Anionic Groups Research Articles

Constructing Metal(II)-Sulfate Site Catalysts toward Low Overpotential Carbon Dioxide Electroreduction to Fuel Chemicals.

Precise regulation of the active site structure is an important means to enhance the activity and selectivity of catalysts in CO2 electroreduction. Here, we creatively introduce anionic groups, which can not only stabilize metal sites with strong coordination ability but also have rich interactions with protons at active sites to modify the electronic structure and proton transfer process of catalysts. This strategy helps to convert CO2 into fuel chemicals at low overpotentials. As a typical example, a composite catalyst, CuO/Cu-NSO4/CN, with highly dispersed Cu(II)-SO4 sites has been reported, in which CO2 electroreduction to formate occurs at a low overpotential with a high Faradaic efficiency (-0.5 V vs. RHE, FEformate=87.4 %). Pure HCOOH is produced with an energy conversion efficiency of 44.3 % at a cell voltage of 2.8 V. Theoretical modeling demonstrates that sulfate promotes CO2 transformation into a carboxyl intermediate followed by HCOOH generation, whose mechanism is significantly different from that of the traditional process via a formate intermediate for HCOOH production.

[C(NH2)3]10(MoO3)10(PO4)2(HPO4)2·5H2O: Synergy effect of multiple functional units results in significant birefringence

In recent years, research has demonstrated the efficacy of synthesizing linear and nonlinear optical materials with exceptional properties through the synergy interaction of large anisotropic groups. Nevertheless, there is a paucity of studies focusing on the concurrent incorporation of planar π-conjugated groups and distorted d0 transiton metal octahedra into phosphates system. A novel organic–inorganic hybrid phosphate, namely, [C(NH2)3]10(MoO3)10(PO4)2(HPO4)2·5H2O (GMPO), which was synthesized using hydrothermal approach and presented in this study. GMPO exhibits a three-dimensional network structure composed of [(MoO3)5(PO4) (HPO4)]5− anionic group, water molecules, and guanidine cations interconnected through hydrogen bonding. GMPO possesses a notable birefringence of 0.158@550 nm with a band gap of 3.43 eV, suggesting its possible use as the UV birefringent material. Theoretical calculation suggests that the significant birefringence of GMPO is primarily attributed to the synergy effect of multifarious functional units contained in title compound.

Self-assembly of choline-based surface-active ionic liquids and concentration-dependent enhancement in the enzymatic activity of cellulase in aqueous medium.

The micellization of choline-based anionic surface-active ionic liquids (SAILs) having lauroyl sarcosinate [Sar]-, dodecylsulfate [DS]-, and deoxycholate [Doc]- as counter-ions was investigated in an aqueous medium. Density functional theory (DFT) was employed to investigate the net interactional energy (Enet), extent of non-covalent interactions, and band gap of the choline-based SAILs. The critical micelle concentration (cmc) along with various parameters related to the surface adsorption, counter-ion binding (β), and polarity of the cores of the micelles were deduced employing surface tension measurements, conductometric titrations and fluorescence spectroscopy, respectively. A dynamic light scattering (DLS) system equipped with zeta-potential measurement set-up and small-angle neutron scattering (SANS) were used to predict the size, zeta-potential, and morphology, respectively, of the formed micelles. Thermodynamic parameters such as standard Gibb's free energy and standard enthalpy change of micellization were calculated using isothermal titration calorimetry (ITC). Upon comparing with sodium salt analogues, it was established that the micellization was predominantly governed by the extent of hydration of [Cho]+, the head groups of the respective anions, and the degree of counter-ion binding (β). Considering the concentration dependence of the enzyme-SAIL interactions, aqueous solutions of the synthesized SAILs at two different concentrations (below and above the cmc) were utilized as the medium for testing the enzymatic activity of cellulase. The activity of cellulase was found to be ∼7- to ∼13-fold higher compared to that observed in buffers in monomeric solutions of the SAILs and followed the order: [Cho][Sar] > [Cho][DS] > [Cho][Doc]. In the micellar solution, a ∼4- to 5-fold increase in enzymatic activity was observed.

