Water Molecules Research Articles

Density Functional Theory Study of the Crystal Structure and Infrared Spectrum of a Synthetized Ettringite Mineral

One of the most important hydration phases of Portland cement is ettringite, a calcium sulfo-aluminate mineral (Ca6Al2(OH)12(SO4)3·26H2O) showing a great capacity of adsorbing radionuclides and other contaminant cationic and anionic species, or incorporating them into its crystal structure. In this work, the X-ray diffraction pattern and infrared spectra of a synthetized ettringite sample are recorded and simulated, employing theoretical methods based on Density Functional Theory. Despite the complexity of this phase, the calculated structure, X-ray diffraction pattern and infrared spectrum are in excellent agreement with their experimental counterparts. Since the calculated and experimental spectra are consistent, the main infrared bands are assigned using a normal coordinate analysis, some of them being completely reassigned with respect to other experimental works. The good agreement found provides strong support for the computational methods employed towards their use for studying the surface adsorption properties and the incorporation of contaminations in its structure. The density of reactive groups at the surfaces of ettringite is reported, and the surface adsorption of water molecules is studied. These surfaces appear to be highly hydrophilic, in agreement with the experimental finding that the ettringite structure may include more water molecules, at least up to 27, one more than in its standard formula.

Structure and intermolecular interactions in ionic liquid 1-ethyl-3-methylimidazolium bromide and its aqueous solutions investigated by vibrational spectroscopy and quantum chemical computations.

The recently developed efficient protocol to explicit quantum mechanical modeling of structure and IR spectra of liquids and solutions (S. A. Katsyuba, S. Spicher, T. P. Gerasimova, S. Grimme, J. Phys. Chem. B 2020, 124, 6664) is applied to ionic liquid (IL) 1-ethyl-3-methylimidazolium bromide (EmimBr), its C2-deuterated analog [Emim-d]Br and its aqueous solutions. It is shown that the solvation strongly modifies frequencies and IR intensities of the CH/CD stretching vibrations (νCH/νCD) of the imidazolium ring. The main vibrational spectroscopic features of the neat IL are reproduced by the simulations for a cluster (EmimBr)9, in which all three imidazolium CH moieties of the solvated cation form short contacts with three Br- anions, and another two Br- anions are located on top and bottom of imidazolium ring. Cluster models of aqueous solutions reproduce the experimental vibrational frequencies of actual solutions, provided that the Br- anion of solvated contact ion pair (CIP) is situated on top of imidazolium ring, and CH/CD moieties of the latter participate in short contacts with surrounding water molecules. Both structural and spectroscopic analysis allow to interpret the short contacts CH/CD⋯Br- and CH/CD⋯OH2 as hydrogen bonds of approximately equal strength. Enthalpies of bonding of these liquid-state H-bonds, estimated with the use of empirical correlations, amount to ca. 1.4 kcal⋅mol-1, while the analogous estimates obtained for the gas-phase charged species [Emim]2Br+ increase to 5.6 kcal⋅mol-1. It is shown that formation of solvent-shared ion pair (SIP) in aqueous solution, where the counterions of IL are separated by two water molecules H-bonded to a Br- anion, produces frequency shifts ΔνCH/CD, strongly different from the case of CIP formation. This difference can be used for IR/Raman spectroscopic differentiation of the type of solvated ion pairs of EmimBr or other related ILs.

Warm red light emitting Eu(III) complexes synthesis and analysis including computational methods for photonic applications

Six luminescent europium organic complexes have been synthesized and studied for their luminescent properties. The synthesized complexes were analyzed through elemental analysis, XRD, SEM, EDAX, FT-IR, NMR and thermogravimetry. The complexes exhibit crystalline behavior and possess decent thermal stability. Photoluminescence study on complexes were conducted in both solid and solution states, the results indicate the characteristic red emission. With the addition of ancillary ligands, water molecules are replaced from inner coordination sphere, leading to enhanced luminescence properties. The colorimetric parameters (CIE, CP%, CCT, u′, v′) suggest aptness of these complexes in red light illuminating OLEDs. The J-O parameters were calculated experimentally and theoretically with the help of LUMPAC software. Theoretical and experimental results agree well reflecting the efficacy of the outcomes. As a result of red emission, these complexes could have interesting photonics applications. The biological studies indicate the probable use of these complexes in the medical industry.

