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Crude oil and petroleum products contain various types of sulfur compounds: aliphatic and aromatic mercaptans, hydrogen sulfide, sulfides, disulfides, thiophene derivatives, etc. Some of these may dissolve in water only slightly, but their toxicity and corrosiveness indicate that even these small amounts should be eliminated from water. This work examines, for the first time, the removal of thiophenol (synonyms: benzenethiol, phenyl mercaptan) from water using sepiolite. This clay mineral (evaluated by SEM analysis) is an attractive natural sorbent characterized by its microporosity, which results from its crystalline structure and large specific surface area. Because the structure of thiophenol changes depending on the pH of the aqueous solution (due to the loss of a proton), the research was conducted at pH 4, 7 and 9. The detection of thiophenol in aqueous solution was investigated using UV spectroscopy. It was found that the adsorption of thiophenol is possible, but it occurs only in an acidic environment (pH 4). No sorption is observed at pH 7 or 9. The adsorption of thiophenol at pH 4 does not change significantly after changing the ionic strength of the aqueous solution (distilled water, 0.01 NaCl and 0.1 NaCl). The adsorption capacity of sepioliteis approximately 0.23–0.34 mg/g. Studies using infrared spectroscopy and fitting of Freundlich and Langmuir isotherm models to the results of adsorption experiments indicate that adsorption on unmodified sepiolite follows a physisorption mechanism. Additionally, to understand the behavior of thiophenol in the presence of sepiolite across different pH ranges, DFT/PCM/B3LYP/Aug-CC-pVDZ calculations were used to analyze the charge distribution on particular atoms in its structure. [ABSTRACT FROM AUTHOR]

Recent studies show that biofilm substances in contact with nanoplastics play an important role in the aggregation and sedimentation of nanoplastics. Consequences of these processes are changes in biofilm formation and stability and changes in the transport and fate of pollutants in the environment. Having a deeper understanding of the nanoplastics–biofilm interaction would help to evaluate the risks posed by uncontrolled nanoplastic pollution. These interactions are impacted by environmental changes due to climate change, such as, e.g., the acidification of surface waters. We apply fluorescence correlation spectroscopy (FCS) to investigate the pH-dependent aggregation tendency of non-functionalized polystyrene (PS) nanoparticles (NPs) due to intermolecular forces with model extracellular biofilm substances. Our biofilm model consists of bovine serum albumin (BSA), which serves as a representative for globular proteins, and the polysaccharide alginate, which is a main component in many biofilms, in solutions containing Na+ with an ionic strength being realistic for fresh-water conditions. Biomolecule concentrations ranging from 0.5 g/L up to at maximum 21 g/L are considered. We use non-functionalized PS NPs as representative for mostly negatively charged nanoplastics. BSA promotes NP aggregation through adsorption onto the NPs and BSA-mediated bridging. In BSA–alginate mixtures, the alginate hampers this interaction, most likely due to alginate–BSA complex formation. In most BSA–alginate mixtures as in alginate alone, NP aggregation is predominantly driven by weaker, pH-independent depletion forces. The stabilizing effect of alginate is only weakened at high BSA contents, when the electrostatic BSA–BSA attraction is not sufficiently screened by the alginate. This study clearly shows that it is crucial to consider correlative effects between multiple biofilm components to better understand the NP aggregation in the presence of complex biofilm substances. Single-component biofilm model systems based on comparing the total organic carbon (TOC) content of the extracellular biofilm substances, as usually considered, would have led to a misjudgment of the stability towards aggregation. [ABSTRACT FROM AUTHOR]

The tunability of the lower critical solution temperature (LCST) of poly(N‐isopropylacrylamide) (PNIPAM) to lower or higher temperatures, as well as the ease of modulation of the LCST phase transition kinetics broadens the scope of application of PNIPAM‐based materials in biomedical fields. This work reports a facile approach to formulate a smart, injectable cellulose nanofibril (CNF)/PNIPAM hybrid gel. Hofmeister salts are used to induce ion‐mediated gelation of the nanofibrils and PNIPAM chains, resulting in an interpenetrating network (IPN) structure. From rheological measurements, the hybrid material displays excellent structural integrity at room temperature and tunable thermo‐stiffening around body temperature. De‐swelling kinetics can be modulated by varying the nature and concentration of the Hofmeister ion used. The successful realization of the IPN hybrid gel structure is dependent on the molecular weight of PNIPAM used. Moreover, the hybrid gels show good thermo‐reversibility during thermal cycling, as well as excellent injectability and remarkable self‐healing post‐injection, owing to shear‐thinning and thixotropic characters. Since rheology is a crucial technique in the analysis of soft matter and flow behavior is fundamental for the design and synthesis of application‐specific viscoelastic materials, the work reported herein provides a rheological basis for careful design and synthesis of smart gels. [ABSTRACT FROM AUTHOR]

The loss of soluble cationic species by adsorption to glass vial walls is problematic for experiments performed at tracer concentrations. Silanization increases glass hydrophobicity to reduce cation sorption to glass surfaces. This work examines the efficacy of silanization in decreasing europium and thorium loss through glass sorption in aqueous and mixed aqueous/organic phases. The influence of the solution pH, ionic strength, electrolyte, metal concentration, organic diluent's nature, and the addition of complexing extractants was investigated. Overall, results indicate that silanization effectively decreases cation loss to sorption to glass walls. [ABSTRACT FROM AUTHOR]

The development of environmentally friendly, operationally simple, and easily separable adsorbents for uranium removal from wastewater holds significant importance. The biopolymer gelatin (Gel) derived from animal collagen has poor water stability, limiting its application in wastewater treatment. By in-situ compositing with ZIF-67, a nitrogen-rich and stable metal–organic framework structure introduced onto the surface of gelatin fibers enhanced the uranium adsorption capacity of gelatin nanofibers and improved the water stability of these fibers. Furthermore, through the natural polyphenolic tannic acid tanning process, it is possible to further increase selectivity of gelatin composite fibers. The gelatin composite nanofibers Gel/ZIF-67 and T-Gel/ZIF-67 were characterized using SEM, FT-IR, XRD, XPS, and contact angle. Adsorption of uranium on both nanofibers were significantly influenced by pH but minimally affected by ionic strength, indicating the inner-sphere surface complexation. The adsorption of uranium onto Gel/ZIF-67 and T-Gel/ZIF-67 followed the Langmuir isotherm model, with theoretical adsorption capacities reaching up to 608.21 mg g−1 and 612.24 mg g−1, respectively. Kinetic modeling analysis revealed that chemical adsorption played a dominant role during the adsorption processes. [ABSTRACT FROM AUTHOR]

This research investigates the interactions between Carbopol® and zinc microparticles and their role in the stabilization of zinc within the framework of zinc slurry–air redox flow batteries (Zn-air RFBs). The study explores the potential of yield stress fluids, particularly PAA (Carbopol®) microgels, as stabilizers for zinc particles during battery operation, and regarding sedimentation in particular. Two effects that can limit the effectiveness of PAA yield stress in stabilizing the suspension are examined in this study. First is the ionic strength and pH that can evolve during the slurry formulation. The second effect is associated to zinc polymer interactions that can develop during the suspension preparation. Using methodologies based on rheometry and UV–Vis spectroscopy, the research identifies that the primary stabilization challenge is the adsorption of Carbopol® microgels onto zinc surfaces, which significantly influences the gel's yield stress. These insights contribute to an enhanced understanding of the physical chemistry of the suspending fluid, facilitating the development of more efficient and stable Zn-Air RFBs. [ABSTRACT FROM AUTHOR]