Benzothiadiazole-based water-soluble macrocycle: Synthesis, aggregation-induced emission and selective detection of spermine

Reported here is the synthesis of a new macrocycle bearing anionic carboxylate groups with water-soluble aggregation-induced emission (AIE). The water-soluble macrocycle without typical AIE luminogens is constructed based on the building block of benzothiadiazole. It exhibits a remarkable AIE effect. This water-soluble macrocycle can selectively bind different types of biogenic amines in aqueous media with the tightest binding towards spermine. The fluorescence enhancement induced by supramolecular encapsulation is used to detect spermine.

Homoatomic Polychalcogenide Nonlinear Optical Anionic Groups with Ultra-Large Optical Anisotropy.

Functional assembly of nonlinear optical (NLO) motifs with a large optical anisotropy is vital to the development of advanced NLO and birefringent materials. In this work, we highlight that, in addition to heteroatomic NLO motifs, homoatomic anionic clusters formed by aggregated anions (S, Se, Te) exhibit diverse chain-, ring-, and cage-like chemical structures as well as one-, two-, and three-dimensional motif alignments. The rich structural chemistry enables homoatomic polychalcogenides (HAPCs) to exhibit asymmetric structural features and anisotropic optical properties, with great potential for NLO and birefringent performance. Focusing on totally 55 binary HAPCs A2Qn (n = 2, 3, 4, 5; A = Na, K, Rb, Cs; Q = S, Se, Te) and their ternary analogues, we employ the state-of-the-art first-principles approach to systematically investigate the modulation evolution of their NLO and birefringent properties. Remarkably, Rb2Te3 and Na2TeSe2 exhibit rarely colossal birefringence (>1.0@10 μm) and NLO effects (>20 × AgGaS2), much larger than conventional NLO chalcogenides. Na2Te3 presents the largest birefringence to date (∼3.48@1, 2.72@2, 2.34@10 μm), indicating the unique structural superiority of HAPC in terms of ultra-large birefringence. By mining the intrinsic mechanism, the HAPC anionic groups are identified as novel mid-infrared NLO "material genes", furnishing unique NLO and birefringent performance for the design of novel optoelectronic materials.

(C4H6N3O)(HSO4): A Cytosinium Bisulfate with Large Birefringence and Moderate Second Harmonic Generation Effect Produced via Combining a Promising Planar Nonlinear Optical-Active Motif with a Tetrahedral Group.

Investigating novel nonlinear optical (NLO) active units serves as a valuable method for broadening the research landscape of NLO materials. This study showcases the potential of the cytosinium cation (C4H6N3O)+ as a novel NLO-active motif through theoretical calculations. The title compound exhibited a wide band gap of 3.85 eV, along with a moderate second harmonic generation (SHG) response of 1.65 times that of KH2PO4 (KDP) and significant birefringence of 0.47. Its exceptional optical properties are primarily attributed to the synergy interaction between cations and anionic groups in the asymmetric unit.

Rheology of Suspensions of TEMPO-Oxidised and Cationic Cellulose Nanofibrils-The Effect of Chemical Pre-Treatment.

Cellulose nanofibrils (CNFs) are particles with a high aspect ratio. Typically, chemically pre-treated CNFs (containing anionic or cationic charged groups) consist of long fibrils (up to 2 μm) with very low thickness (less than 10 nm). Derived from their high aspect ratio, CNFs form strong hydrogels with high elasticity at low concentrations. Thus, CNF suspensions appear as an interesting rheology modifier to be applied in cosmetics, paints, foods, and as a mineral suspending agent, among other applications. The high viscosity results from the strong 3D fibril network, which is related to the good fibrillation of the material, allowing the nanofibrils to overlap. The overlap concentration (c*) was found to vary from ca. 0.13 to ca. 0.60 wt.% depending on the type and intensity of the pre-treatment applied during the preparation of the CNFs. The results confirm the higher tendency for the fibres treated with (3-chloro-2-hydroxypropyl) trimethylammonium chloride (CHPTAC) and 2,2,6,6-tetramethylpiperidine 1-oxyl (TEMPO) to form a 3D network, resulting in the lowest c*. For the TEMPO-oxidised CNF suspensions, it was also found that aggregation is improved at acidic pH conditions due to lower charge repulsion among fibrils, leading to an increase in the suspension viscosity as well as higher apparent yield stresses. TEMPO CNF suspensions with a low content of carboxylic groups tend to precipitate at moderately acidic pH values.

