Complex Ions Research Articles

Preparation of electroless deposition of NiTiZr(P) quaternary alloy and their properties

The exceptional super elasticity and corrosion-resistance of Ni-Ti alloys have attracted a lot of attention and interest lately for a wide range of applications, and complex alloy components could be prepared effectively by different preparation techniques. Ni(P), Ni-Ti(P), Ni-Zr(P), and Ni-Ti -Zr(P) binary, ternary, and quaternary alloys were coated on mild steel by electroless deposition which is a method of plating metallic films on a substrate by the reduction of metallic complex ions in solution with the aid of reducing agent from an alkaline bath. The ternary Ni-Ti-Zr(P) alloy is considered to be one of the most promising high-temperature SMAs. SEM, XRD and EDS were used to examine the morphology, phase composition and elemental composition which demonstrate the microstructure of the deposits. The mechanical characteristics of the samples were examined through scratch test and micro hardness analysis and the value increased from 261 HV200 to 405 HV200 and that the coefficient of friction raised significantly from 0.23 to 3.5 owing to the presences of added elements in Ni(P) matrix. Polarization analysis and EIS were tested to evaluate the corrosion properties of coated samples in a non-deaerated 3.5 %wt. (NaCl) solution. The outcomes indicate that as the amount of Ti-Zr elements in the bath raised, the corrosion potential became more positive and the corrosion current density decreased to 14.903 μA/cm2. Furthermore, Ni-Ti-Zr(P) alloy coating strengthens corrosion resistance in comparison to Ni(P).

Metal ion complexes of 2-thioxoimidazolidine-4-one derivatives mixed ligand synthesis, characterization, in-vitro biological activities and in-silico studies

A series of complexes of [Mn (III), Co(II), Cu(II), and Cd(II)] were synthesized with two new 2-thioxoimidazolidin-4-one derivates ligands. These ligands were characterized using an elemental analyzer (CHNS), 1H NMR spectroscopy, FT-IR spectroscopy, and UV–Vis spectroscopy. The synthesized complexes were characterized by magnetic susceptibility measurements, electrical conductance analysis, and atomic absorption spectroscopy. The biological activity of the ligands and complexes were determined against E. coli, B. subtilis, A. niger, and P. chrysogenum. To determine the influence of different metal-ion concentrations on microbial growth, we used molecular docking to evaluate antibacterial activity targeting antimicrobial sites. Our findings indicate that the metal ion complexes exhibited varying degrees of antimicrobial activity, affecting the growth of the tested organisms.

Stability of metal ion complexes with the synthetic phytosiderophore proline-2'-deoxymugineic acid.

Adequate micronutrient concentrations in crops are essential for human health and agricultural productivity. However, 30% of plants growing on cultivated soils worldwide are deficient in iron (Fe). Because of low micronutrient bioavailability, graminaceous plants have evolved to exude small molecules, called phytosiderophores, into the soil environment, which strongly complex and promote uptake of trace elements. The development of a synthetic phytosiderophore, proline-2'-deoxymugeneic acid (PDMA), has been shown to promote Fe uptake in rice plants; however, its binding capabilities with other metals, which may impact the ability to promote the uptake of Fe and other trace nutrient metals commonly found in soils, remain unknown. We conducted spectrophotometric titrations to determine the stability constants (logK) of PDMA complexes with Mn(II), Co(II), Cu(II), Ni(II), and Zn(II). We determined that PDMA complex stability constants correlated with: (1) the hydrolysis constants of metal ions (logKOH) in complexes; (2) the ionic potential of complexed metals; and (3) the corresponding complex stability constants of other mugineic acid type phytosiderophores, as well as the trishydroxamate microbial siderophore DFOB. These correlations demonstrate the potential, and limitations, on our ability to predict the stability of phytosiderophore complexes with metal ions with different physicochemical properties and with potentially different coordination structures.