Vibrational frequency fluctuations of poly(N,N-diethylacrylamide) in the vicinity of coil-to-globule transition studied by two-dimensional infrared spectroscopy and molecular dynamics simulations.

Poly(N,N-diethylacrylamide) (PdEA), one of the thermoresponsive polymers, in aqueous solutions has attracted much attention because of its characteristic properties, such as coil-to-globule (CG) transition. We performed two-dimensional infrared spectroscopy and molecular dynamics (MD) simulations to understand the hydration dynamics in the vicinity of the CG transition at the molecular level via vibrational frequency fluctuations of the carbonyl stretching modes in the side chains of PdEA. Furthermore, N,N-diethylpropionamide, a repeating monomer unit of PdEA, is also investigated for comparison. From decays of the frequency-frequency time correlation functions (FFTCFs) of the carbonyl stretching modes, we consider that inhomogeneity of the hydration environments originates from various backbone configurations of PdEA. The degree of the inhomogeneity depends on temperature. Hydration water molecules near the carbonyl groups are influenced by the confinements of the polymers. The restricted reorientation of the embedded water, the local torsions of the backbone, and the rearrangement of the whole structure contribute to the slow spectral diffusion. By performing MD simulations, we calculated the FFTCFs and dynamical quantities, such as fluctuations of the dihedral angles of the backbone and the orientation of the hydration water molecules. The simulated FFTCFs match well with the experimental results, indicating that the retarded water reorientations via the excluded volume effect play an important role in the vibrational frequency fluctuations of the carbonyl stretching mode. It is also found the embedded water molecules are influenced by the local torsions of the backbone structure within the time scales of the spectral diffusion.

Humidity‐adaptive, mechanically robust, and recyclable bioplastic films amplified by nanoconfined assembly

AbstractPoly(vinyl alcohol) (PVA) is biodegradable, recyclable, and has high tensile strength. Therefore, it is ideal for the development of environment‐friendly sustainable bioplastics. However, at elevated humidity, the mechanical properties of PVA bioplastic films undergo degradation owing to their intrinsic hydrophilic and hygroscopic nature, hindering their applications. This study proposes a nanoconfined assembly strategy to produce humidity‐adaptive, mechanically robust, and recyclable bioplastic film. The strong hydrogen bonds between PVA and cellulose nanofibrils inhibit the penetration of water molecules into the film to promote humidity resistance. Further, the robust coordination interactions between bentonite nanoplates, PVA, and cellulose nanofibrils restrict the slip of polymer chains during deformation, leading to enhanced mechanical properties. Benefiting from the nanoconfined assembly architecture in aggregated composites, the resulting reinforced PVA film simultaneously exhibits strength, stiffness, toughness, fracture energy, and tearing energy of 55.9 MPa, 1,275.6 MPa, 162.9 MJ m−3, 630.9 kJ m−2, and 465.0 kJ m−2, respectively. Moreover, the film maintains a strength of approximately 48.7 MPa even at 80% relative humidity for 180 days. This efficient design strategy applies to diverse scales and structured cellulose biomacromolecules. Moreover, it facilitates the application of recyclable high‐performance bioplastic films to settings that require high humidity tolerance.

Comparing the MP2, DKH2‐MP2 and SCAN Hybrid Forces Molecular Dynamics Simulation on the Structure and Dynamics of Hydrated Ion Ba2+ in Aqueous Solution

AbstractThe study investigated the structural and dynamical properties of hydrated ion Barium (Ba2+) in aqueous solution using quantum mechanical/molecular mechanical molecular dynamics simulations (QM/MM MD simulation). The primary objective was to assess the performance of the SCAN functional in describing the structure and dynamics of formed Ba2+ hydration shells in aqueous solution. The SCAN/MM MD simulation demonstrated the closest agreement with previously reported experimental data regarding the structural and dynamical properties of hydrated ion Ba2+. Specifically, the Ba2+ and surrounding water molecules distance was determined to be 2.79 Å, with equal distribution of coordination numbers of 8 and 9 in the first hydration shell. Moreover, the stretching frequency of 232.21 cm−1 closely matched the CCSD(T) results. The obtained results from SCAN/MM MD has a better agreement than results from MP2/MM and DKH2 MP2/MM molecular dynamics simulation. These findings underscore the potential of SCAN/MM MD simulation as a promising method for investigating the structural and dynamical properties of hydrated ions.