Two Short-Wave UV Beryllium Selenites Exhibiting Diverse Optical Properties Stemming from Functional Group Arrangements.

The arrangement of functional groups exerts a crucial role in determining the characteristics of compounds. In this study, we synthesized two novel short-wave ultraviolet (UV) nonlinear optical (NLO) crystals: KBe2(SeO3)2(OH)·H2O and K2Be(SeO3)2. Interestingly, the two compounds show the same SeO3 triangular pyramids and K-O polyhedra. However, the two compounds exhibit distinct beryllium-oxygen anion groups: BeO3(OH) for KBe2(SeO3)2(OH)·H2O and BeO4 for K2Be(SeO3)2. This results in the SeO3 groups within the structure having different orientations, ultimately leading to the two compounds exhibiting completely different optical properties. KBe2(SeO3)2(OH)·H2O displays a large second harmonic generation (SHG) effect equivalent to 2× KH2PO4 (KDP), coupled with a large birefringence of 0.078 at 546 nm. In contrast, the SHG effect and birefringence of K2Be(SeO3)2 are only 0.33× that of KDP and 0.024 at 546 nm, respectively. Structural analyses and theoretical calculations indicate that these pronounced differences in optical properties stem from variations in the arrangement of the SeO3 functional groups. This study not only sheds light on the correlation between crystal structure and optical behavior but also presents a hopeful avenue for the advancement of materials in the short-wave UV spectrum.

Effects of polymers with different anionic groups in drilling fluids and their properties of temperature and salt resistance

To investigate the performance characteristics of polymers with different functional groups in drilling fluid matrix (clay suspension), two anionic acrylamide-based polymers with molecular weights of approximately 1 million and the same monomer ratio, namelypoly(acrylamidoacrylate) (P(AM-AA)) and poly(acrylamidoallyl sulfonate) (P(AM-SAS)), were synthesized using a water-dispersion polymerization method. Using polyacrylamide (PAM) with the same molecular weight as a reference, thermogravimetric analysis, scanning electron microscopy, zeta potential analysis, particle size distribution test, and drilling fluid performance test were conducted to assess the thermal stability of the polymers as well as the microstructures and properties of the corresponding drilling fluids. The results demonstrated that both P(AM-AA) and P(AM-SAS) exhibited significant intercalation effects on clay in drilling fluids, leading to an increase in the zeta potential of clay particles and the formation of a bimodal particle size distribution. These polymers also effectively reduced filtration loss and altered the rheological properties of the drilling fluids. However, the influence of polymers on temperature and salt resistance did not conform to the traditional understanding that sulfonic acid groups offer better hydration and salt resistance compared to carboxyl groups. The performance characteristics of the polymers were influenced not only by their own structure, but also by the clay content, salt content, temperature in the drilling fluids. Specifically, in freshwater drilling fluids, P(AM-AA) exhibited a slightly lower but comparable reduction in filter loss compared to P(AM-SAS). Furthermore, P(AM-AA) was less affected by clay content than P(AM-SAS) and showed stronger filter loss reduction in brine drilling fluids with NaCl content ≤3 wt%, while exhibiting less sensitivity to variations in NaCl content. Conversely, P(AM-SAS) demonstrated stronger filter loss reduction and lower sensitivity to NaCl content in brine drilling fluids with NaCl content >3 wt%. The influence of high-temperature aging (120–180 °C) on filter loss reduction function was similar for both P(AM-AA) and P(AM-SAS). The rheology of the formulated drilling fluid was less sensitive to clay content when utilizing P(AM-AA) compared to P(AM-SAS). Moreover, the apparent viscosity of the drilling fluid with P(AM-AA) was more impacted by NaCl when the NaCl content was below 5 wt%, showing greater sensitivity than P(AM-SAS). However, there was no significant difference in rheological stability between P(AM-AA) and P(AM-SAS) under high-temperature aging conditions.