A review of coordination compounds: structure, stability, and biological significance

Abstract Coordination compounds are molecules that contain one or more metal centers bound to ligands. Ligands can be atoms, ions, or molecules that transfer electrons to the metal. These compounds can be charged or neutral. When charged, neighboring counter-ions help stabilize the complex. The metal ion is located at the center of a complex ion, surrounded by other molecules or ions known as ligands. Ligands can be thought of as covalently bonded to the core ion through coordination. Understanding coordination theory in chemistry provides insight into the geometric shape of complexes and the structure of coordination compounds, which consist of a central atom or molecule connected to surrounding atoms or compounds. Inorganic coordination compounds exhibit different properties and are used in synthesizing organic molecules. The coordination of chemicals is vital for the survival of living organisms. Metal complexes are also essential for various biological processes, with many enzymes, known as metalloenzymes, being composed of metal complexes. These metal complexes occur naturally.

To 200,000 m/z and Beyond: Native Electron Capture Charge Reduction Mass Spectrometry Deconvolves Heterogeneous Signals in Large Biopharmaceutical Analytes.

Great progress has been made in the detection of large biomolecular analytes by native mass spectrometry; however, characterizing highly heterogeneous samples remains challenging due to the presence of many overlapping signals from complex ion distributions. Electron-capture charge reduction (ECCR), in which a protein cation captures free electrons without apparent dissociation, can separate overlapping signals by shifting the ions to lower charge states. The concomitant shift to higher m/z also facilitates the exploration of instrument upper m/z limits if large complexes are used. Here we perform native ECCR on the bacterial chaperonin GroEL and megadalton scale adeno-associated virus (AAV) capsid assemblies on a Q Exactive UHMR mass spectrometer. Charge reduction of AAV8 capsids by up to 90% pushes signals well above 100,000 m/z and enables charge state resolution and mean mass determination of these highly heterogeneous samples, even for capsids loaded with genetic cargo. With minor instrument modifications, the UHMR instrument can detect charge-reduced ion signals beyond 200,000 m/z. This work demonstrates the utility of ECCR for deconvolving heterogeneous signals in native mass spectrometry and presents the highest m/z signals ever recorded on an Orbitrap instrument, opening up the use of Orbitrap native mass spectrometry for heavier analytes than ever before.

Reactivity of [(Cp*CoPh)(Cp*Co)(μ-TePh)(μ-k2-Te,H-TeBH3)] Toward [M(CO)5·THF] (M = Mo and W), CS2, and [Fe2(CO)9

Syntheses and structural elucidation of homo- and heterochalcogen-bridged complexes of cobalt are described. The photolytic reaction of bimetallic hydridoborate species [(Cp*CoPh)(Cp*Co)(μ-TePh)(μ-k2-Te,H-TeBH3)] (1) in the presence of [M(CO)5·THF] (M = Mo and W) afforded unprecedented tellurolate-bridged [(Cp*Co)2(μ-TePh)3]+[TePh{M(CO)5}2]- (M = Mo (2), W (3)) as ionic complexes with the release of BH3. Complex 2 has three bridged-TePh moieties between two Cp*Co fragments in the cation part, whereas the anionic part, [TePh{M(CO)5}2]-, shows a distorted trigonal pyramidal core. In order to synthesize mixed chalcogenate-bridged complexes having both S and Te, we carried out the photolytic reaction of 1 with CS2. Although the objective of generating mixed chalcogen-bridged complex [(Cp*Co)2(μ-TePh)2(μ-S)] was not achieved, the reaction yielded an unusual bimetallic thiotellurite complex [(Cp*Co)2(μ-S3TeS3-κ2S:κ2Te:κ2S')] (4). Complex 4 has two wings, each consisting of three sulfur atoms, that are connected to two Co-atoms and one Te-atom. Further, to synthesize the Fe analogue of 2 and 3, a similar reaction was carried out with [Fe2(CO)9]. However, the reaction led to the formation of the trimetallic complex [Cp*Co(CO)(μ3-Te)2{Fe2(CO)6}] (5). These complexes were characterized by employing different multinuclear NMR, IR spectroscopies, single-crystal X-ray diffraction analyses, and mass spectrometry. Additionally, computational analyses of these chalcogen-bridged neutral and ionic complexes were conducted to offer insight into their bonding.