Defect-engineered indium-organic framework displays the higher CO2 adsorption and more excellent catalytic performance on the cycloaddition of CO2 with epoxides under mild conditions.

In order to achieve the high adsorption and catalytic performance of CO2, the direct self-assembly of robust defect-engineered MOFs is a scarcely reported and challenging proposition. Herein, a highly robust nanoporous indium(III)-organic framework of {[In2(CPPDA)(H2O)3](NO3)·2DMF·3H2O}n (NUC-107) consisting of two kinds of inorganic units of chain-shaped [In(COO)2(H2O)]n and watery binuclear [In2(COO)4(H2O)8] was generated by regulating the growth environment. It is worth mentioning that [In2(COO)4(H2O)8] is very rare in terms of its richer associated water molecules, implying that defect-enriched metal ions in the activated host framework can serve as strong Lewis acid. Compared to reported skeleton of [In4(CPPDA)2(μ3-OH)2(DMF)(H2O)2]n (NUC-66) with tetranuclear clusters of [In4(μ3-OH)2(COO)10(DMF)(H2O)2] as nodes, the void volume of NUC-107 (50.7%) is slightly lower than the one of NUC-66 (52.8%). However, each In3+ ion in NUC-107 has an average of 1.5 coordinated small molecules (H2O), which far exceeds the average of 0.75 in NUC-66 (H2O and DMF). After thermal activation, NUC-107a characterizes the merits of unsaturated In3+ sites, free pyridine moieties, solvent-free nanochannels (10.2 × 15.7 Å2). Adsorption tests prove that the host framework of NUC-107a has a higher CO2 adsorption (113.2 cm3/g at 273K and 64.8 cm3/g at 298K) than NUC-66 (91.2 cm3/g at 273K and 53.0 cm3/g at 298K). Catalytic experiments confirmed that activated NUC-107a with the aid of n-Bu4NBr was capable of efficiently catalyzing the cycloaddition of CO2 with epoxides into corresponding cyclic carbonates under the mild conditions. Under the similar conditions of 0.10mol% MOFs, 0.5mol% n-Bu4NBr, 0.5 MP CO2, 60°C and 3h, compared with NUC-66a, the conversion of SO to SC catalyzed by NUC-107a increased by 21%. Hence, this work offers a valuable perspective that the in situ creation of robust defect-engineered MOFs can be realized by regulating the growth environment.

Reaction Mechanism for CO Reduction by Mo-Nitrogenase Studied by QM/MM.

We have studied the conversion of two molecules of carbon monoxide to ethylene catalyzed by nitrogenase. We start from a recent crystal structure showing the binding of two carbon monoxide molecules to nitrogenase and employ the combined quantum mechanics and molecular mechanics approach. Our results indicate that the reaction is possible only if S2B dissociates as H2S (i.e., the charge of the FeMo cluster remains the same as in the E0 state, indicating that the Fe ions are formally reduced two steps when CO binds). Eight electrons and protons are needed for the reaction, and our mechanism suggests that the first four bind alternatively to the two carbon atoms. The C-C bond formation takes place already after the first protonation (in the E3 state). The next two protons bind to the same O atom, which then dissociates as water. In the same state (E8), the second C-O bond is cleaved, forming the ethylene product. The last two electrons and protons are used to form a water molecule that can be exchanged by S2B or by two CO molecules to start a new reaction cycle.

Acid Mediated In‐Situ Catalytic Cleavage/Making of C=N Bonds in Bis‐Hydrazone Uranyl Complexes: Exploration of Photophysical, Electrochemical, Dye Sorption Properties and DFT Studies