Investigation of anionic group characteristics of PCEs on the behaviour of fly ash cementitious systems

The compatibility of polycarboxylate-based water-reducing admixtures (PCEs) having different carboxylate, phosphate and sulfonate anionic groups with paste and mortar mixtures containing fly ash (FA) was investigated. It was found that, with an increase in the FA content of the mixtures, the PCE requirement for the target flow decreased and the consistency retention performance was improved due to the decrease in the amount of hydrated cement. An improvement in rheological parameters was observed with an increase in FA content from 15% to 30%. However, increasing the FA replacement level beyond 30% caused stability problems in the mixtures. This problem was eliminated with the addition of PCE. In the paste and mortar mixtures, regardless of the FA substitution ratio, the best performance was obtained with PCEs containing 7% and 5% phosphate and sulfonate, respectively. The most suitable FA replacement ratio in terms of rheological parameters and 28-day compressive strength was 30% and 15%, respectively. It was observed that the PCE anionic group content did not have any significant effect for all FA substitution ratios.

Surface ligand-regulated renal clearance of MRI/SPECT dual-modality nanoprobes for tumor imaging

BackgroundThe general sluggish clearance kinetics of functional inorganic nanoparticles tend to raise potential biosafety concerns for in vivo applications. Renal clearance is a possible elimination pathway for functional inorganic nanoparticles delivered through intravenous injection, but largely depending on the surface physical chemical properties of a given particle apart from its size and shape.ResultsIn this study, three small-molecule ligands that bear a diphosphonate (DP) group, but different terminal groups on the other side, i.e., anionic, cationic, and zwitterionic groups, were synthesized and used to modify ultrasmall Fe3O4 nanoparticles for evaluating the surface structure-dependent renal clearance behaviors. Systematic studies suggested that the variation of the surface ligands did not significantly increase the hydrodynamic diameter of ultrasmall Fe3O4 nanoparticles, nor influence their magnetic resonance imaging (MRI) contrast enhancement effects. Among the three particle samples, Fe3O4 nanoparticle coated with zwitterionic ligands, i.e., Fe3O4@DMSA, exhibited optimal renal clearance efficiency and reduced reticuloendothelial uptake. Therefore, this sample was further labeled with 99mTc through the DP moieties to achieve a renal-clearable MRI/single-photon emission computed tomography (SPECT) dual-modality imaging nanoprobe. The resulting nanoprobe showed satisfactory imaging capacities in a 4T1 xenograft tumor mouse model. Furthermore, the biocompatibility of Fe3O4@DMSA was evaluated both in vitro and in vivo through safety assessment experiments.ConclusionsWe believe that the current investigations offer a simple and effective strategy for constructing renal-clearable nanoparticles for precise disease diagnosis.Graphical

In-Situ Grown Nanohydroxyapatite on Graphene Oxide Nanoscrolls for Modulated Physicochemical Properties of Poly (Caprolactone) Composites

Polymer composites with exceptional bioactivity and controlled in vitro degradation are crucial in tissue engineering. A promising approach involves combining graphene oxide nanoscrolls (GONSs) and nanohydroxyapatite (nHA) with polycaprolactone (PCL). The synergy of these components enables the mineralization of nHA within GONSs through a two-step process: first, oxygen-containing anionic groups in the GONSs anchor Ca2+ ions, followed by the formation of dispersed nHA through chelation with CaHPO42− via electrovalent bonding. A thermal analysis of the scaffolds’ morphology and microstructure was conducted via DSC and SEM imaging. Its enhanced physical properties are attributed to interactions between PCL and nHA–GONSs, as confirmed by an FTIR analysis showing strong interfacial bonding. Enzymatic degradation studies demonstrated reduced weight loss in PCL–nHA–GONS composites over 21 days, highlighting GONSs’ role in enhancing dimensional stability and reinforcement. An EDS analysis post-degradation revealed increased Ca2+ deposition on scaffolds with nHA–GONSs, indicating improved biopolymer–bioceramic interaction facilitated by the GONSs’ scrolled structure. This research offers a straightforward yet effective method for functionalizing GONSs with biologically beneficial nHA, potentially advancing graphene-based biomaterial development.