Pyrite functionalized Black Soldier Fly feces biochar for mine soil quality improvement and heavy metals immobilization

Frequent mining activities have led to an increasing transfer of heavy metals to the soil. Pyrite functionalized Black Soldier Fly feces biochar composite material (BFFS) was synthesized to immobilize Cu and Pb in contaminated mine soil and improve soil quality in our study. Incubation experiments showed that BFFS significantly reduced the leaching rates by 96 % and 90 % for Cu and Pb, respectively, when compared to the control after 220 days. Speciation transformation analysis further revealed that BFFS could significantly reduce easily labile fractions of Cu and Pb, and transformed to recalcitrant fractions. Moreover, BFFS significantly improved the quality of mine soil combined with soil quality index analysis. The potential toxicity and bioavailability of Cu and Pb can still be effectively reduced by BFFS, even during a 90-day field experiment. In addition, the mine soil improved by BFFS further promoted the survival and growth of ramie. Multiple characterization analyses and related experiments indicated that ion exchange, adsorption, complexation, and coprecipitation mainly contribute to the high efficiency immobilization of Cu and Pb by BFFS. These findings could bring some fresh perspectives on the development of immobilization materials and related technologies for the economical, green and sustainable remediation of heavy metals contaminated mine soil.

Thermoresponsive supramolecular nanocontainers from ionic complexes of amphiphilic wedge-shaped mesogens and polybases

Multi-responsive polymeric nanocontainers attract significant attention for their potential applications in biotechnology, drug delivery, catalysis, and other fields. By incorporating a liquid-crystalline (LC) mesogenic ligand with an alkyl tail length ranging from 8–12 carbons, ionically linked to the polymer backbone, we generate vesicles with walls significantly thinner than those of conventional polymersomes, approaching the thickness of a lipid bilayer. These LC vesicles, ranging in size from 50–120 nm, are designed to be mechanically robust due to the alignment of the hydrophilic polymer backbone within the plane of the vesicle wall. Additionally, incorporating a temperature-sensitive block into the polymer structure imparts thermoresponsiveness to the nanocontainers, enhancing their functionality and adaptability for various applications. Ionic complexes of hydrophilic polybases, specifically poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA) and PDMAEMA-b-PNIPAM (poly(N-isopropylacrylamide)) block copolymers, with amphiphilic wedge-shaped mesogens bearing a sulfonic acid group at the focal point were synthesized. The designed nanocontainers, in the form of either vesicles or nanotubes, exhibit a well-defined wall thickness of 5 nm, dictated by the organization of a smectic LC phase. The constructed coarse-grained models elucidate the mechanism of self-assembly, demonstrating that the balance between the hydrophilicity of the main polymer chain and the hydrophobicity of the wedge-shaped pendant groups determines both the internal and external structure of the vesicles.

Graded Modulation of Inflammation by Metal Ion-Coordinated Peptide-Based Hydrogel Chemical Regulators Promotes Tendon-Bone Junction Regeneration.

After rotator cuff injuries, uncontrolled inflammation hinders tendon-bone junction regeneration and induces scar formation in situ. Therefore, precisely controlling inflammation could be a solution to accelerate tendon-bone junction regeneration. In this study, we synthesized a peptide-metal ion complex hydrogel with thermosensitive capability that can be used as a hydrogel chemical regulator. By the coordination complex between Mg2+ and BMP-12, the free and coordinated Mg2+ can be programmability released from the hydrogel. The fast release of free Mg2+ can prevent inflammation at the early stage of injuries, according to the results of RT-qPCR and immunofluorescence staining. Then, the coordinated Mg2+ was slowly released from the hydrogel and provided an anti-inflammatory environment for tendon-bone junction regeneration in the long term. Finally, the hydrogel demonstrated enhanced therapeutic effects in a rat rotator cuff tear model. Overall, the Mg2+/BMP-12 peptide-metal ion complex-based hydrogel effectively addresses the regenerative requirements of the tendon-bone junction across various stages by graded modulating inflammation.

Gingerol-zinc complex loaded 3D-printed calcium phosphate for controlled release application.

