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Surfactant‐assisted soil cleaning has been considered as a promising technology for remediating of dye‐contaminated soil, but is significantly impeded by limitations such as the adsorption or precipitation of surfactants in soil. To take the advantage of effective remediation of anionic surfactant and lower adsorption of nonionic surfactant, a remediation system has been developed in this study for soil contaminated with model dyes methyl orange and alizarin red, employing a designed anionic‐nonionic surfactant known as sodium nonylcyclohexanol ethoxylates sulfate (NCEO5S) and a commercial surfactant—sodium alkyl alcohol ethoxylate sulfate (AES). Using simple wash, the elution efficiency on highly‐contaminated soil (methyl orange and alizarin red) reached up to 94.34% and 97.66%, respectively, at 25°C in 24 h with 1 wt% of surfactant solution. Electrostatic repulsion noticeably mitigates surfactant adsorption on the soil surface. The low adsorption of surfactants on the eluted soil surface was characterized with SEM‐EDS and thermogravimetric analysis. The kinetics of surfactant‐enhanced dyes desorption from contaminated soil follow the Elovich equation. The findings will be benefit for developing eco‐friendly surfactant systems to clean‐up dyes‐contaminated soils while minimizing surfactant adsorption. [ABSTRACT FROM AUTHOR]

Talc is a naturally hydrophobic mineral. Its separation from sulfide minerals is a tough issue in froth flotation. In this study, calcium lignosulphonate (CLS) was introduced as a talc depressant during sodium isobutyl xanthate (SIBX) flotation of chalcopyrite. The micro-flotation findings showed that under pH 5.0–10.5, the combination application of CLS and SIBX achieved a selective flotation separation of chalcopyrite from talc. The results of zeta potential, contact angle, adsorption capacity and in-situ AFM deduced that both talc and chalcopyrite exhibited a favorable affinity toward CLS, and SIBX hardly changed the adsorption of CLS on talc surface, while significantly reduced that on chalcopyrite. The Ca2+ ions of CLS played a bridging role in connecting lignosulphonate (LS) anions and the negatively charged Si-O layers through electrostatic attraction, which transformed talc surface from hydrophobicity into hydrophilicity. The Cl− ions weakened the adsorption of LS anions on the Ca2+-modified talc surface, and the adsorption affinity of Na+ ion toward the Si-O layers was much weaker than that of Ca2+ ion. Thus, CLS exhibited the strongest depression against talc's floatability, followed by CaCl2 + SLS (sodium lignosulphonate), and then SLS. SIBX chemisorbed on to chalcopyrite via forming the surface Cu-IBX complexes, which removed the adsorbed LS anions and recovered the floatability of chalcopyrite. The CLS-hydrophilized talc and SIBX-hydrophobized chalcopyrite exhibited the different surface wettability, and they both loaded negative charges, which prevented the aggregation of their particles, resulting in a highly efficient flotation separation chalcopyrite from talc. [ABSTRACT FROM AUTHOR]

In this paper, a colloidal dispersion at different pH containing soybean protein isolate (SPI) microgel particles and xanthan gum (XG) was used as the aqueous phase to prepare O/W emulsion gels with soybean oil. Properties of SPI microgel particles were analyzed by particle size, Zeta‐potential, secondary structure, optical contact angle, dynamic interface tension, and SEM testing, respectively. Results showed that pH impact microgels particle size and Zeta‐potential and their emulsification properties. It turned out that only at pH 3, 6, 7, and 8 can construct emulsions successfully. Based on a comparison of microstructure and macroscopic properties, it was found that at pH 3, proteins and polysaccharides were oppositely charged, electrostatic attraction between them reduced proteins located at the interface, and was more likely to form larger droplets, resulting in a bimodal droplet distribution and larger sizes. Conversely, at the pH of 6, 7, and 8, respectively, emulsions exhibited a uniform droplet distribution and more solid‐like rheological properties due to the powerful electrostatic repulsion between SPI and XG. Also, emulsion gels co‐stabilized with proteins and polysaccharides under electrostatic repulsion conditions showed an ideal recovery ability. Overall, this work would be beneficial to the use of emulsion gels in fat substitute systems. [ABSTRACT FROM AUTHOR]

Electrolysis of seawater represents great potentials for sustainable hydrogen production. However, both competitive Cl− adsorption and catalysts corrosion caused by chlorine oxidation reaction (ClOR) are major challenges in seawater electrolysis. Inspired by the concept of hard and soft acids and bases (HSAB), polyphosphate oxyanions (P3O105−) on Ni(OH)2 surface is coordinated to obtain harder acid Ni sites, which could obtain 160 times stability enhancement compared to pure Ni(OH)2 for oxygen evolution reaction (OER) in alkaline seawater at 800 mA cm−2. Also, the turnover frequency value on Ni(OH)2‐P3O105− is 50 times that on Ni(OH)2, implying higher intrinsic OER activity of Ni(OH)2‐P3O105−. Theoretical and experimental investigations show that P3O105− could facilitate transition of Ni3+ to harder acid Ni>3+, thus preferring adsorption of hard base OH− rather than soft base Cl−. This could enhance OER selectivity and inhibit undesirable ClOR. Furthermore, molecular dynamics simulations indicate that the Cl− concentration near the electrode could be reduced by nearly half due to electrostatic repulsion of Cl− by surface P3O105− oxyanions. When assembled into an electrolyzer for alkaline seawater splitting, it could operate at 2.2 V with large current up to 1.4 A for 240 h. [ABSTRACT FROM AUTHOR]

Ultrasmall silica colloid particles (SCPs) show broad applications in various fields, including cosmetics, paint, medicine, and electronics. However, the precise and scalable synthesis of ultrasmall SCPs remains challenging. This study introduces a facile polymer-based strategy for the synthesis of ultrasmall SCPs through the synergistic utilization of solvophobic interactions and electrostatic repulsion. The size of SCPs can be efficiently modulated by the ratio between solvophilic and solvophobic segments within random copolymers. This approach allows for producing SCPs with a diameter of down to 9.6 ± 1.7 nm and a solid content of up to 9.8%. Furthermore, amphiphilic SCPs were obtained by introducing PEO blocks into copolymer templates and modifying with long carbon chain silane coupling agent. [ABSTRACT FROM AUTHOR]