Achieving High-Performance Lithium-Sulfur Batteries by Modulating Li+ Desolvation Barrier with Liquid Crystal Polymers.

Lithium-sulfur (Li-S) batteries offer high theoretical capacity but are hindered by poor rate capability and cycling stability due to sluggish Li2S precipitation kinetics. Here a sulfonate-group-rich liquid crystal polymer (poly-2,2'-disulfonyl-4,4'-benzidine terephthalamide, PBDT) is designed and fabricated to accelerate Li2S precipitation by promoting the desolvation of Li+ from electrolyte. PBDT-modified separators are employed to assemble Li-S batteries, which deliver a remarkable rate capacity (761 mAh g-1 at 4 C) and cycling stability (500 cycles with an average decay rate of 0.088% per cycle at 0.5 C). A PBDT-based pouch cell even delivers an exceptional capacity of ≈1400 mAh g-1 and an areal capacity of ≈11 mAh cm-2 under lean-electrolyte and high-sulfur-loading condition, demonstrating promise for practical applications. Results of Raman spectra, molecular dynamic (MD) and density functional theory (DFT) calculations reveal that the abundant anionic sulfonate groups of PBDT aid in Li+ desolvation by attenuating Li+-solvent interactions and lowering the desolvation energy barrier. Plus, the polysulfide adsorption/catalysis is also excluded via electrostatic repulsion. This work elucidates the critical impact of Li+ desolvation on Li-S batteries and provides a new design direction for advanced Li-S batteries.

High‐Voltage Off‐Stoichiometric Vanadium‐Based Pyrophosphate Na6.51V3.16(P2O7)4 for Rechargeable Sodium‐Ion Batteries

AbstractThe accessibility of high‐performance sodium‐ion batteries (SIBs) hinges upon cathodes with high voltage and large reversible capacity. Among the contenders, vanadium‐based polyanionic compound with strong inductive effect from anionic group and multiple accessible oxidation states of vanadium emerged as a formidable competitor, however, only limited candidates in this field were reported so far. This manuscript delineated the rational synthesis of a novel off‐stoichiometric pyrophosphate Na6.51V3.16(P2O7)4. It delivers a specific capacity of 102 mAh g−1 at the current density of 20 mA g−1, as well as a high discharge median voltage of 3.87 V vs. Na+/Na, rendering it a rare sodium‐ion storage host with multi‐redox couples (V5+/4+/3+/2+). The experimental approach to phase adjustment in this article offers guidelines for exploiting of new cathode materials for high‐performance SIBs.

Important Factors Affecting Induction of Cell Death, Oxidative Stress and DNA Damage by Nano- and Microplastic Particles In Vitro.

We have described the influence of selected factors that increase the toxicity of nanoplastics (NPs) and microplastics (MPs) with regard to cell viability, various types of cell death, reactive oxygen species (ROS) induction, and genotoxicity. These factors include plastic particle size (NPs/MPs), zeta potential, exposure time, concentration, functionalization, and the influence of environmental factors and cell type. Studies have unequivocally shown that smaller plastic particles are more cytotoxic, penetrate cells more easily, increase ROS formation, and induce oxidative damage to proteins, lipids, and DNA. The toxic effects also increase with concentration and incubation time. NPs with positive zeta potential are also more toxic than those with a negative zeta potential because the cells are negatively charged, inducing stronger interactions. The deleterious effects of NPs and MPs are increased by functionalization with anionic or carboxyl groups, due to greater interaction with cell membrane components. Cationic NPs/MPs are particularly toxic due to their greater cellular uptake and/or their effects on cells and lysosomal membranes. The effects of polystyrene (PS) vary from one cell type to another, and normal cells are more sensitive to NPs than cancerous ones. The toxicity of NPs/MPs can be enhanced by environmental factors, including UV radiation, as they cause the particles to shrink and change their shape, which is a particularly important consideration when working with environmentally-changed NPs/MPs. In summary, the cytotoxicity, oxidative properties, and genotoxicity of plastic particles depends on their concentration, duration of action, and cell type. Also, NPs/MPs with a smaller diameter and positive zeta potential, and those exposed to UV and functionalized with amino groups, demonstrate higher toxicity than larger, non-functionalized and environmentally-unchanged particles with a negative zeta potential.