The therapeutic potential of natural medicines in treating bone disorders is well-established. Modifications in formulation or molecular structure can enhance their efficacy. Gingerol, an osteogenic active compound derived from ginger roots (Zingiber officinale), can form metal ion complexes. Zinc (Zn), a trace element that combats bacterial infections and promotes osteoblast proliferation, can be complexed with gingerol to form a G-Zn+2 complex. This study investigates a porous 3D-printed (3DP) calcium phosphate (CaP) scaffold loaded with the G-Zn+2 complex for drug release and cellular interactions. The scaffold is coated with polycaprolactone (PCL) to control the drug release. Diffusion-mediated kinetics results in 50% releaseof the G-Zn+2 complex over 6weeks. The G-Zn+2 complex demonstrates cytotoxicity against MG-63 osteosarcoma cells, indicated by the formation of apoptotic bodies and ruptured cell morphology on the scaffolds. G-Zn+2 PCL-coated scaffolds show a 1.2 ± 0.1-fold increase in osteoblast cell viability, and an 11.6 ± 0.5% increase in alkaline phosphatase compared to untreated scaffolds. Treated scaffolds also exhibit reduced bacterial colonization against Staphylococcus aureus bacteria, highlighting the antibacterial potential of the G-Zn+2 complex. The functionalized 3DP CaP scaffold with the G-Zn+2 complex shows significant potential for enhancing bone regeneration and preventing infections in low-load-bearing applications.

Synthesis, the Reversible Isostructural Phase Transition, and the Dielectric Properties of a Functional Material Based on an Aminobenzimidazole-Iron Thiocyanate Complex.

By introducing disordered molecules into a crystal structure, the motion of the disordered molecules easily induces the formation of multidimensional frameworks in functional crystal materials, allowing for structural phase transitions and the realization of various dielectric properties within a certain temperature range. Here, we prepared a novel ionic complex [C7H8N3]3[Fe(NCS)6]·H2O (1) between 2-aminobenzimidazole and ferric isothiocyanate from ferric chloride hexahydrate, ammonium thiocyanate, and 2-aminobenzimidazole using the evaporation of the solvent method. The main components, the single-crystal structure, and the thermal and dielectric properties of the complex were characterized using infrared spectroscopy, elemental analysis, single-crystal X-ray diffraction, powder XRD, thermogravimetric analysis, differential scanning calorimetry, variable-temperature and variable-frequency dielectric constant tests, etc. The analysis results indicated that compound 1 belongs to the P21/n space group. Within the crystal structure, the [Fe(NCS)6]3- anion formed a two-dimensional hydrogen-bonded network with the organic cation through S···S interactions and hydrogen bonding. The disorder-order motion of the anions and cations within the crystal and the deformation of the crystal frameworks lead to a significant reversible isostructural phase transition and multiaxial dielectric anomalies of compound 1 at approximately 240 K.

A Series of Zinc Mononuclear Complexes with Imidoyl Amidine Ligands: Syntheses, Crystal Structures, and Photoluminescence Properties

Three amidine-based ligands were used in the crystal design of a series of mononuclear Zn(II) complexes. Interaction of zinc chloride, ZnCl2, with N-2-pyridylimidoyl-2-pyridylamidine (Py2ImAm) resulted in complexes [Zn(Py2ImAm)2] (1) and [ZnCl2(Py2ImAm)] (2). In [Zn(Py2ImAm)2] (1, monoclinic, P21/c), the metal ion was coordinated with the bidentate pocket of the anionic form of Py2ImAm, while in [ZnCl2(Py2ImAm)] (2, monoclinic, P21/n), the tridentate coordination to a neutral Py2ImAm was completed by two chloride anions. This structural variation was achieved by a pH-controlling strategy using the weak base triethylamine (TEA). Otherwise, three ionic complexes were obtained with 2-amidinopyridine (PyAm) and Zinc(II), [ZnCl(PyAm)2]Cl (3, triclinic, P-1), [ZnCl(PyAm)2]2[ZnCl4]·C2H5OH (4, monoclinic, P21/n), and [ZnCl(PyAm)2]2Cl·CH3OH (5, triclinic, P-1). They comprised the same [ZnCl(PyAm)2]+ monocation with a butterfly-like shape provided by the bidentate chelate coordination of two PyAm neutral entities and a chloride ligand. In a similar butterfly shape, ionic complex [ZnCl(PmAm)2]2[ZnCl4] (6, monoclinic, C2/c) comprised the mononuclear [ZnCl(PmAm)2]+ cations with two bidentate chelate-coordinated 2-amidinopyrimidine (PmAm) as neutral ligands. The Zn(II) pentacoordinated arrangement in 3–6 was variable, from square pyramidal to trigonal bipyramidal. The reported compounds’ synthetic protocols, crystal structures and photoluminescence properties are discussed.