Seawater electrolysis, especially in coastlines, is widely considered as a sustainable way of making clean and high-purity H2 from renewable energy; however, the practical viability is challenged severely by the limited anode durability resulting from side reactions of chlorine species. Herein, we report an effective Cl− blocking barrier of NiFe-layer double hydroxide (NiFe-LDH) to harmful chlorine chemistry during alkaline seawater oxidation (ASO), a pre-formed surface-derived NiFe-phosphate (Pi) outer-layer. Specifically, the PO43−-enriched outer-layer is capable of physically and electrostatically inhibiting Cl− adsorption, which protects active Ni3+ sites during ASO. The NiFe-LDH with the NiFe-Pi outer-layer (NiFe-LDH@NiFe-Pi) exhibits higher current densities (j) and lower overpotentials to afford 1 A·cm−2 (η1000 of 370 mV versus η1000 of 420 mV) than the NiFe-LDH in 1 M KOH + seawater. Notably, the NiFe-LDH@NiFe-Pi also demonstrates longer-term electrochemical durability than NiFe-LDH, attaining 100-h duration at the j of 1 A·cm−2. Additionally, the importance of surface-derived PO43−-enriched outer-layer in protecting the active centers, γ-NiOOH, is explained by ex situ characterizations and in situ electrochemical spectroscopic studies. [ABSTRACT FROM AUTHOR]

MXene‐based films are prevalent in a variety of applications owing to their advantages such as high metallic conductivity and unique mechanical properties. However, the stability issue is the primary drawback that greatly constrains their practical applications. In this study, an MXene‐based film featuring excellent stability, high conductivity, and remarkable flexibility is designed and fabricated. It is worth noting that this film, denoted as MX‐GO(l/s), is afforded via the rational combination of mixed‐sized graphene oxide (GO) nanosheets with MXene layers. Comprehensive explorations reveal that compact and highly dense structures are formed in MX‐GO(l/s), which is ascribed to the synergistic effect of both electrostatic repulsion and intercalation. Furthermore, the exceptional stability of MX‐GO(l/s) is demonstrated by the high retention rates in conductivity under a 90‐day exposure in air and a 12‐h immersion in seawater, which are determined as 98% and 92%, respectively. The radio frequency identification (RFID) antenna based on MX‐GO(l/s) is fabricated and evaluated, showing great potential in practical applications. This study paves the way for the further development of MXene‐based films via controlled addition of the second phase, which is beneficial for their broad application prospects. [ABSTRACT FROM AUTHOR]

Bipolar membranes (BPMs) have emerged as a promising solution for mitigating CO2 losses, salt precipitation and high maintenance costs associated with the commonly used anion‐exchange membrane electrode assembly for CO2 reduction reaction (CO2RR). However, the industrial implementation of BPM‐based zero‐gap electrolyzer is hampered by the poor CO2RR performance, largely attributed to the local acidic environment. Here, we report a backbone engineering strategy to improve the CO2RR performance of molecular catalysts in BPM‐based zero‐gap electrolyzers by covalently grafting cobalt tetraaminophthalocyanine onto a positively charged polyfluorene backbone (PF‐CoTAPc). PF‐CoTAPc shows a high acid tolerance in BPM electrode assembly (BPMEA), achieving a high FE of 82.6 % for CO at 100 mA/cm2 and a high CO2 utilization efficiency of 87.8 %. Notably, the CO2RR selectivity, carbon utilization efficiency and long‐term stability of PF‐CoTAPc in BPMEA outperform reported BPM systems. We attribute the enhancement to the stable cationic shield in the double layer and suppression of proton migration, ultimately inhibiting the undesired hydrogen evolution and improving the CO2RR selectivity. Techno‐economic analysis shows the least energy consumption (957 kJ/mol) for the PF‐CoTAPc catalyst in BPMEA. Our findings provide a viable strategy for designing efficient CO2RR catalysts in acidic environments. [ABSTRACT FROM AUTHOR]

Developing high‐performance nanofluidic fibers with synergetic ionic and electric conductivities is promising for human–machine interface interaction. In such a scenario, inter‐ and intra‐forces in constituent flakes are recognized as crucial factors in determining the derived nanofluidic fiber performance. In this work, the rheological properties of Ti3C2Tx MXene solution are systematically optimized by regulating the electrostatic interaction via introducing multivalent metal cations. As a result, such multivalent cations trigger ionic crosslinking and remarkably strengthen the interaction force between nanosheets, which even forms into a tight fiber‐shaped gel network. A series of cations, such as K+, Na+, Mg2+, Zn2+, and Al3+, are introduced to enhance the ionic cross‐linking between interconnected flakes. The thus‐prepared Zn2+‐Ti3C2Tx fiber exhibits a remarkable electrical conductivity of 11 200 S cm−1, a tensile strength of 252 MPa, and an ionic conductivity of 2.51 × 10−3 S cm−1. This multivalent cation crosslinking strategy could offer some insights into developing functional nanofluidic fibers for wearable or healthcare applications. [ABSTRACT FROM AUTHOR]

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OH− sieving membranes provide a valuable means for treating alkaline effluents but their development presents several challenges. In this study, the concept of ionization engineering is applied to two‐dimensional (2D) laminated membranes to facilitate OH− separation. This concept is demonstrated through the stacking of the self‐designed sulfonated graphene oxide (SGO) nanosheets to fabricate 2D membranes. The SGO membranes enhance synergistically the OH− dialysis coefficients and separation factors when treating simulated NaOH/Na2WO4 alkaline wastewater, compared with the performance of 2D GO membranes and commonly adopted polymeric cation exchange membranes. Furthermore, the separation factor achieved by the SGO membranes is considerably higher than that of most of the existing alkali recovery membranes. Results of molecular dynamics simulations indicate that the high efficiency of OH− separation in the 2D SGO confined channels is attributable to dehydration effects and intensified electrostatic repulsion. Overall, this research provides an alternative strategy for achieving rapid OH− sieving through the ionization of 2D confined channels. [ABSTRACT FROM AUTHOR]