AbstractTwo new uranium complexes [UO2L2(H2O)] (where L2=diacetyl bis‐isonicotinoyl hydrazone) complex 1, and [UO2(L1)2] (where L1=diacetylmonoxime isonicotinoylhydrazone) complex 2, have been synthesized by precisely adjusting the pH values of the reaction system. Complex 1 was formed in an acidic ethanolic solution (pH=3) through an in‐situ acid catalytic reaction of diacetylmonoxime isonicotinoylhydrazone and UO2(NO3)2.6H2O, while complex 2 was acquired in a neutral medium (pH=7) through self‐assembly of two ligands and one uranium (VI) metal centre. Both complexes were thoroughly characterized by elemental analysis, UV‐Visible spectroscopy, IR spectroscopy, NMR, TGA, cyclic voltammetry, and powder X‐ray diffraction. The studies indicate that the bis‐hydrazone in complex 1 is a dianionic tetradentate N2O2 donor, whereas in complex 2 it is a monoanionic tridendate N2O donor. The formation of complex 1 was further confirmed by a single‐crystal X‐ray diffraction study, which revealed the role of a water molecule in forming a pentagonal bipyramidal geometry of [UO2L2(H2O)]. Photophysical studies revealed that complexes 1 and 2 exhibited low band gap values of 2.07 and 2.12 eV, respectively, indicating their semiconducting nature. From the CV measurements, the higher negative potentials of the complexes 1 & 2 {1, −0.6 V and 2, −0.5 V vs. ferrocenium/ferrocene (Fc+/Fc)} in DMSO are assigned to the presence of {UO2}2+/{UO2}+ couple signifying their redox active nature. Dye adsorption studies show that both the complexes were able to remove 90 % of Methylene blue (MB) and Rhodamine B (RhB) from the solutions with the concentration of 10−5 M. The structural insights and electronic properties of Ligand HL1 and complex 1 were further explored by density functional theory (DFT) calculations.

Molecular Dynamics Simulation Investigation of Freezing Point Depression in NaClO4 Electrolyte Solution by CaCl2.

The development of inorganic antifreeze electrolytes is of paramount importance for the application of sodium-ion batteries under low-temperature conditions. However, there is little reported about their molecular mechanism for lowering the freezing point of electrolytes. Therefore, this study explores the mechanism by which CaCl2 lowers the freezing point of the NaClO4 electrolyte. Hexagonal ice (ice Ih) was used as the ice seed, and CaCl2 was selected as the antifreeze agent. The coexistence system of ice and solution was constructed to simulate the freezing process. It was found that there is ion rejection at the ice layer, with ions predominantly distributed in the solution. Over time, ions form an ion adsorption layer at the ice-solution interface. The radial distribution function (RDF) and spatial distribution function (SDF) of Na+, ClO4-, Ca2+, and Cl- revealed that ions form the first solvation shells with water molecules. The interaction energy between ions and water molecules is greater than that between ice nuclei and water. Therefore, ions are better able to maintain the stability of their solvation shells and inhibit the growth of ice Ih through a mechanism of competition for water molecules. Furthermore, the dissolution free energy of Na+ and Ca2+ in the aqueous phase was studied. The results indicated that Ca2+ has a stronger affinity for water molecules than Na+, making it more competitive in competing for water with ice Ih. Therefore, CaCl2 in NaClO4 solution can reduce the freezing point. This work provides a molecular-level understanding of how CaCl2 reduces the freezing point of NaClO4 solution, which is beneficial for designing strategies for low-temperature electrolytes.

Effect of humidity on atmospheric pressure humid air discharge—interpretation from the perspective of detachment reactions

Detachment reactions have an important influence on the decreasing trend of electron density after high-field excitation, yet existing studies on humidity’s impact on discharge have failed to address this issue. To bridge this gap, we utilize a validated global model to explore how species density changes during humid air discharge corona inception. Our results indicate that humidity influences the detachment reaction rate by altering the negative ion composition. In dry conditions, the primary species involved in detachment reactions is O− ions. However, in environments with higher water vapor density, O− ions primarily react with water molecules, depleting O− ions. This change results in H− ions becoming the main detachment negative ions during the pulse. The greater the rate of the Detachment reaction the slower the decrease in electron density, and a rise in humidity causes the Detachment reaction to peak at a higher value and have a shorter duration, thus causing the electron density to decrease more rapidly. This discovery offers fresh insights into humidity’s effect on discharges. Additionally, we introduce the concept of the average negative ion detachment reaction rate constant, denoted as k d, to quantify the impact of detachment reactions within the three-element model.

Tribovoltaic Effect Strengthened Microwave Catalytic Antibacterial Composite Hydrogel.