Diverse Microstructures and Quasi-Ionic Liquid-like Transport Mechanisms in Concentrated "Water-in-Salt" Lithium Salt Electrolytes: A Molecular Dynamics Study.

"Water-in-salt"(WIS) electrolytes as potential green and nonflammable electrolytes are currently applied in various energy storage devices, such as lithium-ion batteries and supercapacitors. However, the microstructure at molecular scale and fast ion transport mechanism in such aqueous electrolytes are still under heavy debate due to the complex interactions among ions and water. Here, molecular dynamics simulations are used to study the microstructure and ion transport behaviors from the very dilute LiTFSI/water solution to the highly concentrated WIS electrolytes. It revealed that the diverse microstructures such as completely hydrated ions, ion complexes, and bridge-water molecules are jointly responsible for the electrochemical stability of WIS electrolytes. Diffusion model analysis showed that the Li+ ions exhibit a vehicular transport mechanism with first shell water molecules and structural diffusion mechanism with TFSI- anions. The lithium ion and its first hydration shell act as a single cationic entity. The entity forms a quasi-ionic liquid-like dynamic transport structure with associated anions. Our study challenges previous findings that the high transport dynamics of lithium ions arises from their transport in water-rich nanodomains in high-concentration WIS systems.

Updates on Mechanisms of Cytochrome P450 Catalysis of Complex Steroid Oxidations.

Cytochrome P450 (P450) enzymes dominate steroid metabolism. In general, the simple C-hydroxylation reactions are mechanistically straightforward and are generally agreed to involve a perferryl oxygen species (formally FeO3+). Several of the steroid transformations are more complex and involve C-C bond scission. We initiated mechanistic studies with several of these (i.e., 11A1, 17A1, 19A1, and 51A1) and have now established that the dominant modes of catalysis for P450s 19A1 and 51A1 involve a ferric peroxide anion (i.e., Fe3+O2¯) instead of a perferryl ion complex (FeO3+), as demonstrated with 18O incorporation studies. P450 17A1 is less clear. The indicated P450 reactions all involve sequential oxidations, and we have explored the processivity of these multi-step reactions. P450 19A1 is distributive, i.e., intermediate products dissociate and reassociate, but P450s 11A1 and 51A1 are highly processive. P450 17A1 shows intermediate processivity, as expected from the release of 17-hydroxysteroids for the biosynthesis of key molecules, and P450 19A1 is very distributive. P450 11B2 catalyzes a processive multi-step oxidation process with the complexity of a chemical closure of an intermediate to a locked lactol form.

Comparative kinetic study of Pb(II) and Cd(II) metal ions removal from aqueous solutions by Lactobacillus helveticus, Limosilactobacillus fermentum, and Lactiplantibacillus pentosus

ABSTRACT In this study, selected lactic acid bacteria, including Lactobacillus helveticus, Limosilactobacillus fermentum, and Lactiplantibacillus pentosus, were evaluated for their potential to remove Pb(II) and Cd(II) ions from aqueous solutions. The highest removal efficiency was achieved at a pH value of 4. Kinetic modeling using the pseudo-first-order, pseudo-second-order, and intraparticle diffusion models demonstrated that the intraparticle diffusion model provided the best fit for describing the adsorption process. The results of the study indicated that among the three bacteria tested, L. fermentum exhibited the highest maximum adsorption capacity for Pb(II) at 4.95 mg g−1, followed by L. helveticus at 4.91 mg g−1 and L. pentosus at 4.08 mg g−1. In contrast, for Cd(II) adsorption, L. helveticus showed the highest maximum adsorption capacity at 4.38 mg g−1, followed by L. pentosus at 3.45 mg g−1 and L. fermentum at 2.86 mg g−1. The mechanism of Pb(II) and Cd(II) ions removal by LAB strains involves adsorption onto the bacterial cell surfaces, where interactions such as ion exchange, electrostatic attraction, and complexation play crucial roles. Overall, L. helveticus, L. fermentum, and L. pentosus hold promising potential for various applications in wastewater treatment, particularly in the removal of heavy metal ions.

