fibers swell after the injection of PBS and Tris-HCl. Tris-HCl injection at high temperature annealing (220 °C) resulted in fiber tattering. Investigations on diffusion mechanisms were conducted by measuring the change in frequency. The ionic strength of the solutions controlled the diffusion. The PBS diffuses faster than the Tris-HCl into the ZnPc layer. [ABSTRACT FROM AUTHOR]

A laboratory procedure has been suggested for determining the concentration of carboxyl groups at the surface of polystyrene microspheres at the latex concentration of a few hundredths of weight percentage (the COOH groups concentration below 4 × 10−4 mol/L). The procedure is based on conductometric and potentiometric titration. The influence of polymer particles concentration in the system, ionic strength of the solution, titration duration, and the system inertness on the obtained values of the carboxyl groups concentration and the determination accuracy have been investigated. [ABSTRACT FROM AUTHOR]

The aim of this work was to create the new biosensor of alanine transaminase (ALT) activity detection in water samples. A platinum disk electrode was used to transduce chemical reactions into amperometry measured signal. Nanosize polyphenylendiamine (PPD) was applied to improve the selectivity of the transducer. In the work, the most effective isomer PD was selected and the stability of the additional membrane based on it was checked. The bioselective element was formed by the immobilization of glutamate oxidase on the surface of the transducer covered by a semipermeable P-meta-PD membrane. There was reported the method of ALT activity measurement. There was also reported the optimal conditions to create this biosensor (including enzyme immobilization parameters and substrates concentrations). The analytical characteristics were investigated including the sensitivity, the linear range, the minimum limit of detection, time of measurement, duration of analysis, stability, etc. Also, there was explored the biosensor selectivity to different interferents, e.g., electroactive molecules and amino acids. For the purpose to test the fundamental possibility of this biosensor to measure the ALT activity in real samples, the operation of the biosensor was tested in a solution with an ionic composition close to serum. [ABSTRACT FROM AUTHOR]

Developing new flexible and electroactive materials is a significant challenge to producing safe, reliable, and environmentally friendly energy storage devices. This study introduces a promising electrolyte system that fulfills these requirements. First, polypyrrole (PPy) nanotubes are electropolymerized in graphite‐thread electrodes using methyl orange (MO) templates in an acidic medium. The modification increases the conductivity and does not compromise the flexibility of the electrodes. Next, flexible supercapacitors are built using hydrogel prepared from poly(vinyl alcohol) (PVA)/sodium alginate (SA) obtained by freeze–thawing and swollen with ionic solutions as an electrolyte. The material exhibits a homogenous and porous hydrogel matrix allowing a high conductivity of 3.6 mS cm−1 as‐prepared while displaying great versatility, changing its electrochemical and mechanical properties depending on the swollen electrolyte. Therefore, it allows its combination with modified graphite‐thread electrodes into a quasi‐solid electrochemical energy storage device, achieving a specific capacitance (Cs) value of 66 F g−1 at 0.5 A g−1. Finally, the flexible device exhibits specific energy and power values of 19.9 W kg−1 and 3.0 Wh kg−1, relying on the liquid phase in the hydrogel matrix produced from biodegradable polymers. This study shows an environment friendly, flexible, and tunable quasi‐solid electrolyte, depending on a simple swell experiment to shape its properties according to its application. [ABSTRACT FROM AUTHOR]

In this study, we evaluated the state of water by performing infrared (IR) spectroscopic analysis in the 4000–100 cm−1 region. The effects of ions on the structure of water molecules were investigated by analyzing specific IR bands of salt solutions in the 1000–100 cm−1 region. Chloride solutions of Li, Na, K, Cs, Ba, and Ca were prepared at different concentrations, and their IR spectra were recorded by the attenuated total reflection method. The isosbestic point was observed in the 1000–100 cm−1 region, and the position was related to the ratio of the Stokes radius and effective ionic radius of each ion. Two bands were identified at around 660 and 400 cm−1 by curve fitting, and the intensity ratio increased linearly with a decrease in water activity. Thus, this demonstrates the potential of the 1000–100 cm−1 region as a marker for the evaluation of water structure subjected to ions. Moreover, it is possible to evaluate different states of water simultaneously by combining this with the band in the 4000–3000 cm−1 region. These results successfully demonstrate the effectiveness of the spectra in the 1000–100 cm−1 region to evaluate the state of water in ionic solutions. Graphical Abstract This is a visual representation of the abstract. [ABSTRACT FROM AUTHOR]