Synthesis, Crystal Growth, Structural Characterization, Supramolecular Chemistry, and Theoretical Calculations of Methylenium Salts of Benzenesulfonates

AbstractThe current investigation describes the synthesis of four novel methylene blue (MB) salts of benzene sulfonate derivatives, featuring bulky anionic groups. The process involves treating chloride salt of MB with sodium salts of 4‐aminobenzene sulfonate, 4‐styrenebenzene sulfonate, 3,7‐naphthalene disulfonate, and anthraquinone‐1,5‐naphthalene disulfonate to substitute the chloride ion with benzoate sulfonate anion in MB‐chloride. The synthesis includes quaternizing MB‐chloride with the corresponding benzene sulfonate in minimal aqueous solvent to promote precipitation. The resultant precipitates were subsequently dissolved in an appropriate solvent to enable the crystallization of the ultimate product. The dissolution occurs either at ambient temperature or with heat. The crystals of the resultant salts were characterized using various analytical techniques like UV‐visible, and FT‐IR spectroscopy, TGA, single crystal X‐ray diffraction and powder X‐ray diffraction analysis. The UV‐visible spectroscopic results, frontier molecular orbital, density of states, molecular electrostatic potentials, and HOMO‐LUMO energy gaps were estimated by DFT. Structural analysis revealed that supramolecular structure of compounds achieved stabilization through electrostatic interactions, a diverse range of both conventional and non‐conventional hydrogen bonds, π–π stacking interactions, and other short‐range interactions. The investigation delves into intricate details and offers a thorough discussion of the fundamental principles that contribute to the formation and stabilization of supramolecular structures.

A synergistic polyelectrolytes-Zr-MOF hydrated construction graphene oxide nanofiltration with enhanced dye wastewater remediation

In recent years, developing an efficient nanofiltration membrane had been a thorny challenge for dye/salt wastewater purification. In this study, a novel graphene oxide-based nanofiltration membrane (GO/UiO@S-GO-8) was constructed by intercalating the synergistic polyelectrolytes-Zr-MOF hydrated construction (UiO@S-GO) into GO nanosheets. Here, combining the hydrophilic high-density anionic sulfonic groups (SO3-) with cationic amino groups (-NH2), GO-based nanofiltration membrane demonstrated outstanding separation ability, anti-pollution performance and structure stability. Compared to pure GO membrane, benefiting by effective expansion of graphene layer spacing from intercalation effect of UiO@S-GO, the water permeance of GO/UiO@S-GO-8 membrane increased to 8 times (about 66.3 ± 1.5 L m−2 h−1 bar−1). Importantly, the permeances of various dyes wastewater also reached up to 65.1 ± 1.8 L m−2 h−1 bar−1 at the high removal rate (exceeding 99.4%). Furthermore, strong hydratability of polyelectrolytes and hard porous crystal constructed the robust anti-fouling micro/nano rough structures onto the membrane surface, which made flux recovery rate (FRR) of GO/UiO@S-GO-8 enhanced to 96.7 ± 1.3%. Remarkably, the salt-resistant behavior of the polyelectrolytes and porous MOF could maintain the stability of the membrane filtration channels, the GO/UiO@S-GO-8 membrane could realize efficient removal rate of dyes (over 98%) faced the complex dye wastewater with different salt concentrations. Meanwhile, the GO/UiO@S-GO-8 membrane also could maintain the high permeance (46.7 ± 1.5 L m−2 h−1 bar−1) as well as excellent removal rate (97.2 ± 1.4%) after 10 cycle experiments. Hence, the GO/UiO@S-GO-8 nanofiltration membrane with Polyelectrolytes-Zr-MOF hydrated construction possessed a broad application inspiration in the purification of high-salt/dye wastewater.