Synthesis, crystal structure, Hirshfeld surface analysis, DFT studies and biological evaluation of bis(acetonitrile)bromido(η6-1-isopropyl-4-methylbenzene)osmium(II) hexafluoroantimonate

The complex bis(acetonitrile)bromido(η6-1-isopropyl-4-methylbenzene)osmium(II) hexafluoroantimonate, [OsBr(C10H14)(CH3CN)2]SbF6 (1) crystallizes as a triclinic system in space group P1 (no. 2), consisting of two cationic osmium(II) complex ions and two anionic hexafluoroantimonate counterions in each cell. Density Functional Theory (DFT) calculations were performed at the B3LYP/LanL2DZ and B3LYP/Def2 − SVP/Def2 − TZVP levels of theory. Reactivity descriptors and charge transfer properties were computed using frontier molecular orbital analysis. The DFT-optimized model systems from both basis sets were comparable to the experimentally determined X-ray diffraction results. Hirshfeld surface analysis shows significant non-covalent interactions including hydrogen bonds and halogen interactions. The MTT technique was utilized to conduct an in vitro cytotoxicity assay of 1 against cancerous cell lines (MCF-7 and A549) and normal cells (HEK293). Complex 1 is potent towards cancer cells as evidenced by the IC50 values of 5.02 ± 0.05 µM for MCF-7 cells and 13.36 ± 0.04 µM for A549 cells. Complex 1 demonstrated lower toxicity to normal cells with an IC50 value of 26.76 ± 0.08 µM for the HEK293 cell line compared to the doxorubicin standard with an IC50 value of 1.2 ± 0.1 µM.

Synthesis of cadmium(II) complexes with polyamines: Crystal structure, theoretical calculation, photocatalytic, DNA interaction and biological studies

Three cadmium(II) complexes of N-(2-aminoethyl)-1, 2-ethanediamine (DETA) (1), N-(3-aminopropyl)-1, 3-propanediamine (DPTA) (2) and N,N'-(ethane-1,2-diyl)bis(propane-1,3-diamine) (DPETA) (3) have been synthesized and characterized by single crystal X-ray crystallography, UV–visible spectroscopy, IR and conductivity measurements. Complexes 1 and 3 show octahedral geometry while complex 2 show five coordinated square pyramidal geometry. Two molecules of DETA ligand are coordinated to the Cd(II) ion in complex 1. But one molecule each of DPTA and DPETA ligands and two bromide ions are coordinated to the Cd(II) ions to form square pyramidal (2) and octahedral structure (3). DFT results show that complex 3 is the most favoured complex thermodynamically while complex 1 is the least. The complexes exhibit good photocatalytic activity with reference to the intensity of organic dye methylene blue. The complexes were investigated for DNA interaction by absorption and fluorescence spectroscopy suggesting both hypochromism (internal contact or intercalative interaction) and hyperchromism (external contact or electrostatic binding). The cadmium (II) complexes show growth inhibitory activity against four pathogenic bacteria, two gram +ve, viz., Staphyloccus aureus, Bacillus subtilis and two gram –ve, viz., Escherichia coli, Salmonella typhi. Albumin denaturation assay and Heat Induced Haemolysis were studied for the complexes for anti-inflammatory activity.