Seawater electrolysis is an attractive way of making H2 in coastal areas, and NiFe‐based materials are among the top options for alkaline seawater oxidation (ASO). However, ample Cl− in seawater can severely corrode catalytic sites and lead to limited lifespans. Herein, we report that in situ carbon oxyanion self‐transformation (COST) from oxalate to carbonate on a monolithic NiFe oxalate micropillar electrode allows safeguard of high‐valence metal reaction sites in ASO. In situ/ex situ studies show that spontaneous, timely, and appropriate COST safeguards active sites against Cl− attack during ASO even at an ampere‐level current density (j). Our NiFe catalyst shows efficient and stable ASO performance, which requires an overpotential as low as 349 mV to attain a j of 1 A cm−2. Moreover, the NiFe catalyst with protective surface CO32− exhibits a slight activity degradation after 600 h of electrolysis under 1 A cm−2 in alkaline seawater. This work reports effective catalyst surface design concepts at the level of oxyanion self‐transformation, acting as a momentous step toward defending active sites in seawater‐to‐H2 conversion systems. [ABSTRACT FROM AUTHOR]

Lithium‐sulfur batteries are believed to possess the feasibility to power electric vehicles in the future ascribed to the competitive energy density. However, soluble polysulfides continuously shuttle between the sulfur electrode and lithium anode across the separator, which dramatically impairs the battery's capacity. Herein, the surface of a polypropylene separator (PP film) is successfully modified with a delicately designed cation‐selective polymer layer to suppress the transport of polysulfides. In principle, since bis‐sulfonimide anions groups on the backbone of the polymer are immobilized, only cations can pass through the polymer layer. Furthermore, plenty of ethoxy chains in the polymer can facilitate lithium‐ion mobility. Consequently, in addition to obstructing the movement of negatively charged polysulfides by the electrostatic repulsive force of fixed anions, the coated multi‐functional layer on the PP film also guarantees the smooth conduction of lithium ions. The investigations demonstrate that the battery with the pristine PP film only delivers 228.5 mAh g−1 after 300 cycles at 2 C with a high capacity fading rate of 60.9 %. By contrast, the polymer‐coated sample can release 409.4 mAh g−1 under the identical test condition and the capacity fading rate sharply declines to 43.2 %, illustrating superior cycle performance. [ABSTRACT FROM AUTHOR]

Vanadium redox flow batteries (VRFBs) are promising candidates for large-scale energy storage, and the electrolyte plays a critical role in chemical–electrical energy conversion. However, the operating temperature of VRFBs is limited to 10–40 °C because of the stability of the electrolyte. To overcome this, various chemical species are added, but the progress and mechanism have not been summarized and discussed yet. This review summarizes research progress on electrolyte additives that are used for different purposes or systems in the operation of VRFBs, including stabilizing agents (SAs) and electrochemical mass transfer enhancers (EMTEs). Additives in vanadium electrolytes that exhibit microscopic stabilizing mechanisms and electrochemical enhancing mechanisms, including complexation, electrostatic repulsion, growth inhibition, and modifying electrodes, are also discussed, including inorganic, organic, and complex. In the end, the prospects and challenges associated with the side effects of additives in VRFBs are presented, aiming to provide a theoretical and comprehensive reference for researchers to design a higher-performance electrolyte for VRFBs. [ABSTRACT FROM AUTHOR]

Although lithium metal has become a promising anode material for high-energy batteries owing to its high specific capacity and the lowest reduction potential, the continuous side reactions with electrolyte as well as the safety problem caused by Li dendrite growth restrict Li anode's practical application. Herein, we demonstrate that N-fluoropyridinium (ArF+) bis(trifluoromethane)sulfonimide (TFSI−) as an electrolyte additive can protect the lithium metal by both solid electrolyte interphase (SEI) protection and electrostatic repulsion mechanisms. The ArF+ cations not only participate in forming F, N-containing SEI protective layer on Li surface, but also act as a cationic repellent during Li deposition to inhibit Li dendrite growth. As a result, the cycle performance of Li symmetric cells and Li∥LiFePO4 full cells were significantly improved by using ArFTFSI-added electrolyte. This study provides an electrolyte additive strategy for Li anode realizing SEI protection and electrostatic repulsion simultaneously. [ABSTRACT FROM AUTHOR]

[Display omitted] In this work, we found that the presence of non-active ZnO crystals greatly accelerated the degradation of Bisphenol A (BPA) by 3.7 folds in the peroxymonosulfate (PMS, HSO 5 −)/Co 3 O 4 system. Our mechanistic study revealed that the ZnO particles would create negative electric microfields around them, which are closely related with the zeta potentials (ζ) of ZnO and affected by solution pH. According to COMSOL simulation, the electrostatic repulsion between ZnO and PMS would drive HSO 5 − toward active Co 3 O 4 surface, leading to the concentration increasing of HSO 5 − around active Co 3 O 4 particles, which will then improve the degradation performance. The particle size of ZnO will also affect the promoting effect greatly by COMSOL simulation. Therefore, this study for the first time reveals synergy of electric microfields for enhanced heterogeneous Fenton-like reactions, providing a low-cost and effective strategy for enhanced persulfate catalysis. [ABSTRACT FROM AUTHOR]