We report development and preparation of synthetic polypeptide based, coacervate core polyelectrolyte complex micelles, PCMs, in aqueous media, which were characterized and evaluated for the encapsulation and in vitro release of a model single-stranded RNA, polyadenylic acid, poly(A). Cationic, α-helical polypeptides pegylated at their N-termini, PEG113-b-5bn and PEG113-b-5cn, were designed to form coacervate core PCMs upon mixing with multivalent anions in aqueous media. Sodium tripolyphosphate (TPP) and poly(A) were used as model multivalent anions that allowed optimization of polypeptide composition and chain length for formation of stable, nanoscale PCMs. PEG113-b-5c27 was selected for preparation of PCMs that were characterized under different environmental conditions using dynamic light scattering, atomic force microscopy and cryoelectron microscopy. The PCMs were found to efficiently encapsulate poly(A), were stable at physiologically relevant pH and solution ionic strength, and were able to release poly(A) in the presence of excess polyvalent anions. These PCMs were found to be a promising model system for further development of polypeptide based therapeutic delivery vehicles. [ABSTRACT FROM AUTHOR]

Demineralization is essential in various fields, from ocean acidification to orthopaedics. Currently, demineralization is generally ascribed to etching by corrosive acids. Herein, the "supervariate" strategy for the demineralization of calcite (the most abundant biomineral on Earth, and a major component of Earth's crust) is disclosed, in which nontoxic solutions of multiple ionic species are used to convert calcite into a multi‐ionic amorphous gel that exhibits moderate flowability, which means it can be conveniently collected, stored, transferred, and moulded. This transformation is enabled by the facile formation of highly stable "supervariate" gels featuring high entropy (as a result of their disordered structure, containing various ionic and hydration species) and high resistance to crystallization. Overall, a novel, safe, generic method for etching, gelatinating, and processing solid ceramics is described. [ABSTRACT FROM AUTHOR]

In this paper, acrylamide (AM), cellulose nanocrystals (CNCs), and reduced graphene oxide (rGO) were used as raw materials to prepare PAM/CNC/rGO interpenetrating network composite hydrogels by in situ free radical polymerization. Ions were introduced by soaking the composite hydrogels in an ionic solution. The composite hydrogels were characterized using scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) and tested for their mechanical, electrical, sensing, and water-retention properties. When 0.15 g of rGO was added, the composite hydrogel exhibited a large elongation at break (up to 680%) and tensile strength (0.28 MPa). The composite hydrogel has a high sensitivity factor (11.79) in the strain range of 300–400%, showing excellent strain sensitivity. After being immersed in 0.3 mol L−1 calcium chloride solution for 3 h, the conductivity of the composite hydrogel reached 3.39 S m−1, showing good conductivity. Therefore, the PAM/CNC/rGO interpenetrating network composite hydrogel has potential application value in the field of flexible sensors. [ABSTRACT FROM AUTHOR]

Introduction: Oxyntomodulin (Oxm) hormone peptide has a number of beneficial effects on nutrition and metabolism including increased energy expenditure and reduced body weight gain. Despite its many advantages as a potential therapeutic agent, Oxm is subjected to rapid renal clearance and protease degradation limiting its clinical application. Previously, we have shown that subcutaneous administration of a fibrillar Oxm formulation can significantly prolong its bioactivity in vivo from a few hours to a few days. Methods: We used a protease resistant analogue of Oxm, Aib2-Oxm, to form nanfibrils depot and improve serum stability of released peptide. The nanofibrils and monomeric peptide in solution were characterized by spectroscopic, microscopic techniques, potency assay, QCM-D and in vivo studies. Results: We show that in comparison to Oxm, Aib2-Oxm fibrils display a slower elongation rate requiring higher ionic strength solutions, and a higher propensity to dissociate. Upon subcutaneous administration of fibrillar Aib2-Oxm in rodents, a 5-fold increase in bioactivity relative to fibrillar Oxm and a significantly longer bioactivity than free Aib2-Oxm were characterized. Importantly, a decrease in food intake was observed up to 72-hour post-administration, which was not seen for free Aib2-Oxm. Conclusion: Our findings provides compelling evidence for the development of long-lasting peptide fibrillar formulations that yield extended plasma exposure and enhanced in vivo pharmacological response. [ABSTRACT FROM AUTHOR]