The increasing interest in plant-based diets due to health concerns, sustainability, and allergenicity of animal proteins has led to a surge in the use of plant proteins. However, their low functionality has made it challenging to use them in developing drugs and digesting new foods. The Maillard reaction which occurs naturally between proteins and polysaccharides presents a potential solution to this problem. However, its sensitivity to temperature, pH levels, and ionic strength makes its use in the food and pharmaceutical sectors problematic. This review explores different Maillard conjugation strategies using plant proteins and polysaccharides to provide a better understanding of their potential for generating protein functions in the food industry. The review highlights the importance of this technique in creating new and functional food products that are safe and sustainable. [ABSTRACT FROM AUTHOR]

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A kinetic-spectrophotometric method has been devised to analyze the oxidation reaction of Para-aminobenzyl alcohol [PABAlc] catalyzed by Ag (I). PABAlc is used in numerous fields of pharmaceutical and medicinal chemistry as intermediates. The harmful effects of PABAlc cannot be overlooked in spite of its manifold applications. The toxicity of PABAlc may lead to allergic reactions, serious eye damage, respiratory tract infections amongst few. It became utmost important to formulate a method to establish the presence of PABAlc in a particular sample of water in order to circumvent its proximity to common people. In our work, we have provided an insight to an oxidation process using PABAlc as substrate catalyzed by Ag (I) ions besides proposing a reaction mechanism of the reaction under study with substantial data in the form of different thermodynamic parameters like activation energy (55 kJ/mol−1), temperature coefficient (1.92), enthalpy of activation (52.89 kJ/mol−1), alongside deets related to various effects of oxidant, substrate, catalyst, temperature, pH, ionic strength, and so on, on reaction kinetics. Additionally, the product formed in the proposed mechanism has its commercial importance in the field of pharmacy, dyes, and so on, sufficient enough to put forward a rationale for the investigations. [ABSTRACT FROM AUTHOR]

In this study, the efficacy of sono-assisted adsorption for the removal of methyl violet 2B (MV-2B) was investigated. A magnetic adsorbent was synthesized using kaolin and TiO2, designated as KTF. Various analyses including scanning electron microscopy with energy dispersive spectroscopy (SEM–EDS), Brunauer–Emmett–Teller (BET), Fourier transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRD), Zeta potential and vibrating sample magnetometer (VSM) were conducted to characterize the structure of KTF. The BET surface area and pore volume of KTF were determined to be 65.279 m2/g and 0.072 cm3/g, respectively. VSM analysis confirmed the superparamagnetic property of KTF. The effect of contact time, initial MV-2B concentration, KTF amount, temperature, ionic strength and initial pH of the solution on the sono-assisted adsorption of MV-2B was investigated. Sono-assisted removal of MV-2B was achieved at a rate of 85.6% under optimal conditions: original pH, KTF amount of 0.2 g/100 mL, initial MV-2B concentration of 20 mg/L, contact time of 15 min, and temperature of 22 °C. Conversely, lower removal efficiencies were observed with conventional adsorption methods employing shaking (37%) and stirring (60.5%). The kinetics of sono-assisted MV-2B removal followed a pseudo-second order model, while the Freundlich isotherm model exhibited a superior fit (R2 = 0.985) in describing the equilibrium behavior compared to Langmuir and Temkin models. [ABSTRACT FROM AUTHOR]

A conceptual mathematical model was developed to describe the migration of aggregating nanoparticles in water saturated, homogeneous porous media with one‐dimensional uniform flow. Nanoparticles can be found suspended in the aqueous phase or attached reversibly and/or irreversibly onto the solid matrix. The Smoluchowski population balance equation (PBE) was used to model the process of particle aggregation and was coupled with the advection‐dispersion‐attachment equation to form a nonlinear transport model. Furthermore, an efficient and accurate solver for the PBE, and an iterative solver for the linear or nonlinear attachment equations were employed. The new numerical model was applied to nanoparticle transport experimental data available in the literature. Although, conventional transport models can be used to describe nanoparticle migration at low ionic strength conditions, such models might not be applicable for high ionic strength conditions, where aggregation becomes a dominant process. Aggregation is significantly affecting the transport characteristics of nanoparticles. Under high ionic strength conditions, the mass retention in the solid matrix of the porous medium increases, and a nonlinear particle attachment behavior may be observed. The proposed model performed remarkably well, successfully capturing numerous physical processes associated with nanoparticle transport, including particle‐size‐dependent dispersion. Ignoring the aggregation process and using conventional colloidal transport models to model nanoparticle transport may lead to erroneous results. [ABSTRACT FROM AUTHOR]

In recent years, graphene biosensors have received much attention due to their high sensitivity, low noise and low detection limit. Vertical graphene field effect transistors (VGFETs) based on graphene/semiconductor heterojunctions are characterized by high switching ratios and have wide application prospects. In this study, we prepared the ion-gel gate VGFETs and used them for bovine serum albumin (BSA) quantification sensors. The results showed that the adsorption of BSA molecules on the substrate surface was maximized when the ionic strength was 10−3M. The limit of detection (LOD) of BSA concentration was 1μg/ml, suitable for simple and rapid quantitative analysis of protein molecules. [ABSTRACT FROM AUTHOR]

Background: Understanding the release characteristics of soil colloids is a prerequisite for studying the co-transport of colloids and pollutants in subsurface environment. As a crucial agricultural management measure, fertilization not only alters the material composition of farmland soil, but also significantly regulates the properties and release patterns of soil colloids. This study systematically investigated the regulatory mechanism of short-term cattle manure fertilization on the macroscopic release and microscopic properties of soil colloids with different particle sizes, providing a theoretical foundation for subsequent research on the fate and transport of agricultural non-point source pollutants. Results: The colloids in natural agricultural soil primarily consist of inorganic components. Graded extraction of the colloids has revealed that the combined proportion of colloids with particle sizes of 1–2 μm and 0.45–1 μm accounts for approximately 80.5%. Applying cattle manure inhibits the release of soil colloids, and the content of large particle size (1–2 μm) components increases. The content of organic colloids is increased due to the high total organic carbon (TOC) in cattle manure, particularly those with a particle size less than 1 μm. The characterization of organic colloid components revealed a significant increase in aromatic carbon and oxygen-containing functional groups, while the aliphatic content decreased. The response sequence regarding changes in functional groups within organic colloids induced by fertilization was as follows: –CH3, –CH2 > C–O > –OH > C=C. Fertilization promotes the release of 1:1-type inorganic mineral colloids, increasing the content of poorly crystalline minerals. The retention of aromatic carbon and oxygen-containing functional groups by poorly crystalline mineral colloids served as the primary mechanism leading to their increased content levels. Changes in environmental factors significantly impacted the release and properties of soil colloids. Conditions such as low cationic valence, high ionic strength, and high pH promoted the release of soil colloids. Conclusions: The short-term fertilization resulted in a reduction in the release of soil colloids and brought about significant alterations in their particle size composition and properties. The findings of this study provide valuable insights into understanding the impact of fertilization-induced colloid release on the environmental behavior of agricultural non-point source pollutants. [ABSTRACT FROM AUTHOR]