Action model of aggregation and disaggregation between serpentine and pyrite in the presence of HEDP or SIBX. [Display omitted] Hypothesis: In xanthate flotation system, the aggregation of serpentine on sulfide minerals significantly weakened their floatability. And it was generally assumed that the electrostatic attraction was of the dominant driver for coating of serpentine slimes. In this paper, the hydrophobic interaction between the "talc-like" cleavage plane of serpentine and the xanthate-hydrophobized surface of sulfide minerals was proposed as the dominated driver. Experiments: To evaluate the aggregation of serpentine on pyrite surface, a novel experimental protocol was designed, and the aggregation behavior and mechanism in the absence and presence of sodium isobutyl xanthate (SIBX) were explored through in situ optical microscope, micro-flotation, contact angle, zeta potential and FT-IR. Afterwards, the disaggregation mechanism of 1-hydroxyethylidene-1,1-diphosphonic acid (HEDP) to the aggregates of serpentine on pyrite surface was revealed. Findings: The electrostatic attraction facilitated the slight aggregation of serpentine slimes on bare pyrite surface. The hydrophobic interaction between the "talc-like" plane of serpentine and SIBX-covered pyrite significantly promoted the aggregation between them, which remarkably weakened the floatability of pyrite. The attendance of HEDP anions reversed the surface potential of the octahedral Mg-O layers of serpentine from the positive into the negative, thus to prevent the aggregation of the HEDP-anchored serpentine with the SIBX-covered pyrite via the strong electrostatic repulsion between them. As a result, the disaggregation as well as SIBX flotation separation of pyrite from serpentine was realized. This investigation also provided new insights into the aggregation and disaggregation between serpentine and sulfide minerals during froth flotation. [ABSTRACT FROM AUTHOR]

[Display omitted] • The conductive and hydrophilic membrane was prepared by cross-linking reaction. • This membrane could resist bio-fouling with the assistance of electrical chemistry. • The stability and performance of this membrane were evaluated in bioreactor. The anaerobic membrane bioreactor has great potentials to treat the wastewater with high organic matter due to the efficient anaerobic digestion process and high biomass retention. However, the existence of membrane fouling significantly increases the maintenance cost, and always requires frequent and complex cleaning process to recover the membrane performance. Thus, it is significant to fabricate a membrane with excellent anti-fouling performance for the application in membrane bioreactors. Herein, we prepared the CNTs-PVDF hollow fiber membrane with fouling resistance via loading the conductive CNTs coating on the surface of commercial PVDF membrane by a simple cross-linking reaction with hydrophilic polyvinyl alcohol and succinic acid. "Dual defense" was constructed by the combination of the hydrophilic surface and conductive CNTs coating, which lifted the anti-fouling performance of this membrane. In the assistance of electrical effect, the permeance of the membrane with −1.2 V bias could be recovered to 95 % of original state by simple hydraulic cleaning, while that of the membrane without bias was only 58 % after filtrating the sludge of 2000 mg/L. Furthermore, this membrane also exhibited the superior stability and fouling resistance in the operation of anaerobic electrochemical membrane bioreactor, which was promising for the advanced water treatment. [ABSTRACT FROM AUTHOR]

The impeded mass transfer rate by on-site-generated gas bubbles at both cathode and anode dramatically reduces the energy conversion efficiency of the proton exchange membrane water electrolyzer (PEMWE). Herein, we report a surfactant-assistant method to accelerate the nano/micro-bubble detachment and the mass transfer rate by reducing the surface tension, resulting in an increase in overall efficiency. Four kinds of surfactants are studied in this work. Only potassium perfluorobutyl sulfonate (PPFBS), which has the structural similarity to Nafion, shows a significant promotion of activity and stability for both hygrogen evolution reaction (HER) and oxygen evolution reaction (OER) in the acidic medium at the high current density region. The HER overpotential at 0.1 A·cm−2 decreased 22%, and the current density at −0.4 V increased 31% by adding PPFBS. The promotion of overall efficiency by PPFBS on a homemade PEMWE was also proven. The reduced surface tension and electrostatic repulsion were the probable origins of the accelerated bubble detachment. [ABSTRACT FROM AUTHOR]

[Display omitted] • Hydrodynamic interactions (HI) affect the aggregation dynamics of colloids straddling a fluid–fluid interface. • For uncharged particles, HI decrease the probability of aggregate formation for all Péclet (Pe) numbers. • For charged particles, HI change the probability of aggregate formation depending on the relative magnitude and influence of electrostatic repulsive interactions. The cluster formation and self-assembly of floating colloids at a fluid/fluid interface is a delicate force balance involving deterministic lateral interaction forces, viscous resistance to relative colloid motion along the surface and thermal (Brownian) fluctuations. As the colloid dimensions get smaller, thermal forces and associated drag forces become important and can affect the self assembly into ordered patterns and crystal structures that are the starting point for various materials applications. Langevin dynamic simulations for particle pairs straddling a liquid–liquid interface with a high viscosity contrast are presented to describe the lateral interfacial assembly of particles in Brownian and non-Brownian dominated regimes. These simulations incorporate capillary attraction, electrostatic repulsion, thermal fluctuations and hydrodynamic interactions (HI) between particles (including the effect of the particle immersion depth). Simulation results are presented for neutrally wetted particles which form a contact angle θ = 90 0 at the interface. The simulation results suggest that clustering, fractal growth and particle ordering become favorable outcomes at critically large values of the Pe numbers, while smaller Pe numbers exhibit higher probabilities of final configurations where particle motion remains uncorrelated in space and particle pairs are found to be more widely separated especially upon the introduction of HI. [ABSTRACT FROM AUTHOR]

[Display omitted] Oil-in-dispersion emulsions can be stabilized by like charged particles and surfactant. Surfactant adsorbs at the oil–water interface to reduce the interfacial tension and endow the interface with charge, while particles remain dispersed in the aqueous phase to provide electrostatic repulsion between droplets and particles. Can weakly surface-active organic electrolytes adsorb at the oil–water interface and behave like surfactants in stabilizing oil-in-dispersion emulsions with like charged particles? Symmetrical organic electrolytes, tetraalkylammonium bromides (R 4 NBr), with either no or very low interfacial activity endowing oil droplets with charge were combined with alumina nanoparticles to stabilize emulsions. The effect of R chain length (varying from methyl to butyl) on the type and stability of emulsions was investigated. Mixtures of high concentrations of short chain R 4 NBr salts (R = methyl or ethyl) and alumina particles stabilise oil-in-water Pickering emulsions, whereas longer chain (R = propyl or butyl) analogues stabilize oil-in-dispersion emulsions assisted by alumina particles. Tetrapropylammonium and tetrabutylammonium cations adsorb at the oil–water interface reducing the interfacial tension and endowing the interface with charge. The stability of the oil-in-dispersion emulsions is dominated by the electrostatic repulsion between the droplets and between droplets and particles in the continuous aqueous phase. [ABSTRACT FROM AUTHOR]