Experiments quantifying GCL permittivity and the ultimate water head the GCLs can sustain before the initiation of internal erosion when underlain by a 50 mm angular to subangular gravel subgrade are conducted. The influence of different geotextiles over the subgrade, water heads, hydration periods before testing, masses per unit area of bentonite within the GCL, and ionic strengths of the solution (cation exchange) are considered. Test results show that GCL with the scrim-reinforced nonwoven geotextile over the subgrade has the best hydraulic performance against internal erosion, followed by the woven geotextile coated with a 110 g/m2 polypropylene film. A woven or nonwoven is the least useful for preventing internal erosion, with the corresponding threshold water head initiating internal erosion >39 m for scrim-reinforced nonwoven, 21 m for lightly coated woven, 4–5 m for woven and nonwoven alone, respectively. Cation exchange, length of hydration, and mass per unit area of bentonite do not notably affect the threshold water head for the subgrade examined. Once internal erosion occurs, there is a 3-order of magnitude increase in permittivity. The practical implications are discussed. • First large-scale test evaluating the effect of carrier geotextile on GCL against internal erosion. • First guidance on the threshold water head above four commonly used GCL products initiating internal erosion. • Evaluation of the effect of hydration period, mass per unit area of bentonite, and cation exchange on GCL against erosion. [ABSTRACT FROM AUTHOR]

The preservative qualities of individual ionic compounds impacting the infectivity of T4 virions were elucidated. T4 virions were immersed in quasi-pure ionic solutions prior to the adsorption process, and the plaque forming unit (pfu) values of these were measured following the conventional method. In neutral ionic solutions, the minimum and the optimum concentrations of preservative qualities corresponded with the results obtained from the multi-ionic media/buffers. In acid and alkali solutions, phages show tolerances at a pH range of 5–11 in multi-ionic media/buffers. T4 virions show no tolerance in quasi-pure acid, neutral, and weak alkaline conditions. The preservative quality of T4 virions increased in over 10−1 mM OH− solution, equivalent to a pH value over 10, which corresponds to the pKa of the deprotonation of the DNA bases G and T. Infectivity was lost below 10−1 mM OH− and higher than 10 mM OH−. These results imply that maintaining infectivity of a virion may need the flexibility of the intra-capsid DNA by deprotonation. [ABSTRACT FROM AUTHOR]

We have recently described the fate of gamma-alumina-based nanomaterials containing Ni and non-nanometric Ni on soil from lysimeters. The objectives of the present work were to evaluate the effects of Al and Ni from nanomaterials, aluminas and non-nanometric Ni on seedlings elongation and on tomato plants growth; the quantification of Al and Ni incorporation in seedlings, by neutron activation and a preliminary analysis of nutrient elements present in stems and leaves of plants, by scanning electron microscopy. Non-nanometric Ni inhibited root and hypocotyl elongation in a concentration-dependent manner, while acid alumina and two nanomaterials caused greater elongation of seedlings. Ni and Al incorporation was demonstrated, except for one nanomaterial. In experiments with plants, they were grown in garden soil alone and mixtures also containing soil from Gan Gan, Chubut province, Argentina. The fresh and dry weight of plants aerial parts were significantly lower under treatments in different soil mixtures with Ni(NO3)2.6H2O (190 mg/L) compared to the Control plants (0.33 ± 0.02 vs 0.49 ± 0.10 and 0.005 ± 0.0001 vs 0.007 ± 0.003 g/plant respectively). It was demonstrated that non-nanometric Ni was toxic to the plants. More trials should be carried out to elucidate whether nanomaterials can be related to alterations on nutrient elements and be toxic to tomato plants. [ABSTRACT FROM AUTHOR]

The results of an experimental study and simulation of radiation generated by the processes of collisional-radiative recombination of neon ions Ne+ and Ne++ with electrons of the decaying plasma are presented. Plasma was created by a barrier discharge in a cylindrical glass tube with electrodes on its surface. Experimental conditions: neon pressure 0.65Torr, electron density at the initial stage of the afterglow [e] ~ (1–5) × 1011 cm–3. The main attention is paid to the comparative analysis of the collisional-radiative recombination of Ne+ and Ne++ ions based on the numerical solution of coupled differential equations for the densities of charged and long-lived excited particles and the electron temperature, taking into account the main elementary processes in decaying neon plasma. Comparison of the model solutions with the intensities of ionic and atomic spectral lines measured by the multichannel photon counting method indicates the need to refine the dependence of the rate of collisional-radiative recombination on the ion charge. [ABSTRACT FROM AUTHOR]