Granular activated carbon has been modified by ammonium persulfate as a new adsorbent for Cr(VI) adsorption from aqueous solutions. The adsorbent was characterized by nitrogen adsorption–desorption isotherm data and infrared spectroscopy. The impact of different factors, such as the initial pH level of the solution, time, temperature, ionic strength, and initial concentration of the Cr(VI) ion, on the adsorption efficiencies of the adsorbent has been studied by batch experiments. Kinetic studies and the adsorption thermodynamics of Cr(VI) with ammonium persulfate-modified activated carbon adsorbent were carefully studied. The results showed that the Cr(VI) adsorption follows a pseudo-second-order kinetic model and the adsorption reaction is endothermic and spontaneous. The adsorption isotherm was scrutinized, and the fitting results showed that the Langmuir model could well represent the adsorption process. The maximum adsorption capacity of Cr(VI) onto persulfate-modified activated carbon was 108.69 mg g−1. The research results showed that using persulfate-modified activated carbon adsorbent can greatly remove Cr(VI) from aqueous solutions. [ABSTRACT FROM AUTHOR]

In recent years, European Union member states have hastened energy policy deliberations to address supply and sustainability concerns, placing a significant emphasis on nuclear energy as a means to achieve decarbonization goals. However, despite its significant role in power generation, nuclear energy faces significant challenges linked to fuel reprocessing and waste disposal, that hinder its broader expansion. In this context, the separation of technetium represents a concerning issue. Indeed, technetium's catalytic activity can impede the extraction of uranium, neptunium, and plutonium, affecting waste reprocessing efficiency. Additionally, the stable form of technetium in aerobic conditions, pertechnetate (TcO4−), poses risks of groundwater contamination due to its mobility and solubility. Hence, sensing and separation of TcO4− is imperative for both nuclear fuel processing and minimising radioactive contamination in the environment. However, the binding of TcO4− and its separation from contaminated solutions present challenges due to the acidic (or basic) waste components and the high ionic strength in real matrices. Supramolecular chemists have addressed these issues by designing receptors inspired by molecular recognition principles. This article explores recent advancements and future directions in TcO4− sensing and separation (using extraction and sorption) with a focus on molecular hosts. Metal‐organic receptors will also be discussed. [ABSTRACT FROM AUTHOR]

Stimuli‐responsive shape‐morphing hydrogels with self‐healing and tunable physiochemical properties are excellent candidates for functional building blocks of untethered small‐scale soft robots. With mechanical properties similar to soft organs and tissues, such robots enable minimally invasive medical procedures, such as cargo/cell transportation. In this work, responsive hydrogels based on zwitterionic/acrylate chemistry with self‐healing and stimuli‐responsiveness are synthesized. Such hydrogels are then judiciously cut and pasted to form hybrid constructs with predetermined swelling and elastic anisotropy. This method is used to program hydrogel constructs with predetermined 2D‐to‐3D deformation upon exposure to different environmental ionic strengths. Untethered soft robotic functionalities are demonstrated, such as actuation, magnetic locomotion, and targeted transport of soft and light cargo in flooded media. The proposed hydrogel expands the repertoire of functional materials for fabricating small‐scale soft robots. [ABSTRACT FROM AUTHOR]

In recent years, European Union member states have hastened energy policy deliberations to address supply and sustainability concerns, placing a significant emphasis on nuclear energy as a means to achieve decarbonization goals. However, despite its significant role in power generation, nuclear energy faces significant challenges linked to fuel reprocessing and waste disposal, that hinder its broader expansion. In this context, the separation of technetium represents a concerning issue. Indeed, technetium's catalytic activity can impede the extraction of uranium, neptunium, and plutonium, affecting waste reprocessing efficiency. Additionally, the stable form of technetium in aerobic conditions, pertechnetate (TcO4−), poses risks of groundwater contamination due to its mobility and solubility. Hence, sensing and separation of TcO4− is imperative for both nuclear fuel processing and minimising radioactive contamination in the environment. However, the binding of TcO4− and its separation from contaminated solutions present challenges due to the acidic (or basic) waste components and the high ionic strength in real matrices. Supramolecular chemists have addressed these issues by designing receptors inspired by molecular recognition principles. This article explores recent advancements and future directions in TcO4− sensing and separation (using extraction and sorption) with a focus on molecular hosts. Metal‐organic receptors will also be discussed. [ABSTRACT FROM AUTHOR]

In this study, magnetic coconut shell biochar loaded with spherical Fe3O4 and γ-Fe2O3 particles was successfully synthesized using a chemical coprecipitation method. The magnetic biochar exhibited a good magnetic separability and environmental security. The maximum sulfadiazine (SDZ) and norfloxacin (NOR) removal efficiencies were 94.8% and 92.3% at pH 4 and 25 °C with adsorbent dosage of 2.5 g/L, respectively. When antibiotic concentrations ranged from 5 to 50 mg/L, the theoretical maximum adsorption capacities of SDZ and NOR were 16.7 mg/g and 25.8 mg/g, respectively. The Langmuir isotherm and pseudo-second-order kinetic models could better describe the adsorption process of both antibiotics, implying the monolayer chemical adsorption. The thermodynamic analysis indicated that the adsorption process was spontaneous and endothermic. The ionic strength had no significant effect on the adsorption behavior of either antibiotic. Combined with BET, FTIR, and XPS results, the dominant mechanisms for SDZ and NOR adsorption were pore filling, π-π electron-donor–acceptor interaction, hydrogen bonds and surface complexation. Moreover, Lewis acid–base interaction also contributed to SDZ adsorption. [ABSTRACT FROM AUTHOR]

The distribution coefficient (Kd) of radionuclides is a crucial parameter in assessing the safety of high-level radioactive waste (HLW) geological repository. It is determined in the laboratory through batch and column experiments. However, differences in obtained Kd values from distinct experiments have not been thoroughly assessed and compared. This study evaluated strontium (Sr) sorption on different granite materials using static batch and dynamic experiments (column and core-flooding experiments). The results from batch sorption experiments showed higher Sr sorption on granite under acidic and strongly alkaline conditions, low solid–liquid ratios, and low ionic strength. In column experiments, a two-site sorption model was used to simulate Sr transport in crushed granite and mixed pure minerals. The sorption of Sr on crushed granite exhibited a higher affinity than that of mixed pure minerals. The dual-porosity transport model was employed to investigate Sr transport behavior in fractured granite in the core-flooding experiment. Kd obtained from batch sorption experiments are four to twenty times higher than those from column experiments, and two to three orders of magnitude higher than that from a core-flooding experiment. The results of this study provide valuable insights into safety assessment for the HLW geological repository. [ABSTRACT FROM AUTHOR]

The organic xerogel (OX) was synthesized through sol–gel polymerization of formaldehyde and resorcinol in inverse emulsion using Na2CO3 as a catalyst. Meanwhile, OX containing sepiolite (OX-Sep) and vermiculite (OX-Ver) were prepared similarly to OX but adding clays during synthesis. All materials were mesoporous and presented spherical morphology, and the surface of these materials exhibited an acidic character because the concentration of acidic sites was higher than those of basic sites. Cd(II) adsorption from aqueous solutions onto OX, OX-Sep, and OX-Ver was examined, and the OX-Sep showed the highest adsorption capacity towards Cd(II) of 189.7 mg/g, being 1.5, 2, and 36 times higher than that of OX-Ver, OX, and Sep. The OX-Sep capacity for adsorbing Cd(II) was significantly lessened by decreasing the pH from 7 to 4 and raising the ionic strength from 0.01 N to 0.1 N. This trend was ascribed to electrostatic attraction between the Cd+2 in water and the negatively charged surface of OX-Sep. Besides, desorption studies at pH 4 showed that the average desorption percentage of Cd(II) adsorbed on OX-Sep was 80%. The characterization results and the effect of the operating conditions on the adsorption capacity proved that electrostatic attraction and cation exchange play a crucial role in the adsorption mechanism. [ABSTRACT FROM AUTHOR]