Interventional catheters have been widely applied in diagnostics, therapeutics, and other biomedical areas. The complications caused by catheter-related bacterial infection, venous thrombosis, and vascular abrasion have become the main reasons for the failure of interventional therapy. In this study, polyacrylamide/poly(acrylic acid) lubricating copolymer brushes were constructed on the surface of catheters and efficiently resisted the adhesion of blood components and bacteria through hydration and electrostatic repulsion effects. The copolymer brushes are surface-independently constructed on various substrates through a three-step method. The brushes achieve effective lubricating, antiadhesion, and antibacterial properties. Particularly, the 2PAM/6PAA brushes exhibited the most excellent overall performance with a 94% reduction in coefficient of friction, 87.2 and 78.3% reduction in adhesion levels of bovine serum albumin and bovine blood fibrin, and 92.3, 97.1, and 93.5% reduction in adhesion levels of Staphylococcus aureus , Pseudomonas aeruginosa , and Escherichia coli . The 2PAM/6PAA brushes significantly reduced the adhesion of blood components in the in vitro blood circulation test, demonstrating its practical application efficacy. Additionally, experiments and molecular dynamics simulations were used to reveal the antiadhesion mechanism of the brushes. Thus, the copolymer brushes in this work show great potential in the antithrombotic, antibacterial, and lubrication modification for medical devices contacting with blood.

Purpose: The purpose of this study is to develop a method for selecting uniform wave vectors for double diffusion encoding (DDE) to improve the accuracy and reliability of diffusion measurements., Methods: The method relies on identifying orthogonal wave vectors with rotations, and representing these rotations as points on a three-dimensional sphere in four dimensions using quaternions. This enables an electrostatic repulsion algorithm to achieve a uniform distribution of these points. The optimal points are then converted back into orthogonal wave vectors (or rotations)., Results: The method was validated by comparing the distribution of directions to those generated by uniform sampling and by evaluating the error in the powder-averaged signal for various models. Our results demonstrate that the electrostatic repulsion approach effectively achieves a uniform distribution of wave vectors., Conclusion: The proposed method provides a systematic way to generate uniform diffusion directions suitable, for example, for DDE, enhancing the precision of diffusion measurements and reducing potential bias in experimental results. The method is also capable of generating uniform sets of B-tensors, and is thus applicable for general free waveform encoding., (© 2024 International Society for Magnetic Resonance in Medicine.)

Nanofiltration (NF) effectively removes per- and polyfluoroalkyl substances (PFAS) from water but struggles with short-chain PFAS (i.e., those containing less than 6 perfluorinated carbons) due to size exclusion inefficiency. In this study, we developed layer-by-layer assembled NF membranes with PDADMAC/PSS terminal bilayers varying in chain lengths, hydrophilicity, and charge, and systematically assessed their removal of 16 representative PFAS species. The mechanisms between long-chain and short-chain PFAS were investigated and optimal strategies for enhancing PFAS selectivity were developed. Results demonstrated that the (PDADMAC/PSS) 3 membrane achieved the highest removal (86.1%-98.1%) for short-chain PFAS, including PFBA-PFHpA (C4-C6), PFBS (C4), PFMOPrA (C3), PFMOBA (C4), and GenX (C5), while effectively removing (>99.9%) long-chain counterparts (≥C7). As feed water pH increased from 3.5 to 9.0, average PFAS rejection rose from 16.6% to 32.0%, revealing more negative charged membrane surface endow stronger electrostatic repulsion, particularly for short-chain anionic PFAS. In addition, we also tested the PFAS removal efficacy of (PDADMAC/PSS) 3 membrane using real sewage plant effluent. Compared to the pristine membrane, the (PDADMAC/PSS) 3 membrane exhibited improved removal for most PFAS, with removal efficiencies ranging from 82.5% for PFOA to 96.7% for PFOS. The most significant improvements were observed in C4 compounds like PFBA and PFBS (increased by 6.0-11.5%). Our study suggests that PFAS removal efficiency by NF highly depends on size exclusion, with short-chain anionic PFAS more likely affected by electrostatic repulsion. Membrane surface manipulation can enhance selectivity, aiding in predicting NF treatment effectiveness for specific PFAS compounds., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

This study aimed at investigating the effective removal of cationic dye (methylene blue) and multivalent cation by a novel positively charged nanofiltration composite membrane. This nanofiltration membrane was made by incorporating two types of amino-metal--organic frameworks named MIL-101(Al)-NH2 and MIL-101(Cr)-NH2 with a positive charge as fillers into polyvinyl alcohol polymeric matrix. Optimal concentration of the polyvinyl alcohol and filler was evaluated to enhance removal efficiency of particles. Fillers could homogeneously spread in polyvinyl alcohol aqueous solution and form a thin layer above the polysulfone substrate. The effect of metal--organic framework types and their content on the membrane structure were studied by X-ray diffraction, Fourier-transform infrared spectroscopy, field-emission scanning electron microscopy, zeta potential and water contact angle. The filler morphology and its content into polyvinyl alcohol matrix (0%-20%) affected significantly on membrane performance and fouling. MIL-101(Al)-NH2 had a smaller structure than grainy MIL-101(Cr)-NH2. The results showed that the membrane filled with MIL-101(Al)-NH2 achieved higher flux permeability and rejection compared with that of filled with MIL-101(Cr)-NH2. Although the membrane permeate flux was approximately 15 L/m² h with a reasonable fouling and cleaning properties, this MIL- 101(Al)-NH2/polyvinyl alcohol nanofiltration membranes could reject up to 99% of methylene blue because of electrostatic repulsion effect. It is suggested that the fabricated nanofiltration membrane be used to purify dilute amounts of cationic dye [ABSTRACT FROM AUTHOR]