Mineralization and stabilization of toxic Pb2+ ions using CMC loaded S/P co-doped biochar composite

Creating more stable chemical precipitates containing lead using biochar composite represents a significant and promising strategy for the treatment of lead contamination. Biochar, a porous and carbonaceous material, was fabricated by pyrolyzing plant biomasses (i.e., soybean straw) under anoxic conditions. In this research, a high capacity of adsorbent called carboxymethyl cellulose-loaded sulfur-phosphorus co-doped biochar composite was prepared, and the optimal lead adsorption parameters and mechanism were also investigated. The experimental results showed that CMC@SP2BC exhibited excellent Pb2+ removal capacity, reaching 829.3 mg/g maximum adsorption under optimum conditions (dosage 0.5 g/L, temperature 308 K, initial pH 5, initial lead concentration 2000 mg/L), which was in agreement with the Langmuir and second-order kinetic models. Moreover, the sequential extraction results indicated that the predominant passivation mechanism for Pb was chemical precipitation, followed by ion exchange, complexation, and physical adsorption. In addition, structural characterization revealed that the passivated lead was mainly in the form of minerals such as PbSO4, Pb3(PO4)2, Pb5(PO4)3OH, and Pb5(PO4)3Cl, which was also further confirmed by PHREEQC model simulation at different pH value and Pb2+ concentrations. Finally, Pb2+ was effectively removed from actual ground water by CMC@SP2BC to achieve Class I and Class II ground water standard. The current work offers an efficient solution for immobilizing Pb2+, which has enormous promise for stabilizing heavy metals.

Novel MOF(Zr)–on-MOF(Ce/La) adsorbent for efficient fluoride and phosphate removal

A one-pot method with formic acid regulation was adopted to fabricate a novel MOF(Zr)–on-MOF(Ce/La) adsorbent for fluoride and phosphate removal. Compared to traditional adsorbents, MOF(Zr)–on-MOF(Ce/La) boasted abundant active sites and a wide application range, with adsorption capacities of 173.2 and 92.85 mg g−1 for fluoride and phosphate, respectively. Comprehensive characterization techniques like SEM-EDS, BET, XRD, FTIR, and TGA were employed to analyze the material’s properties. Adsorption experiments investigated multiple effect factors. BET analysis disclosed a specific surface area of 332 m2 g−1, mainly composed of micropores and mesopores. The adsorbent showed rapid adsorption rates for both ions, with low reliance on adsorption time. The adsorption process was exothermic and spontaneous, favored by higher temperatures. Kinetic and thermodynamic studies favored the pseudo-second-order kinetic and Langmuir models, suggesting monolayer chemical adsorption. Through combined analyses including XPS, XRD, and studies on kinetics and thermodynamics, the fluoride removal mechanism involved electrostatic interaction and ion exchange, while phosphate removal encompassed ion exchange, electrostatic interactions, and complexation. Field wastewater experiments met Chinese standards, and recycling experiments revealed sustained removal efficiencies of 90.20 % for fluoride and 87.27 % for phosphate after two regeneration cycles, highlighting the significant potential of this approach in alleviating fluoride and phosphorus pollution.

Synthesis of biobased Phosphorus-Nitrogen-Silicon ceramizable flame retardant and its flame retardancy effects on EPS

The rising interest in eco-friendly flame retardants marks a notable trend in the industry. However, the challenge remains that most flame retardants, while achieving high flame retardant properties, struggle to balance environmental sustainability and resource utilization. This work delves into the green synthesis and mechanism of action of ceramizable flame retardants. Using phytic acid (PA) and urea (U) as raw materials, ionic complexation assembly in water, employing polydopamine (PDA) as an adhesive, to develop an environmentally friendly, bio-based synergistic flame retardant (PAU) is conducted. Building upon this groundwork, the addition of the ceramic filler kaolin (KL) and the fluxing agent sodium carbonate (Na2CO3) physically modifies the PAU, resulting in a novel eco-friendly, bio-based, ceramifiable flame retardant (PAUK). Employing the prepared PAUK through an effective surface coating technique, a lightweight and scratch-resistant flame-retardant expanded polystyrene insulation board (EPS-PAUK) is created. The best EPS-PAUK composite in our study exhibits an oxygen index of 52.5, achieves a V-0 UL-94 rating, and features excellent smoke suppression and compression strength up to 67.8 kPa, while nearly maintaining the lightweight characteristics of the EPS insulation boards. This bio-based, ceramifiable flame retardant system offers a new approach for producing lightweight, highly efficient flame-retardant and high-performance polymers.