Droplet‐based microfluidics‐assisted fabrication of alginate microgels has extensive applications in biomaterials, biomedicines, and related fields. This approach is typically achieved by crosslinking droplets of an aqueous solution of sodium alginate with various divalent and trivalent ions, such as Ca2+, Ba2+, Sr2+, etc. Despite the exceptional features exhibited by bulk alginate hydrogels when using iron ions as the crosslinking reagent, including stimulus responsiveness and complex chemistry, no attention has been given to studying the fabrication of Fe‐alginate microgels through droplet microfluidics. In this work, a facile method is presented for fabricating Fe‐alginate microgels using single emulsion droplets as templates and an off‐chip crosslinking technique to solidify the droplets. The morphologies of the resulting microgels can be systematically adjusted by manipulating different parameters such as viscosities and ionic strength of the collecting solutions. It should be noted that these resulting microgels undergo a color change from light brown to dark brown due to presumed self‐oxidation of iron ions within their skeleton structure. Furthermore, these Fe‐alginate microgels are functionalized by decorating them with a positively charged linear polymer via electrostatic interactions to impart them with stable fluorescent property. These functionalized Fe‐alginate microgels may find potential applications in drug delivery carriers and biomimetic structures. [ABSTRACT FROM AUTHOR]

A novel polymer synthesized by grafting three cyclodextrins onto chitosan was characterized and evaluated for its potential to adsorb two pharmaceutical residues: ibuprofen and progesterone. The influence of various operational parameters, including contact time, initial molecule concentration, pH, ionic strength, and temperature, was investigated. The synthesized polymer exhibits an amorphous and porous structure with a remarkable swelling capacity of 9.5 mmol/g. It demonstrates remarkable adsorption capacities for progesterone and ibuprofen, reaching 90% and 75%, respectively. Kinetic studies reveal that the adsorption of both molecules follows a pseudo-second-order model. A DSC analysis elucidated the adsorption mechanism, which is governed by the formation of inclusion complexes and electrostatic interactions within the polymer network. The polymer's regeneration after 23 cycles demonstrates its sustainable adsorption efficiency. The combination of chitosan with three cyclodextrins opens up promising new avenues for water treatment and the removal of specific pollutants. This approach significantly improves the material's selectivity towards target pollutants, offering a significant advantage in pollution remediation applications. [ABSTRACT FROM AUTHOR]

The strawberry (genus Fragaria) is a plant from the rose family (Rosaceae). As the fruits are likely to be picked mechanically, they are grown close to consumption centers. The aim of this work was to develop a suitable method for detecting as many molecules as possible in order to be able to distinguish between different strawberry cultivars and geographical origins in the future. Whole strawberries of the "Albion" cultivar, grown in the Jagodica Purgerica region of Zagreb, were used. Gas chromatography-mass spectrometry (GC-MS) in SCAN mode was used to analyze the aroma profile and to determine the proportion of individual components. The samples were prepared and analyzed using the solid-phase microextraction method (SPME). The impact of SPME fiber selection and GC column type was investigated, as well as sample weight, ionic strength, agitation temperature, and sampling time. A higher ionic strength was achieved by adding a 20% NaCl solution to the sample. The aroma profile of the studied strawberry cultivar consisted of furanone, esters, aldehydes, and carboxylic acids. Optimal results were achieved by adjusting the ionic strength during 15 min of extraction and incubation. The individual compounds were identified using NIST, Wiley libraries, and the "area normalization" method. [ABSTRACT FROM AUTHOR]

Human serum albumin (HSA) corona formation on polymer microparticles of a spheroidal shape was studied using dynamic light scattering and Laser Doppler Velocimetry (LDV). Physicochemical characteristics of the albumin comprising the zeta potential and the isoelectric point were determined as a function of pH for various ionic strengths. Analogous characteristics of the polymer particles were analyzed. The adsorption of albumin on the particles was in situ monitored by LDV. The stability of the HSA-functionalized particle suspensions under various pHs and their electrokinetic properties were also determined. The deposition kinetics of the particles on mica, silica and gold sensors were investigated by optical microscopy, AFM and quartz microbalance (QCM) under diffusion and flow conditions. The obtained results were interpreted in terms of the random sequential adsorption model that allowed to estimate the range of applicability of QCM for determining the deposition kinetics of viruses and bacteria at abiotic surfaces. [ABSTRACT FROM AUTHOR]

The ability of thermoresponsive polymers to respond to temperature with a reversible conformational change makes them promising 'smart' materials for solutions in medical and biotechnological applications. In this work, two such polymers and structural isomers were studied: poly(N-isopropyl acrylamide) (PNiPAm) and poly(2-isopropyl-2-oxazoline) (PiPOx). We compare the critical solution temperatures (CST) of these polymers in D2O and H2O in the presence of Hofmeister series salts, as results obtained under these different solvent conditions are often compared. D2O has a higher dipole moment and electronegativity than H2O, which could significantly alter the CST transition. We used two complementary methods to measure the CST, dynamic light scattering (DLS) and differential scanning calorimetry (DSC) and found that the CST decreased significantly in D2O compared to H2O. In the presence of highly concentrated kosmotropes, the CST of both polymers decreased in both solvents. The influence of the kosmotropic anions was smaller than the water isotope effect at low ionic strengths but considerably higher at physiological ionic strengths. However, the Hofmeister anion effect was quantitatively different in H2O than in D2O, with the largest relative differences observed for Cl−, where the CSTs in D2O decreased more than in H2O measured by DLS but less by DSC. PiPOx was more sensitive than PNiPAm to the presence of chaotropes. It exhibited much higher transition enthalpies and multistep transitions, especially in aqueous solutions. Our results highlight that measurements of thermoresponsive polymer properties in D2O cannot be compared directly or quantitatively to application conditions or even measurements performed in H2O. [ABSTRACT FROM AUTHOR]

Many food proteins can be assembled into nanofibrils under pH conditions far from the isoelectric point and with a low ionic strength by heating them for a long period. These food protein nanofibrils (FPN) have outstanding functional and biological properties and are considered sustainable biomaterials in many fields. In this study, we review the recent developments in FPN gels and introduce the key factors in promoting food protein self-assembly in order to create functional gels. The major variables discussed are the morphology of nanofibrils, protein concentration, heating time, and the type and concentration of salts. We also highlight current advances in the formation and properties of different types of FPN gels. In addition, the various applications of FPN gels in bioactive and nutrient delivery, adsorbents for CO2 and toxic pollutants, cell scaffolding biomaterials, biosensors, and others are introduced and discussed. [ABSTRACT FROM AUTHOR]

Soil-bentonite (S-B) barriers have been widely used for heavy metal pollution containment. This study conducted batch adsorption tests and diffusion-through tests to evaluate how ionic strength and bentonite ratio influence the migration of Cr(VI) in natural clay-bentonite mixtures. The test results indicated that the adsorption of Cr(VI) exhibited an obvious anion adsorption effect, the pH of the soil mixture increased with the addition of bentonite, resulting in a decrease in the positive surface charge. This change led to a decrease in Cr(VI) adsorption capacity, from 775.19 mg/kg for pure clay to 378 mg/kg for mixture samples with excessive bentonite. Furthermore, as the ionic strength increases from 0 to 0.1 M, the Cr(VI) adsorption capacity increases slightly due to the weakening of electrostatic repulsion on the clay particle surface, but the effective diffusion coefficient (De) increases by 21.97%. The compression of the diffusion double layer (DDL) under high ionic strength conditions enlarges the diffusion path and enhances the migration of Cr(VI) through the pore flow paths. Moreover, hydrated bentonite effectively fills the interaggregate pores of natural clay, thus creating narrower and more tortuous flow paths. However, excessive bentonite increases the pH value and pore volume, resulting in changes to the soil microstructure and disrupting the continuous skeleton of natural clay, which is unfavorable for Cr(VI) containment. Based on the study of the Cr(VI) contaminated site, a bentonite ratio of 2:10 is recommended for optimal natural performance of the natural clay-bentonite barrier. [ABSTRACT FROM AUTHOR]