Surfactants are widely used to improve the solubility of oil in water in petrochemical, making it more difficult to remove oil–water emulsions during the water treatment process. Electrocoagulation (EC) is an appropriate method for treating oily wastewater and destabilizing emulsions. However, the demulsification mechanism of oil–water droplets emulsified by surfactants with different charges have not been investigated systematically. The demulsification performance of electrocoagulation on emulsions wastewater containing cationic, non-ionic, and anionic surfactants was studied. The results showed that the removal rate of total organic carbon (TOC) in oily wastewater with anionic surfactant by EC reached 92.98% ± 0.40% at a current density of 1 mA/cm2, while that of the non-ionic surfactant was 84.88% ± 0.63%. The characterization of flocs showed that EC has the highest coagulation and demulsification of oil droplets with a negative charge on the surface (−70.50 ± 10.25 mV), which indicated that the charge neutralization of oil droplets was beneficial for the destabilization of the formed oily flocs. However, when the zeta potential of the oil droplets reached 75.50 ± 1.25 mV, the TOC removal efficiency was only 11.80% ± 1.43%. The TOC removal could achieve 33.23% ± 3.21% when the current density improved from 1 mA/cm2 to 10 mA/cm2. The enhanced removal was due to the sweep coagulation rather than charge neutralization. This study provides a fundamental basis for the electrochemical treatment of oily wastewater. [ABSTRACT FROM AUTHOR]

Quinoa protein has high nutritional value, containing all the essential amino acids, but its weak gelling property limits its processing and application. The fibrillar aggregates of plant proteins formed at pH 2 can improve the gelling property, but the fibrils dissociate as the pH values shift. Here, we found that green enzymatic hydrolysis at pH 7 could substitute acid hydrolysis to generate thermal-induced fibrillar aggregates from quinoa protein isolate (QPI). When the enzyme to substrate ratio (E/S) increased to 0.075%, the electrostatic repulsion increased, but the hydrophobic interaction did not vary significantly, and the formation of fibrillar aggregates was favored by the synergistic effect of these two molecular driving forces. Whereas a continuous increase in the E/S resulted in fewer fibrillar aggregates, which was due to the decreased electrostatic repulsion and enhanced hydrophobic interaction. Furthermore, when the E/S was 0.075%, the parallel β-sheet content increased and the length of fibrillar aggregates extended from 175 nm to 327 nm as the concentration of CaCl 2 increased from 0 to 120 mmol/L. The coordination between Ca2+ and carboxyl groups could be bridging mode. However, the increase of CaCl 2 concentration to 160 and 200 mmol/L caused fibrillar aggregates to cluster and become shorter due to the electrostatic shielding effects, leading to the decreased gelling properties. Here, we presented an innovative method to prepare QPI fibrillar aggregates at neutral condition, and it showed limited bromelain hydrolysis and appropriate CaCl 2 addition could improve the gelation of QPI by regulating its fibrillation. [Display omitted] • Enzymatic hydrolysis promoted the formation of fibrillar aggregates at pH 7. • Enhanced electrostatic repulsion induced by hydrolysis facilitated the fibrillation. • CaCl 2 was conducive to form irreversible protein fibrils and elongated their length. • Longer fibrillar aggregates improved the gelling properties of quinoa protein. [ABSTRACT FROM AUTHOR]

Salt cavern gas storage is one of the vital strategic natural gas reserves and emergency peak shaving facilities all over the world. However, rock salt in China is primarily bedded salt, usually composed of many thin salt layers and interlayers (e.g., anhydrite, mudstone, and glauberite). During the water solution mining process of the cavern, the insoluble mudstones fall to the bottom and account for 1/3 up to 2/3 of the storage capacity. The bulk volume of the insoluble mudstones is almost twice its in-suit volume. It is of great urgency to investigate the swelling mechanisms of the bottom insoluble mudstones. Given this, we first analyzed the mineral composition of salt rock and insoluble mudstones by using XRD and SEM methods. Then, experimental studies were carried out considering both clay swelling and physical packing. At last, the zeta potential tests were conducted to reveal the swelling mechanisms of the bottom mudstones. Results show that the volumetric expansion of mudstones is made up of three parts: clay swelling, particle surface bound water volume, and pore space free water volume increase. Because the content of expansive clay in the bottom mudstones is less than 2%, and the high salinity brine in the cavern has excellent clay stability performance, clay swelling is not the main contributor to the volumetric expansion of the bottom mudstones. Measurement results show that the surface of the mudstones is negatively charged after hydration. Electrostatic repulsion can increase the spacing between small rock particles and creates approximately 47.6% of the pore space, which is the main factor in the volumetric expansion of mudstones. This study provides a theoretical basis for the mining solution and capacity enlargement during the construction of bedded salt cavern gas storage in China.

We report the large‐scale synthesis of photoluminescent single‐chain nanoparticles (SCNPs) by electrostatic‐mediated intramolecular crosslinking in a concentrated solution of 40 mg mL−1 by continuous addition of the free radical initiator. Poly(vinyl benzyl chloride) was charged by quaternization with vinyl‐imidazolium for the intramolecular crosslinking by using 2,2‐dimethoxy‐2‐phenylacetophenone (DMAP) as the radical initiator. Under the electrostatic repulsion thus interchain isolation, the intrachain crosslinking experiences the transition from coil through pearl‐necklace to globular state. The SCNPs demonstrate strong photoluminescence in the visible range when the non‐emissive units are confined thereby. Composition and microstructure of the SCNPs are tunable. The photoluminescent tadpole‐like Janus SCNP can be used to selectively illuminate interfacial membranes while stabilizing the emulsions. [ABSTRACT FROM AUTHOR]

Summary: This study was aimed at improving the emulsifying property and physical stability of pea protein isolate (PPI) stabilised emulsions at acidic conditions by complexation with dextran sulphate (DS). Soluble and insoluble complexes with different charge and particle size were formed depending on the phase separation behaviour. The surface adsorption of PPI became slower after complexation with DS, but the percentage of adsorbed proteins at the oil–water interface was not affected. The formation of PPI–DS soluble complexes at high content of DS (≥0.4%) significantly improved the negative net charges of PPI, prevented the aggregation of protein, which further improved the emulsifying property of PPI at acidic conditions through the strong electrostatic repulsion and steric hindrance effects. Insoluble complexes with relatively weak net charge and large particles were formed at low DS content (≤0.2%), resulting in the bridging flocculation of oil droplets at pH 5 and 4. Thus, the emulsifying ability of PPI under acidic conditions could be significantly improved by formation of soluble complexes with DS. [ABSTRACT FROM AUTHOR]