Microwave (MW) therapy is an emerging therapy with high efficiency and deep penetration to combat the crisis of bacterial resistance. However, as the energy of MW is too low to induce electron transition, the mechanism of MW catalytic effect remains ambiguous. Herein, a cerium-based metal-organic framework (MOF) is fabricated and used in MW therapy. The MW-catalytic performance of CeTCPP is largely dependent on the ions in the liquid environment, and the electron transition is achieved through a "tribovoltaic effect" between water molecules and CeTCPP. By this way, CeTCPP can generate reactive oxygen species (ROS) in saline under pulsed MW irradiation, showing 99.9995 ± 0.0002% antibacterial ratio against Staphylococcus aureus (S. aureus) upon two cycles of MW irradiation. Bacterial metabolomics further demonstrates that the diffusion of ROS into bacteria led to the bacterial metabolic disorders. The bacteria are finally killed due to "amino acid starvation". In order to improve the applicability of CeTCPP, It is incorporated into alginate-based hydrogel, which maintains good MW catalytic antibacterial efficiency and also good biocompatibility. Therefore, this work provides a comprehensive instruction of using CeTCPP in MW therapy, from mechanism to application. This work also provides new perspectives for the design of antibacterial composite hydrogel.

Intra-annual variations in isotopic composition of atmospheric water vapour in a semi-arid monsoon region: observations and inferences

The isotopic composition of atmospheric water vapour dynamically changes due to the complex interplay between the moisture-contributing sources (precipitation, evaporating soil moisture, transpiration, evaporating water bodies, etc.), operating ecohydrological processes, and the climatic conditions. In the present study, the isotopic composition of different sources of water was sampled; air moisture (n = 47) twice a month for the period December, 2021 to January, 2023; transpiration samples (n = 76); evaporation and rain samples (n = 12 each). The samples were analyzed using the mass spectrometry to investigate the dynamic nature of the isotopic composition of the atmospheric vapour and the factors influencing it. The research findings showed that the isotopic composition of atmospheric moisture rapidly depleted after the onset of the monsoon, indicating the replacement of pre-monsoon local vapour by monsoon moisture of depleted isotopic composition. The process of evaporation from the soil surface during the post-monsoon period was found to progress parallel to other soil hydrological processes, such as capillary action and diffusion-driven downward flux of enriched water molecules. This resulted in the broadening of an isotopically enriched layer of soil moisture in the vadose zone with time, and accordingly, there was transpiration of this enriched soil moisture from the deeper layers of soils with time by plants/trees. Evaporation of soil water and the transpiration of plants and trees of enriched water vapour gradually altered the isotopic composition of the atmospheric water vapour composition from the depleted isotopic composition of the monsoon period to an enriched isotopic composition. The transpiration of enriched water vapour from deep-rooted trees indicated more prolonged arid climate conditions. The findings of the study are useful in understanding the regional hydrological and hydroclimatic processes which can be implemented in agro-climatic studies and water resource management.

The solvation shell probed by resonant intermolecular Coulombic decay

Molecules involved in solvation shells have properties differing from those of the bulk solvent, which can in turn affect reactivity. Among key properties of these molecules are their nature and electronic structure. Widely used tools to characterize this type of property are X-ray-based spectroscopies, which, however, usually lack the capability to selectively probe the solvation-shell molecules. A class of X-ray triggered “non-local” processes has the recognized potential to provide this selectivity. Intermolecular Coulombic decay (ICD) and related processes involve neighbouring molecules in the decay of the X-ray-excited target, and are thus naturally sensitive to its immediate environment. Applying electron spectroscopy to aqueous solutions, we explore the resonant flavours of ICD and demonstrate how it can inform on the first solvation shell of excited solvated cations. One particular ICD process turns out to be a potent marker of the formation of ion pairs. Another gives a direct access to the electron binding energies of the water molecules in the first solvation shell, a quantity previously elusive to direct measurements. The resonant nature of the processes makes them readily measurable, providing powerful new spectroscopic tools.