Coupling between cation and anion disorder in β-K2Ca3(CO3)4

Since the development of anionic group theory, the spatial arrangement of anionic groups in optical crystals has been believed to determine their functional, such as nonlinear optical, properties. At the same time, cation substitution, resulting in either the appearance of disordered cation sites in a crystal structure or the emergence of cation-ordered superstructures, has been widely used to control material properties. This work demonstrates the coupling between positional cation disorder and orientational disorder of (CO3)2− anions in the β modification of the recently described K2Ca3(CO3)4 material. In contrast to the α modification [P212121, a = 7.39134 (18), b = 8.8153 (2), c = 16.4803 (4) Å], where the ordered cation sublattice favors the non-centrosymmetric orientationally ordered arrangement of (CO3)2− anionic groups, positional cation disorder in β-K2Ca3(CO3)4 [Pnma, a = 7.5371 (2), b = 16.1777 (5), c = 8.7793 (3) Å] within the cation sublattice of the same topology leads to orientational disorder of (CO3)2− groups and the appearance of an inversion center in the average structure.

Induced Anionic Functional Group Orientation-Assisted Stable Electrode-Electrolyte Interphases for Highly Reversible Zinc Anodes.

Dendrite growth and other side-reaction problems of zinc anodes in aqueous zinc-ion batteries heavily affect their cycling lifespan and Coulombic efficiency, which can be effectively alleviated by the application of polymer-based functional protection layer on the anode. However, the utilization rate of functional groups is difficult to improve without destroying the polymer chain. Here, a simple and well-established strategy is proposed by controlling the orientation of functional groups (─SO3H) to assist the optimization of zinc anodes. Depending on the electrostatic effect, the surface-enriched ─SO3H groups increase the ionic conductivity and homogenize the Zn2+ flux while inhibiting anionic permeation. This approach avoids the destruction of the polymer backbone by over-sulfonation and amplifies the effect of functional groups. Therefore, the modified sulfonated polyether ether ketone (H-SPEEK) coating-optimized zinc anode is capable of longtime stable zinc plating/stripping, and moreover an enhanced cycling steadiness under high current densities is also detected in a series of Zn batteries with different cathode materials, which achieved by the inclusion of H-SPEEK coating without causing any harmful effects on the electrolyte and cathode. This work provides an easy and efficient approach to further optimize the plating/stripping of cations on metal electrodes, and sheds lights on the scale-up of high-performance aqueous zinc-ion battery technology.

Adsorption mechanism of the novel amphoteric dispersant and its effect on structure and properties of hydration products

The novel amphoteric dispersant (NAD) was prepared by free radical polymerization of acrylic acid (AA), vinyl butylpolyoxyethylene ether (VBPE), N,N-dimethyl-methacryloxyethyl-aminopropyl sulfonate (DMAPS) and acrylate sulfated starch (ASS). It is characterized that the introduction of zwitterionic monomer as side groups and modified starch as branch chains. The chemical structure and its effects on the fluidity, strength, durability and microstructure of cement-based composites containing clay were tested. The results indiacted that zwitterions can improve the chelating adsorption capacity and eliminate the influence of chloride ions, while modified starch branch chain can improve the effect of slow coagulation and water retention. NAD has excellent dispersing and mud resistance effect, which makes the interface of cement hydration products clear, regular shape, uniform distribution and compact structure.The dispersion mechanism was proposed and it is think that NAD was mainly adsorbed on the interface of cement particles by zwitterion chelation adsorption and on the interface of the mud particles by anion groups. Meanwhile, the polyoxyethylene and the starch branch chains synergistic to form spatial barrier layer, showing excellent effects on blocking mud water absorption, improving dispersing and regulating hydration products structure. The research results have positive significance for the developing highly effective anti-mud dispersants.