Stimuli‐sensitive polymers are a class of macromolecular system with "intelligent" behavior. Herein, a copolymer of poly (acrylamide‐co‐2‐acrylamido‐dodecyl sulfonate), which has salt‐sensitive and thermosensitive properties, is synthesized via precipitation polymerization. Its aqueous solution exhibits a clear sol state, while a gel is obtained via salt‐induction by addition a certain amount of NaCl. More interestingly, the gel can transform into clear sol again upon heating, which exhibits a phase transition of upper critical solution temperature in NaCl solution. The dual responsive behaviors of copolymer solutions are studied via rheological measurements. Then fluorescence spectrum, zeta potential test, and dynamic light scattering are employed to investigate molecular interaction in aqueous solution under varying conditions. It is found that dual responsive behaviors are caused by electrostatic interaction and hydrophobic association. At last, oily emulsion wastewater treatment indicates that this polymer shows characteristics of "smart flocculant" and has potential application prospect. [ABSTRACT FROM AUTHOR]

Guanine radical cation (G•+) is a key intermediate in many oxidative processes occurring in nucleic acids. Here, by combining mixed Quantum Mechanical/Molecular Mechanics calculations and Molecular Dynamics (MD) simulations, we study how the structural behaviour of a tract GGG(TTAGGG) 3 (hereafter Tel21) of the human telomeric sequence, folded in an antiparallel quadruple helix, changes when one of the G bases is ionized to G•+ (Tel21+). Once assessed that the electron-hole is localized on a single G, we perform MD simulations of twelve Tel21+ systems, differing in the position of G•+ in the sequence. When G•+ is located in the tetrad adjacent to the diagonal loop, we observe substantial structural rearrangements, which can decrease the electrostatic repulsion with the inner Na+ ions and increase the solvent exposed surface of G•+. Analysis of solvation patterns of G•+ provides new insights on the main reactions of G•+, i.e. the deprotonation at two different sites and hydration at the C8 atom, the first steps of the processes producing 8oxo-Guanine. We suggest the main structural determinants of the relative reactivity of each position and our conclusions, consistent with the available experimental trends, can help rationalizing the reactivity of other G-quadruplex topologies. • The formation of Guanine radical cations (G+) is a key step in DNA oxidative reactions. • We show how G+ changes the structure of human telomeric G-quadruplex (G4). • For some positions G+ causes a substantial structural rearrangement. • Major driving forces for structural shifts are G interactions with ions and solvent. • The presented structures are consistent with available experimental data on G4 oxidative damage. [ABSTRACT FROM AUTHOR]

Rechargeable aqueous Zn batteries are potential for large‐scale electrochemical energy storage due to their low cost and high security. However, Zn metal anode suffers from the dendritic growth and interfacial hydrogen evolution reaction (HER), resulting in the deterioration of electrode/battery performance. Here we propose that both dendrites and HER are related to the water participated Zn2+ solvation structure‐Zn(H2O)62+ and thus can be resolved by transforming Zn(H2O)62+ to an anion‐type water‐free solvation structure‐ZnCl42−, which is achieved in traditional ZnSO4 aqueous electrolyte after adding chloride salt with a bulky cation (1‐ethyl‐3‐methylimidazolium chloride). The elimination of cation‐water interaction suppresses HER, while the electrostatic repulsion between Zn tips and the anion solvation structure inhibits dendrite formation. As a result, the electrolyte shows uniform Zn deposition with an average Zn plating/stripping Coulombic efficiency of ≈99.9 %, enabling a capacity retention of 78.8 % after 300 cycles in anode‐free Zn batteries with pre‐zincificated polyaniline as the cathode. This work provides a novel electrolyte design strategy to prevent HER and realize long‐lifespan metal anode. [ABSTRACT FROM AUTHOR]

Lithium–sulfur batteries are deemed to have the opportunity to replace lithium‐ion batteries because of their high energy density. Nonetheless, the shuttling of soluble long‐chain polysulfides severely deteriorates the cyclic performances of the batteries. Herein, an encapsulated sulfur electrode to tackle the shuttle effect is designed. This high‐performance electrode is fabricated by encapsulating the active sulfur inside a sealing configuration composed of lithiated Nafion (Li‐Nafion), carbon black (BP2000), and a binder of polytetrafluoroethylene. The dense surface of the encapsulated configuration can physically obstruct the mobility of soluble polysulfides. Meanwhile, the sulfonic acid groups fixed on the Li‐Nafion backbone provide a robust electrostatic repulsion to inhibit the negatively charged polysulfides from migrating into the electrolyte. Therefore, the encapsulated sulfur electrode delivers 522.6 mAh g−1 at the 600th cycle with a retention of 80.36%, exhibiting a more competitive cyclic stability than the pristine sulfur electrode. [ABSTRACT FROM AUTHOR]

The stability and aggregation of NIST monoclonal antibody (NISTmAb) were investigated by hydrogen/deuterium exchange mass spectrometry (HDX‐MS), differential scanning calorimetry (DSC), and nano‐differential scanning fluorimetry (nanoDSF). NISTmAb was prepared in eight formulations at four different pHs (pH 5, 6, 7, and 8) in the presence and absence of 150 mM NaCl and analyzed by the three methods. The HDX‐MS results showed that NISTmAb is more conformationally stable at a pH near its isoelectric point (pI) in the presence of NaCl than a pH far from its pI in the absence of NaCl. The stabilization effects were global and not localized. The midpoint temperature of protein thermal unfolding transition results also showed the CH2 domain of the protein is more conformationally stable at a pH near its pI. On the other hand, the onset of aggregation temperature results showed that NISTmAb is less prone to aggregate at a pH far from its pI, particularly in the absence of NaCl. These seemingly contradicting results, higher conformational stability yet higher aggregation propensity near the pI than far away from the pI, can be explained by intramolecular and intermolecular electrostatic repulsion using Lumry‐Eyring model, which separates folding/unfolding equilibrium and aggregation event. The further a pH from the pI, the higher the net charge of the protein. The higher net charge leads to greater intramolecular and intermolecular electrostatic repulsions. The greater intramolecular electrostatic repulsion destabilizes the protein and the greater intermolecular electrostatic repulsion prevents aggregation of the protein molecules at pH far from the pI. [ABSTRACT FROM AUTHOR]