Effects of quaternization sites and crossing methods on the slow-release and antibacterial effects of hydroxypropyltrimethyl ammonium chloride chitosan/dialdehyde chitosan-based film

In this study, the active food packaging film were prepared using hydroxypropyltrimethyl ammonium chloride chitosan with different substitution sites (O-HACC & N-HACC) and dialdehyde chitosan (DCS) grafted with protocatechuic acid (PA). To explore the effect of chitosan quaternization positions and crosslinking approaches on the slow-release and antibacterial properties, the double-crosslinked film were fabricated through the self-coupling reaction of PA and Schiff base reaction between amino groups on HACC and aldehyde groups on DCS. The HACC/DCS-based film exhibited stable porous three-dimensional networks with high nisin loading ratios (>90 %). With the participation of the catechol-catechol structure, the dense double-crosslinked film effectively restricted the diffusion of the water molecules, resulting in excellent slow-release properties fitting with the Korsmeyer-Peppas kinetic model. Especially, O-HACC/PA-g-DCS film, which had more reaction sites for Schiff base crosslinking than N-HACC, exhibited the equilibrium swelling ratio of 800 % at 60 h and could sustainably release nisin via non-Fickian diffusion behavior until 48 h. Moreover, the HACC/DCS-based double-crosslinked film performed good long-time antibacterial activity and preservation effects on salmon. On the 10th day of storage, the TVBN of N-HACC/PA-g-DCS and O-HACC/PA-g-DCS groups were only 28.26 ± 1.93 and 29.06 ± 1.68 mg/100 g and still lower than the thresholds.

Nanocellulose and multi-walled carbon nanotubes reinforced polyacrylamide/sodium alginate conductive hydrogel as flexible sensor

Conductive hydrogels have been widely applied in human–computer interaction, tactile sensing, and sustainable green energy harvesting. Herein, a double cross-linked network composite hydrogel (MWCNTs/CNWs/PAM/SA) by constructing dual enhancers acting together with PAM/SA was constructed. By systematically optimizing the compositions, the hydrogel displayed features advantages of good mechanical adaptability, high conductivity sensitivity (GF = 5.65, 53 ms), low hysteresis (<11 %), and shape memory of water molecules and temperature. The nanocellulose crystals (CNWs) were bent and entangled with the backbone of the polyacrylamide/ sodium alginate (PAM/SA) hydrogel network, which effectively transferred the external mechanical forces to the entire physical and chemical cross-linking domains. Multi-walled carbon nanotubes (MWCNTs) were filled into the cross-linking network of the hydrogel to enhance the conductivity of the hydrogel effectively. Notably, hydrogels are designed as flexible tactile sensors that can accurately recognize and monitor electrical signals from different gesture movements and temperature changes. It was also assembled as a friction nanogenerator (TENG) that continuously generates a stable open circuit voltage (28 V) for self-powered small electronic devices. This research provides a new prospect for designing nanocellulose and MWCNTs reinforced conductive hydrogels via a facile method.

Molecular insight into oil displacement by CO2 flooding in water-cut dead-end nanopores.

Understanding the mechanisms underlying residual oil displacement by CO2 flooding is essential for CO2-enhanced oil recovery. This study utilizes molecular dynamics (MD) simulations to investigate the displacement of residual oil by CO2 flooding in dead-end nanopores, focusing specifically on the water-blocking effect. The findings reveal that oil displacement does not commence until the water film is breached. The dissolution of CO2 molecules in water and the hydrogen bond interactions between water and rock are the primary factors that disrupt the hydrogen bond network among the water molecules, facilitating the breakthrough of the water film. Additionally, the displacement process can be delineated into four distinct stages - encompassing water film rupture, oil swelling, massive oil displacement, and displacement completion - as evidenced by the oil recovery-displacement time curves. Moreover, a cutting-edge oil recovery-displacement time model precisely quantifies crucial stages in the displacement process. For example, when t < δ, trapped oil is impeded by the water film, while when t > δ + 3τ, displacement culminates successfully. Altogether, this research bolsters comprehension of residual oil displacement in the presence of water blocking and advocates for sustainable oil production strategies in oilfields.