The polymer obtained from hydrophilic monomers can be transformed into a hydrogel via cross-linking by different cross-linkers. Hydrogels are three-dimensional networks that can absorb several times their weight and swell in water/swelling media, improving the media's viscosity as a thickener. The cross-linked poly(acrylic acid) microparticles prepared via precipitation polymerization technique are often synthesized by radical polymerization and have carboxylic functional groups in their structure, which make the hydrogel properties such as swelling capacity, particle morphology, and viscosity be controlled by physical factors such as solvent, neutralizer, pH, pKa, zeta potential, and ionic strength of the swelling media, as well as synthetic factors including comonomer, cross-linker, and network type. In this paper, the effects of crucial factors on the synthetic and swelling steps are elaborated to facilitate the achievement of poly(acrylic acid)-based xerogels having desirable rheological properties, such as swelling/viscosity optimization, which is the primary purpose of a thickener in any swelling media. [ABSTRACT FROM AUTHOR]

The phage lysin field has done nothing but grow in the last decades. As a result, many different research groups around the world are contributing to the field, often with certain methodological differences that pose a challenge to the interpretation and comparison of results. In this work, we present the case study of three Acinetobacter baumannii‐targeting phage lysins (wild‐type endolysin LysMK34 plus engineered lysins eLysMK34 and 1D10) plus one lysin with broad activity against Gram‐positive bacteria (PlySs2) to provide exemplary evidence on the risks of generalization when using one of the most common lysin evaluation assays: the killing assay with resting cells. To that end, we performed killing assays with the aforementioned lysins using hypo‐, iso‐ and hypertonic buffers plus human serum either as the reaction or the dilution medium in a systematic manner. Our findings stress the perils of creating hypotonic conditions or a hypotonic shock during a killing assay, suggesting that hypotonic buffers should be avoided as a test environment or as diluents before plating to avoid overestimation of the killing effect in the assayed conditions. As a conclusion, we suggest that the nature of both the incubation and the dilution buffers should be always clearly identified when reporting killing activity data, and that for experimental consistency the same incubation buffer should be used as a diluent for posterior serial dilution and plating unless explicitly required by the experimental design. In addition, the most appropriate buffer mimicking the final application must be chosen to obtain relevant results. [ABSTRACT FROM AUTHOR]

Lead (Pb) is a heavy metal present in many agricultural fields, posing significant risks to the environment and public health. The mobility and leaching of Pb(II) in soils depend on soil characteristics. In agricultural soils, organic matter (OM) content has been reported as a crucial parameter influencing the leaching behavior of Pb(II). However, modeling the leaching behavior of Pb(II) in soils remains challenging, primarily due to the difficulty in obtaining soils that vary solely in OM content. In this study, the behavior of Pb(II) in artificial soils (ASs) was investigated, evaluating the effects of ionic strength, pH, and OM content. Additionally, the spatiotemporal distribution of the metal was explored using a multilevel factorial experimental design and column leaching experiments. The results indicate that lead retention capacity decreases with increasing ionic strength due to the increased leaching of OM, which forms complexes with Pb(II). The lead retention capacity of the soil is also affected by pH, with pH 7 inducing the highest retention. This modified the spatiotemporal distribution of the metal, which was analyzed using response surface methodology. A second-order polynomial model was obtained, allowing for the tracking of Pb(II) leaching in soils with 10% OM content. [ABSTRACT FROM AUTHOR]

• Electroosmosis in a poultice of kaolinite mixed with tap water has a higher EO flow rate than the poultice with calcium carbonate. • By increasing the concentration of calcium carbonate in the poultice of kaolinite, the EO flow rate decreases. • The EO flow stops when the calcium carbonate concentration increases to 80 % and 20 % of kaolinite in the poultice mixture. • The increase in ionic strength has a negative effect on EO flow. Electrokinetic treatment of masonry for desalination or electroosmotic dewatering depends on a poultice, in which the electrodes are placed, which fulfills several purposes. Poultice composed of kaolinite and CaCO 3 have been shown to have good workability and high pH buffering capacity. In this work, the electroosmotic (EO) permeability is studied in different kaolinite - CaCO 3 mixtures. In addition, the effect on EO of using NaCl as a mixing solution is investigated. A special cell is used to test the EO in the specimens. A phenomenological approach, based on the potential gradient and the flux of solution, was used to calculate the EO flow rate and EO permeability coefficient. Results showed that by increasing the concentration of CaCO 3 in the poultice mixture, the EO flow rate decreased and the poultice with 80 % CaCO 3 and more did not have any EO flow. Furthermore, the ionic strength in the mixing solution decreases the EO flow rate. [ABSTRACT FROM AUTHOR]

In the present study, the integration of magnetic dispersive micro-solid-phase extraction (MD-µSPE) with hollow fiber liquid-phase microextraction (HF-LPME) prior to gas chromatography–mass spectrometry (GC/MS) was developed to preconcentrate and determine trace amounts of chlorpyrifos pesticide. Azolla filiculoides fern biomass was loaded by magnetite nanoparticles to prepare magnetic adsorbent (azolla@Fe3O4). The structural characteristics of the produced magnetic nanocomposites (MNCs) were investigated by FESEM, TEM, VSM, FTIR, EDX, and XRD methods. In the proposed MD-µSPE/HF-LPME method, the adsorption/desorption variables in MD-µSPE step were optimized by Taguchi fractional factorial design. After chlorpyrifos adsorption in the optimized condition of MD-µSPE (Vsample = 50 mL, contact time = 15 min, solution pH = 3, adsorbent mass = 0.05 g, ionic strength = 0.01 mol L−1, and eluent type = ethanol), 2.0 mL of the desorbed ethanolic solution was added to 16 mL of 10% (w/v) NaCl aqueous solution for the next HF-LPME method and the final analysis was performed by GC/MS. The developed method showed a limit of detection of 0.05 μg L−1, a limit of quantification of 0.5 μg L−1, a dynamic linear range of 0.5–1000.0 μg L−1, preconcentration factors between 700 and 1050, and a repeatability (RSD%) of 6.9%. The suitability of the MD-µSPE/HF-LPME method was confirmed by measuring chlorpyrifos in real samples with relative recoveries in the range of 97.0–108.5%. The results showed good accuracy and precision of the developed MD-µSPE/HF-LPME method for the preconcentration and determination of trace amounts of chlorpyrifos in the aqueous samples. [ABSTRACT FROM AUTHOR]