[Display omitted] • Two electro-MBRs with anodic/cathodic cleaning were constructed to mitigate membrane fouling efficiently. • The membrane module was never replaced during 60 d operation in electro-MBRs with anodic/cathodic cleaning. • Gas scouring of the cake layer owing to electrolysis plays a major role in mitigating membrane fouling. • Increased Cleaning bias and time were beneficial to membrane flux recovery. Low-maintenance membrane cleaning is essential for the stable operation of membrane bioreactors. This work proposes an in-situ electrical-cleaning method using an electro-MBR. When the applied bias was transiently increased, the membrane flux recovered rapidly because of the scouring effect from gas evolution reactions. The exfoliation of the cake layer induced by gas scouring played a major role in mitigating membrane fouling, recovering the transmembrane pressure (TMP) by 88.6 % under optimal conditions. Membrane modules did not require replacement during the operation period due to the efficacy of electrical cleaning, with the TMP varying between 37.5 % and 62.5 % of the ultimate pressure requiring change of the membrane modules. Despite the increase in power consumption of 0.66 Wh·m−3 due to the additional applied bias, there was no need for chemical additives or manual maintenance. Therefore, the electrical cleaning method enhanced the service life and reduced the maintenance costs of the electro-MBR. [ABSTRACT FROM AUTHOR]

Nanobubbles and surfactants are two special cases with extraordinary properties that have significantly attracted researchers interest in the recent years. In this paper, the relation between them is investigated in terms of interfacial phenomena. It is shown that the observed decrease in the surface tension of anionic surfactant aqueous solutions in the presence of bulk NBs, can be attributed to the electrostatic repulsive interaction between the electro-steric stabilized NBs and the anionic surfactant molecules. This complex system of anionic surfactant-nanobubble functions as a novel surface-modifying agent that can potentially be used in industries like oil & gas industry, food industry, cosmetic industry, wastewater treatment, surface cleaning and medical applications where surfactant technology is extensively applied. [ABSTRACT FROM AUTHOR]

DOTA (1,4,7,10‐tetraazacyclododecane‐1,4,7,10‐tetraacetic acid)‐based chelates that give only a single isomer in solution when complexed with lanthanide (Ln3+) ions is of value for studying protein dynamics and interactions via NMR. Herein, we have investigated the geometries, energetics, and electrostatic potentials of Lu complexed with DOTA (1), ring methylated M4DOTA (2), and arm methylated R‐DOTMA (3) and S‐DOTMA (4), as well as, both ring and arm methylated 4S‐4S‐M4DOTMA (5) and 4S‐4R‐M4DOTMA (6) at the level of M06‐L/6‐31+G(d)‐SDD, to elucidate the origin of the isomer stability. These analyses indicate that the electrostatic repulsion between the arm methyl and the neighboring carboxylate significantly destabilizes the square antiprism (SAP) isomer of Lu‐5 and the twisted square antiprism (TSAP) isomer of Lu‐6, while the steric repulsion between the ring and arm methyl groups attenuates the stability of both TSAP of Lu‐5 and SAP of Lu‐6. To rationalize the variable temperature proton NMR spectra, the energy barriers for the inter‐conversion in Lu‐5 and Lu‐6 via arm rotation were also calculated. The modulation of the stability and rigidity of Ln complexes via a modification of DOTA is also discussed. Our investigation will aid to design better chelates for the Ln3+ ions for its use in molecular medicine. [ABSTRACT FROM AUTHOR]

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Directed self-assembly uses different stimuli to initiate and control the interaction between nanocrystals. Protonation at reduced pH represents a convenient stimulus for initiating self-assembly. Prior work has focused on protonation-induced hydrogen bonding between peptide or amino acid functionalized nanocrystals for reversible cycling between dispersed and aggregated states. Here, we discuss a fundamentally different approach, in which changes in pH modify the nonspecific interparticle interaction between Au nanorods conjugated with single-stranded (ss) DNA. While electrostatic repulsion stabilizes dispersed suspensions at neutral pH, protonation in acidic solution modifies the DNA corona, turning the interaction between the rods attractive and triggering their self-assembly. Analysis of in-situ electron microscopy of ssDNA-Au nanorods in solution is consistent with a van der Waals attraction of charge-neutral monomers at acidic pH. The results demonstrate ssDNA-conjugated anisotropic nanostructures as versatile building blocks with stimuli-programmable interactions for on-demand self-assembly. [ABSTRACT FROM AUTHOR]

Copyright of Shipin Kexue/ Food Science is the property of Food Science 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.)

This study investigates the applicability of six transition metal dichalcogenides to efficient therapeutic drug monitoring of ten antiepileptic drugs using laser desorption/ionization-mass spectrometry. We found that molybdenum ditelluride and tungsten ditelluride are suitable for the sensitive quantification of therapeutic drugs. The contribution of tellurium to the enhanced efficiency of laser desorption ionization was validated through theoretical calculations utilizing an integrated model that incorporates transition-metal dichalcogenides and antiepileptic drugs. The results of our theoretical calculations suggest that the relatively low surface electron density for the tellurium-containing transition metal dichalcogenides induces stronger Coulombic interactions, which results in enhanced laser desorption and ionization efficiency. To demonstrate applicability, up to 120 patient samples were analyzed to determine drug concentrations, and the results were compared with those of immunoassay and liquid chromatography-tandem mass spectrometry. Agreements among these methods were statistically evaluated using the Passing-Bablok regression and Bland-Altman analysis. Furthermore, our method has been shown to be applicable to the simultaneous detection and multiplexed quantification of antiepileptic drugs.