Bionic repair protective coatings with high toughness and bond strength based on anionic waterborne polyurethane-modified cement

Protection and repair of surface cracks play pivotal roles in enhancing their effective service life. Inspired by the bionic shell principle, an anionic waterborne polyurethane (WPU) was designed. The Synthetic WPU was applied to sulphoaluminate (SAC) and ordinary Portland (OPC) cements to prepare composite coatings. The results showed that with the increase in polymer-to-cement ratio (P/C), attributable to the electrostatic adsorption and complexation of R-COO-, the content of CH, AH3 and AFm increased, while the content of AFt decreased due to the inhibitory effect of WPU on hydration reactions. The molecular dynamics model indicated that the oxygen atoms in WPU can not only form ion pairs with Ca2+ in AFt but also form strong hydrogen bonds with the H in the hydroxyl group of AFt and the H in water molecules. Hence, for P/C exceeding 10 %, combined with Flory-Huggins theory, a continuous interpenetration polymer network (IPN) comprising multiphase composites was successfully demonstrated, bolstered by the macromolecular structure composed of —OH, —COOH, Ca2+ and Al3+ serving as a bridge. The network was more pronounced in coatings with SAC than in those with OPC due to synergistic effects caused by rapid hydration reactions. Due to the presence of IPN and the Si-O-Si bonds caused by the hydrolysis condensation reaction of silane coupling agent, the tensile and bond strengths exhibited an upward trend with increasing P/C, surging by up to 326 % and 180 %, respectively. The value reached 6.81 MPa and 2.2 MPa. And the addition of WPU enhanced crack resistance.

A Robust In Vitro Anti‐tuberculosis, Antimicrobial, and Anti‐inflammatory Activities Based on Azomethine Chelates Incorporating Co(II), Ni (II), Cu(II), and Zn(II) Ions: Synthesis, Characterization, and Investigation of the Aspects of Docking Interaction

ABSTRACTIn recent times, there has been a growing exploration of transition metal complexes as potential solutions for significant health challenges, including tuberculosis, microbes infection, and inflammation. Therefore, in our ongoing effort to identify biologically effective agents, Co(II), Ni(II), Cu(II), and Zn(II) metal complexes of H2L1–H2L2 hydrazone ligands were synthesized. The structural features of synthesized compounds were recognized by employing several techniques such as FT‐IR, 1H NMR, 13C NMR, powder x‐ray diffraction (XRD), UV‐Vis, ESR, TG‐DTA, mass spectrometry, and molar conductance measurements. The bonding of ligands via Ophenolic, Oenolic, and Nazomethine donor atoms and the attachment of the three water molecules with metal ion to form the octahedral structure of complexes were corroborated by different spectroscopic techniques. The anti‐tuberculosis, antimicrobial, and anti‐inflammatory activities of the synthesized compounds were assessed using the microplate alamar blue assay, serial dilution, and bovine serum albumin (BSA) methods, respectively, and highlighted the more potency of the complexes than ligands. The synthesized Cu(II) (9) and Zn(II) (10) metal complexes exhibited excellent ability to inhibit the growth of H37Rv strain of Mycobacterium tuberculosis in comparison to standard drug streptomycin. The Cu(II) (6 and 9) and Zn(II) (10) complexes showed superb ability as antimicrobial agents, whereas Cu(II) (5) and Zn(II) (6) complexes exhibited significant anti‐inflammatory ability. The in vitro findings on the antituberculosis activity were reinforced by a significant molecular docking study, which has become a crucial component of computational research utilizing the enzyme Mtb Pks13 thioesterase domain of M. tuberculosis. Additionally, in this research work, the absorption–distribution–metabolism–excretion–toxicity (ADMET) study sparked the compounds' drug‐like behavior.

Improvements and Challenges of Hydrogel Polymer Electrolytes for Advanced Zinc Anodes in Aqueous Zinc-Ion Batteries.

Aqueous zinc-ion batteries (AZIBs) are widely regarded as desirable energy storage devices due to their inherent safety and low cost. Hydrogel polymer electrolytes (HPEs) are cross-linked polymers filled with water and zinc salts. They are not only widely used in flexible batteries but also represent an ideal electrolyte candidate for addressing the issues associated with the Zn anode, including dendrite formation and side reactions. In HPEs, an abundance of hydrophilic groups can form strong hydrogen bonds with water molecules, reducing water activity and inhibiting water decomposition. At the same time, special Zn2+ transport channels can be constructed in HPEs to homogenize the Zn2+ flux and promote uniform Zn deposition. However, HPEs still face issues in practical applications, including poor ionic conductivity, low mechanical strength, poor interface stability, and narrow electrochemical stability windows. This Review discusses the issues associated with HPEs for advanced AZIBs, and the recent progresses are summarized. Finally, the Review outlines the opportunities and challenges for achieving high performance HPEs, facilitating the utilization of HPEs in AZIBs.