In this work, polyanion polystyrene sulfonate modified laterite (PML) was used as an excellent material to remove ciprofloxacin (CFX) in water. The CFX adsorption on PML was affected by factors such as pH, PML dosage, contact time, ionic strength, and operating temperature. Under optimum conditions (pH 5; 150 min; 5 mg/mL, 10 mM NaCl, 25 °C) with an initial CFX concentration of 20 ppm, the maximum removal of CFX using PML reached greater than 96%. Langmuir isotherm model provided the best fit to the experimental results of the CFX adsorption process onto PML with the maximum capacity was 10.51 mg/g. Adsorption kinetics were in good agreement with pseudo-second-order. The ∆H0 value was − 12.090 kJ.mol−1, and the ∆G0 value was − 2.345 kJ.mol−1, declaring that the CFX adsorption onto PML was a spontaneous process and exothermal. Adsorption mechanisms of CFX on PML were controlled by both electrostatic interaction and non-electrostatic interaction. The adsorption constant in the Temkin model was 1.700 J/mol, and the energy value in Dubinin–Radushkevich model was 2.371 kJ/mol, proving that CFX adsorption on PML is a physical adsorption process. After five recycles, the CFX removal was still higher than 77%, while the CFX removal from wastewater was approximately 96%. [ABSTRACT FROM AUTHOR]

The growth process of chitosan/alginate polyelectrolyte films deposited by layer-by-layer assembly at different pH and ionic strength was studied in this work. The films were investigated using surface plasmon resonance (SPR) to examine the build-up kinetics, and atomic force microscopy (AFM) to visualize the surface topography. Each deposition step resulted in a progressive increase in mass. The film growth and thickness strongly depended on the polyelectrolyte charge density and complexation between the used polyelectrolytes. The film surface changed from smooth to rough when the pH increased. The results achieved could be used in estimating the potential of the multilayers to be applied as drug delivery systems. [ABSTRACT FROM AUTHOR]

Titrimetric methods were used to estimate the molar solubility and apparent acid dissociation constant (Kc) of salicylic acid in water. This was done with varied ionic strength values ranging from 0.00 to 0.75 mol·L−1 and over a temperature range of 15 to 60 °C. The thermodynamic dissociation constant (as pKa) of salicylic acid was found to be 2.985 at 25 °C. Within the measured temperature range, there was no consistent association between the pKa of salicylic acid and the temperature. The pKa values exhibited an inverse relationship with temperatures between 15 and 40 °C, while they showed a direct relationship with temperatures between 40 and 60 °C. Through the use of the Van't Hoff plot, the standard thermodynamic quantities (∆H°, ∆S°, and ∆G°) for the dissociation process of salicylic acid in water were calculated. For temperatures between 15 and 30 °C, these values were determined as 3.346 kJ·mol−1, − 19.99 JK−1·mol−1, and 9.306 kJ·mol−1 respectively. For the temperature range of 45 to 60 °C, the values were calculated as − 1.499 kJ·mol−1, − 27.06 kJ·K−1·mol−1, and 6.564 kJ·mol−1. The heat of solution (∆Hsol°) was computed using the Van't Hoff Isochore plot across the temperature range of 15 to 60 °C, resulting in a value of 15.03 kJ·mol−1. [ABSTRACT FROM AUTHOR]

The Mars 2020 Perseverance rover has explored fluvio‐lacustrine sedimentary rocks within Jezero crater. Prior work showed that igneous crater floor Séítah and Máaz formations have mafic mineralogy with alteration phases that indicate multiple episodes of aqueous alteration. In this work, we extend the analyses of hydration to targets in the Jezero western fan delta, using data from the SHERLOC (Scanning Habitable Environments with Raman and Luminescence for Organics and Chemicals) Raman spectrometer. Spectral features, for example, sulfate and hydration peak positions and shapes, vary within, and across the crater floor and western fan. The proportion of targets with hydration associated with sulfates was approximately equal in the crater floor and the western fan. All hydrated targets in the crater floor and upper fan showed bimodal hydration peaks at ∼3,200 and ∼3,400 cm−1. The sulfate symmetric stretch at ∼1,000 cm−1 coupled with a hydration peak at ∼3,400 cm−1 indicate that MgSO4·nH2O (2 < n ≤ 5) is a likely hydration carrier phase in all units, perhaps paired with low‐hydration (n ≤ 1) amorphous Mg‐sulfates, indicated by the ∼3,200 cm−1 peak. Low‐hydration MgSO4·nH2O (n = 1–2) are more prevalent in the fan, and hydrated targets in the fan front only had one peak at ∼3,400 cm−1. While anhydrite co‐occurs with hydrated Mg‐sulfates in the crater floor and fan front, hydrated Ca‐sulfates are observed instead at the top of the upper fan. Collectively, the data imply aqueous deposition of sediments with formation of salts from high ionic strength fluids and subsequent aridity to preserve the observed hydration states. Plain Language Summary: The Mars 2020 Perseverance rover has explored a fan delta deposit in the Jezero crater where a lake was present in the past. In this work, we use the SHERLOC (Scanning Habitable Environments with Raman and Luminescence for Organics and Chemicals) Raman spectroscopy instrument on the rover to determine the minerals that contain water in the form of H2O and/or OH. These hydrated minerals are indicators of interactions of rock with water and inform us how the environmental conditions and the habitability of Jezero crater evolved over time. Hydrated Mg‐sulfates MgSO4·nH2O (2 < n ≤ 5) are observed in both the crater floor and the western fan. Mg‐sulfates of lower hydration degree (n = 1–2) are more commonly found in the western fan, particularly the fan front. Hydrated Ca‐sulfate is found only close to the top of the fan. These changes in sulfate degree of hydration and/or cations from the floor to the fan are evidence of multiple past fluid events and chemistries at Jezero crater. Key Points: MgSO4·nH2O (2 < n ≤ 5) are found in the Jezero fan and floor while low‐hydration MgSO4·nH2O (n = 1–2) are more commonly found in the fanHydrated Ca‐sulfates are found only in the upper fanThe diverse phases imply salt formation from high ionic strength fluids and subsequent aridity to preserve the observed hydration states [ABSTRACT FROM AUTHOR]

The global increase in antibiotics consumption has caused hazardous concentrations of these antimicrobials to be present in soils, mainly due to the spreading of sewage sludge (or manure or slurry) and wastewater, and they could enter the food chain, posing serious risks to the environment and human health. One of these substances of concern is cefuroxime (CFX). To face antibiotics-related environmental pollution, adsorption is one of the most widely used techniques, with cost-effective and environmentally friendly byproducts being of clear interest to retain pollutants and increase the adsorption capacity of soils. In light of this, in this work, three low-cost bioadsorbents (pine bark, oak ash, and mussel shell) were added to different soil samples (at doses of 12 and 48 t/ha) to study their effects on the adsorption of CFX. Specifically, batch experiments were carried out for mixtures of soils and bioadsorbents, adding a range of different antibiotic concentrations at a fixed ionic strength. The results showed that the addition of pine bark (with pH = 3.99) increased the adsorption to 100% in most cases, while oak ash (pH = 11.31) and mussel shell (pH = 9.39) caused a clearly lower increase in adsorption (which, in some cases, even decreased). The Freundlich and linear models showed rather good adjustment to the experimental data when the bioadsorbents were added at both doses, while the Langmuir model showed error values which were too high in many cases. Regarding desorption, it was lower than 6% for the soils without bioadsorbents, and there was no desorption when the soils received bioadsorbent amendments. These results show that the addition of appropriate low-cost bioadsorbents to soils can be effective for adsorbing CFX, helping in the prevention of environmental pollution due to this emerging contaminant, which is a result of clear relevance to environmental and human health. [ABSTRACT FROM AUTHOR]