The recovery of gold from water is an important research area. Recent reports have highlighted the ultrahigh capacity and selective extraction of gold from electronic waste using reduced graphene oxide (rGO). Here, we made a further attempt with the thermal rGO membranes and found that the thermal rGO membranes also had a similarly high adsorption efficiency (1.79 g gold per gram of rGO membranes at 1000 ppm). Furthermore, we paid special attention to the detailed selectivity between Au3+ and other ions by rGO membranes. The maximum adsorption capacity for Au3+ ions was about 16 times that of Cu2+ ions and 10 times that of Fe3+ ions in a mixture solution with equal proportions of Au3+/Cu2+ and Au3+/Fe3+. In a mixed-ion solution containing Au3+:Cu2+:Na+:Fe3+:Mg2+ of printed circuit board (PCB), the mass of Au3+:Cu2+:Na+:Fe3+:Mg2+ in rGO membranes is four orders of magnitude higher than the initial mass ratio. A theoretical analysis indicates that this selectivity may be attributed to the difference in the adsorption energy between the metal ions and the rGO membrane. The results are conducive to the usage of rGO membranes as adsorbents for Au capture from secondary metal resources in the industrial sector. [ABSTRACT FROM AUTHOR]

The hydrolysis reactions of crystal violet (CV) and p‐nitrophenyl acetate (PNPA) by sodium hydroxide in cetyltrimethylammonium bromide (CTAB) micellar solution were studied in this work. Combined with the Boltzmann probability of ionic species in an electrostatic potential field, a model with a numerical scheme was developed based on the nonlinear Poisson−Boltzmann equation in the micelle‐cell consisting of the reactants and the surfactant. The numerical solution gives the ionic species distribution in the micelle phase and the radius of the micelle‐phase. The dielectric constant of the micelle‐phase varies in the range of 39.8−54.4. The second‐order reaction rate constants in the micelle‐phase were determined using the electrostatic and dipolar free energy models. For the basic hydrolysis of CV and PNPA, the overall second‐order rate constants are three to five times and 1.4 times greater than the corresponding values in water, respectively. The rate enhancement occurs due to the distribution of the reactive ionic species in the cell region and the enhancement of the Coulombic and dipolar interactions among the ionic and polar reactants. [ABSTRACT FROM AUTHOR]

In the current era that it is strongly expected the SDGs would be achieved, electrolyte solutions in electrochemical devices and processes are being studied from dilute and concentrated solutions, through inorganic molten salts, deep eutectic solvents, and ionic liquids, to super‐concentrated solutions. Although concepts based on empirical laws such as the Walden rule and hydrodynamics such as the Stokes rule are still useful for ionic conduction in solution, it is expected that superionic conduction‐like mechanisms that are scarcely found in conventional electrolytes. Here, the authors′ recent results are described based on the local structure and speciation of ionic species in solution, focusing on protons and lithium ions. [ABSTRACT FROM AUTHOR]

Polyphenol oxidases (PPO) are enzymes that catalyze the browning of fruits and vegetables when oxygen in the air reacts with the present phenolic compounds. This study demonstrates the enzymatic browning of food samples and the inhibition of its activity by common household materials. Fresh food samples were tested in different treatments of acidic and ionic solutions, and syrups. Observations from the students' work showed that changes in pH, surface area for the site of reaction, and ionic conditions affect enzymatic browning. The deviation from the optimum working pH, introduction of ionic interaction, and alteration of the surface area led to the interruption of the interaction within the enzyme structure and between its active site and the substrate thereby inhibiting the enzyme function. Results of the experiment can also serve as a basis for further studies on the development of methods and products to inhibit PPO action and maintain the sensory value and nutritional quality of foods. Furthermore, experiments of similar nature can be crafted as practical activities and alternative teaching techniques designed for students to apply chemistry concepts and laboratory fundamentals to the conduct of an experiment suited for the flexible learning set-up. [ABSTRACT FROM AUTHOR]