Prevention of biofilm formation is essential for water treatment and industrial processes. Although there are different agents capable to inhibit bacteria proliferation, the use of natural, and in particular obtained from waste, is highly desirable in the green chemistry paradigm. The objective of this work is to obtain eco-friendly sponges that can be used to prevent biofilm formation by the action of a natural antimicrobial agent. Polyvinylalcohol (PVA) sponges were prepared by freeze-drying using malic and citric acid as green crosslinkers. Aqueous lemon peel extract was used as antimicrobial agent for PVA dissolution. Some sponges were coated with polydimethylsiloxane (PDMS) in order to increase the stability in aqueous media and provide flexibility. Sponges were characterized by ATR-FTIR, TGA, DSC, nitrogen adsorption isotherms and SEM. Water contact angles and swelling degrees of all the prepared sponges were measured. Kinetic release measurements of the yellow pigment, present in the lemon extract, were analyzed under different pH and ionic strength conditions. The obtained sponges were incubated for 24 h at room temperature with Pseudomonas protegens. The surface of the sponges after incubation was characterized by Raman spectroscopy and observed at the microscope to determine the presence of biofilm. UV–Vis spectrophotometry with crystal violet were employed to quantify biofilm formation and optical density at 600 nm was measured in the liquid media to determine the bacterial cell concentration. Sponges show high mechanical and chemical resistance and incorporation of lemon extract prevent biofilm formation as high as 70% with respect to sponges without the extract. [ABSTRACT FROM AUTHOR]

Copyright of Food Research & Development is the property of Food Research & Development Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Baghdad Science Journal is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Nanobody has become an important tool for immunoassays because of its stability, specificity, and ease of expression. To monitor the aflatoxin M1 in dairy products, the anti-AFM1 nanobody, named M6, selected from the Bactrian camel AFM1 immune library, evaluated its properties, and developed an indirect competitive enzyme-linked immunosorbent assay (icELISA). After optimizing the parameters, including the blocking method, methanol concentrations, pH values, and ionic strength in the reaction system, a standard competitive inhibition curve was established, and methodological specificity and accuracy was verified. Results showed that Nb-M6 had a good affinity and thermal stability, the limit of detection (LOD) of Nb-icELISA was 0.111 ng/ mL, and the half maximal inhibitory concentration (IC50) was 1.498 ng/ mL. The recoveries of dairy products spiked were 89.8% - 104.1%, which were in agreement with the high-performance liquid chromatography (HPLC). The Nb-icELISA is simple, convenient and can be applied to batch screening of AFM1 in dairy products. [ABSTRACT FROM AUTHOR]

Biomolecular condensates have emerged as important structures in cellular function and disease, and are thought to form through liquid‐liquid phase separation (LLPS). Thorough and efficient in vitro experiments are therefore needed to elucidate the driving forces of protein LLPS and the possibility to modulate it with drugs. Here we present Taylor dispersion‐induced phase separation (TDIPS), a method to robustly measure condensation phenomena using a commercially available microfluidic platform. It uses only nanoliters of sample, does not require extrinsic fluorescent labels, and is straightforward to implement. We demonstrate TDIPS by screening the phase behaviour of two proteins that form biomolecular condensates in vivo, PGL‐3 and Ddx4. Uniquely accessible to this method, we find an unexpected re‐entrant behaviour at very low ionic strength, where LLPS is inhibited for both proteins. TDIPS can also probe the reversibility of assemblies, which was shown for both α‐synuclein and for lysozyme, relevant for health and biotechnology, respectively. Finally, we highlight how effective inhibition concentrations and partitioning of LLPS‐modifying compounds can be screened highly efficiently. [ABSTRACT FROM AUTHOR]

Iron and steel slags have a long history of both disposal and beneficial use in the coastal zone. Despite the large volumes of slag deposited, comprehensive assessments of potential risks associated with metal(loid) leaching from iron and steel by-products are rare for coastal systems. This study provides a national-scale overview of the 14 known slag deposits in the coastal environment of Great Britain (those within 100 m of the mean high-water mark), comprising geochemical characterisation and leaching test data (using both low and high ionic strength waters) to assess potential leaching risks. The seaward facing length of slag deposits totalled at least 76 km, and are predominantly composed of blast furnace (iron-making) slags from the early to mid-20th Century. Some of these form tidal barriers and formal coastal defence structures, but larger deposits are associated with historical coastal disposal in many former areas of iron and steel production, notably the Cumbrian coast of England. Slag deposits are dominated by melilite phases (e.g. gehlenite), with evidence of secondary mineral formation (e.g. gypsum, calcite) indicative of weathering. Leaching tests typically show lower element (e.g. Ba, V, Cr, Fe) release under seawater leaching scenarios compared to deionised water, largely ascribable to the pH buffering provided by the former. Only Mn and Mo showed elevated leaching concentrations in seawater treatments, though at modest levels (<3 mg/L and 0.01 mg/L, respectively). No significant leaching of potentially ecotoxic elements such as Cr and V (mean leachate concentrations <0.006 mg/L for both) were apparent in seawater, which micro-X-Ray Absorption Near Edge Structure (μXANES) analysis show are both present in slags in low valence (and low toxicity) forms. Although there may be physical hazards posed by extensive erosion of deposits in high-energy coastlines, the data suggest seawater leaching of coastal iron and steel slags in the UK is likely to pose minimal environmental risk. [ABSTRACT FROM AUTHOR]

Laponite® (LAP) is an intensively studied synthetic clay due to the versatility given by its layered structure, which makes it usable in various applications. This review describes the multifaceted properties and applications of LAP in aqueous dispersions and gel systems. The first sections of the review discuss the LAP structure and the interactions between clay discs in an aqueous medium under different conditions (such as ionic strength, pH, temperature, and the addition of polymers) in order to understand the function of clay in tailoring the properties of the designed material. Additionally, the review explores the aging phenomenon characteristic of LAP aqueous dispersions as well as the development of shake-gels by incorporating LAP. The second part shows the most recent studies on materials containing LAP with possible applicability in the drilling industry, cosmetics or care products industry, and biomedical fields. By elucidating the remarkable versatility and ease of integration of LAP into various matrices, this review underscores its significance as a key ingredient for the creation of next-generation materials with tailored functionalities. [ABSTRACT FROM AUTHOR]

The correct measurement of the resonance frequency and shell properties of coated microbubbles (MBs) is essential in understanding and optimizing their response to ultrasound (US) exposure parameters. In diagnostic and therapeutic ultrasound, MBs are typically surrounded by blood; however, the influence of the medium charges on the MB resonance frequency has not been systematically studied using controlled measurements. This study aims to measure the medium charge interactions on MB behavior by measuring the frequency-dependent attenuation of the same size MBs in mediums with different charge densities. In-house lipid-coated MBs with C3F8 gas core were formulated. The MBs were isolated to a mean size of 2.35 μm using differential centrifugation. MBs were diluted to ≈8×105 MBs/mL in distilled water (DW), Phosphate-Buffered Saline solution (PBS1x) and PBS10x. The frequency-dependent attenuation of the MBs solutions was measured using an aligned pair of PVDF transducers with a center frequency of 10MHz and 100% bandwidth in the linear oscillation regime (7 kPa pressure amplitude). The MB shell properties were estimated by fitting the linear equation to experiments. Using a pendant drop tension meter, the surface tension at the equilibrium of ≈6 mm diameter size drops of the same MB shell was measured inside DW, PBS1x and PBS10x. The surface tension at the C3F8/solution interface was estimated by fitting the Young-Laplace equation from the recorded images. The frequency of the peak attenuation at different salinity levels was 13, 7.5 and 6.25 MHz in DW, PBS1x and PBS-10x, respectively. The attenuation peak increased by ≈140% with increasing ion density. MBs' estimated shell elasticity decreased by 64% between DW and PBS-1x and 36% between PBS-1x and PBS-10x. The drop surface tension reduced by 10.5% between DW and PBS-1x and by 5% between PBS-1x and PBS-10x, respectively. Reduction in the shell stiffness is consistent with the drop surface tension measurements. The shell viscosity was reduced by ≈40% between DW and PBS-1x and 42% between PBS-1x and PBS-10x. The reduction in the fitted stiffness and viscosity is possibly due to the formation of a densely charged layer around the shell, further reducing the effective surface tension on the MBs. The changes in the resonance frequency and estimated shell parameters were significant and may potentially help to better understand and explain bubble behavior in applications. [ABSTRACT FROM AUTHOR]

In our prior paper, surface micelles with the core‐shell‐petal structure of the double hydrophilic block copolymer poly(N‐isopropylacrylamide)‐block‐poly[oligo(ethylene glycol) acrylate] (PNIPAM‐b‐POEGA) were successfully evaluated. In this work, ionic strength (under acidic conditions) and anion‐specificity effects (under neutral conditions) on the aggregation behavior of PNIPAM‐b‐POEGA at the air/water interface and the morphologies of its Langmuir–Blodgett (LB) films were systematically studied. Under acidic conditions, the salting‐out effect prevails over the electrostatic shielding effect, and the amide group shells with a slight protonation degree are covered up by the large POEGA petals. Under neutral conditions, the stretching degrees of POEGA blocks at low/moderate salt concentrations are close. At high salt concentrations, the isotherms gradually shift to large molecular areas in the order of the NaCl, Na2SO4, NaNO3, and NaSCN cases. The hysteresis degrees of the monolayers increase with the increase of salt concentrations due to the gradually increased interfacial stretching degree and compression‐induced underwater solubility of POEGA blocks. All the initial LB films of PNIPAM‐b‐POEGA exhibit isolated circular micelles with small cores. Upon compression, the LB films exhibit slightly large micelles because of the possible coalescence of some neighboring cores. [ABSTRACT FROM AUTHOR]

Phosphate removal from water through green, highly efficient technologies has received much attention. Biochar is an effective adsorbent for phosphate removal. However, adsorption capacity of phosphate on pristine rice straw-based biochar was not optimistic due to low anion exchange capacity. In this study, Fe-modified, Mg-modified and MgFe-modified rice straw-based biochar (Fe-BC, Mg-BC and MgFe-BC) were prepared by combining metal impregnation and biological template methods to improve the adsorption capacity of phosphate. The surface characteristics of biochar and the adsorption behavior of phosphate on biochar were investigated. The modified biochar had the specific surface area of 17.910–39.336 m2/g, and their surfaces were rich in a large number of functional groups and metal oxides. Phosphate release was observed on pristine rice straw-based biochar without metal impregnation. The maximum adsorption capacities of phosphate on MgFe-BC, Mg-BC and Fe-BC at 298 K were 6.93, 5.75 and 0.23 mg/g, respectively. Adsorption was a spontaneous endothermic process, while chemical adsorption dominated and electrostatic attraction and pores filling existed simultaneously. Based on the site energy distribution theory study, the standard deviation of MgFe-BC decreased from 6.96 to 4.64 kJ/mol with temperature increasing, which proved that the higher the temperature would cause the lower heterogeneity. Moreover, the effects of pH, humic acid, co-existing ions and ionic strength on phosphate adsorption of MgFe-BC were also discussed. MgFe-BC with fine pores and efficient adsorption sites is an ideal adsorbent for phosphate removal from water. [ABSTRACT FROM AUTHOR]

The kinetics of disproportionation of Pu(V) in EDTA solutions with pH 2.5–4.8 at a temperature of 45°C was studied using the spectrophotometric method. Pu(V) was obtained by reduction of Pu(VI) with EDTA ions. The rate of disproportionation in the pH range 2.9–4.8 is described by the equation d[Pu(V)]/dt = 2k[Pu(V)]2. With increasing pH the value of 2k decreases. In a solution of 28 mM EDTA at pH 2.91, 45°С, and an ionic strength of 0.09 and 1.0 M, 2k is 0.064 and 0.040 M–1 s–1, respectively. A dimer formed from PuO2+·5H2O and the PuO2HY2–·nH2O complex becomes an activated complex. Its decomposition leads to the appearance of Pu(IV) and Pu(VI). The latter, being bound to Y, is reduced intramolecularly to Pu(V). The activation energy is 86 kJ/mol (25–45°C). [ABSTRACT FROM AUTHOR]

Scaffolds offer a three-dimensional framework supporting cell growth, proliferation, and differentiation of cells which are used to repair and regenerate tissues. Recent advancements in scaffold technology have significantly exploited the field of tissue engineering and regenerative medicine. This comprehensive review provides in-depth exploration of scaffold materials, fabrication techniques, and their recent progress in applications. Composite scaffolds have promising applications in bone and dental tissue regeneration due to their greater mechanical properties and ability to promote cell growth. The inherent crosslinking present in hydrogels allows them to maintain their integrity and three-dimensional structure without dissolving. However, there is a growing interest in smart hydrogels which can respond to changes in their external surroundings like pH, ionic strength, temperature, or specific molecules. dECM scaffold is an alternative potential technique for reconstructing the functional organs/tissues by excluding the cell-associated antigens while maintaining the native ECM compositions like growth factors, basement membrane structural proteins, and GAG's. The degree of porosity in scaffolds can be increased by various fabrication techniques such as TIPS, SCPL, gas foaming, and freeze drying. GelMA hydrogels have shown promising potential in cell proliferation and tissue regeneration. In addition, graphene and its derivatives have been instrumental in the fabrication of bioactive scaffolds for cartilage regeneration. The introduction of additive manufacturing technologies, specifically 3D bioprinting, has significantly improved the precision and control of scaffold fabrication. [ABSTRACT FROM AUTHOR]

Reactive oxygen species are known to have a harmful activity in living systems. It attracts the attention of researchers due to their capability of damaging crucial biomolecules such as nucleic acids, lipids, proteins, polyunsaturated fatty acids, and carbohydrates and which results many human ailments: atherosclerosis, cancer, diabetes, inflammation, cardiovascular diseases, and neurological disorders. Hence, the investigation of the already known compounds exhibiting antioxidant properties is still an important scientific challenge. So reaction with Co(II)-bound superoxo complex, [(NH3)5Co(O2)Co(NH3)5]5+ (MBSC) and Popofol (PPF), Ferulic Acid (FA) is chosen to study the antioxidant activity of PPF and FA. Redox properties of Popofol (PPF) and Ferulic Acid (FA) which are two phenolic antioxidants are studied through the reduction of Co(II)-bound superoxo complex, [(NH3)5Co(O2)Co(NH3)5]5+ (MBSC) in aqueous acidic media ([H+] = 0.02–0.70 M) under pseudo-first-order condition. For both the PPF and FA, the observed rate increase with the increase in [PPF] and [FA] and the decrease with media [H+] and ionic strength, I. The kinetic analysis reveals that the deprotonated conjugate bases from PPF and FA reduces MBSC with the diffusion-controlled rate of ~ 108 and ~ 1011 M−1 s−1. Since, the decrease in ko values with increase in V/V D2O were not significant, we can propose for a simple electron-transfer (ET) mechanism, rather than proton-coupled electron transfer (PCET) or hydrogen-atom transfer (HAT) mechanism for the reduction in bound superoxide by PPF and FA. The antioxidant property of propofol and ferulic acid has been evaluated by various methods but in our study, the novelty lies on the exploration of the real insight of their antioxidant property by studying the chemical mechanism of their redox properties with MBSC. [ABSTRACT FROM AUTHOR]