Electrostatic Interaction Forces Research Articles

Exploiting RSM and ANN modeling methods to optimize phosphate ions removal using LDH/alginate composite beads

In the present work, layered double hydroxide (MgAl) and alginate composite beads (LDH/alginate) were developed and used as low-cost and environmentally friendly adsorbent for phosphate ions removal. The successful incorporation of sodium alginate into the LDH structure was confirmed through SEM analysis. The dried beads exhibited a notably rough surface, which promotes molecular movement and potentially enhances pollutant adsorption. The pH of zero charge point (pHPZC) of the composite was found to be 7.41. This result implies that negative ions have a tendency to draw positive charges on the adsorbent surface via electrostatic interaction forces when the pH is lower than the pHPZC. On the other hand, a surface that has a pH higher than pHPZC mostly has a negative charge. The percentage removal and adsorption capacity were investigated as a function of contact time.Experiments were carried out by simultaneously varying three factors, in order to evaluate and compare the predictive capabilities of the response surface methodology (RSM) and the artificial neural network approach (ANN) for the adsorption process. Both methods demonstrated a strong ability to accurately predict the adsorption process. However, the response surface methodology exhibited a lower prediction error compared to the artificial neural network approach.The central composite design within response surface methodology (CCD-RSM) was employed to optimize the experimental conditions for the adsorption process. The model, which considers three factors: adsorbent dose (A), initial concentration (B), and contact time (C), proved to be significant. Among these, the quadratic term (B2) had the most substantial impact on the phosphate ion adsorption rate. The analysis yielded an R2 value of 0.94, indicating an excellent fit to the data. The findings suggest that increasing contact time and reducing the initial concentration improve phosphate ion removal efficiency, while the adsorbent dose has little to no effect. The Artificial Neural Network (ANN) model effectively predicted the adsorptive remediation of phosphate ions onto LDH/alginate composite beads, achieving a high coefficient of determination (R2 = 0.984) between the model outputs and the experimental data. The study highlights the significant potential of LDH/alginate composite beads as a natural adsorbent for the removal of phosphate ions from aqueous solutions. These results underscore the environmental friendliness and efficiency of the adsorbent used for phosphate adsorption.

In-situ growth of Fe-MOF on magnetic materials by self-template method to enhance practicality and removal of tetracycline antibiotics from aqueous solution

In this work, core–shell structured Fe3O4@PCN-333 (Fe) composite was constructed using a self-template method, in which Fe3O4 microspheres not only serve as magnetic centers but also provide Fe (III) for the preparation of PCN-333 (Fe). PCN-333 (Fe) uniformly grew as a shell on the surfaces of the microspheres, and the shell thickness was approximately 38 nm. The composite exhibited high adsorption performance, with maximum adsorption capacities of 471.7, 303.3 and 314.5 mg/g for chlortetracycline, tetracycline and oxytetracycline, respectively. The adsorption of tetracycline antibiotics (TCs) was based on the Langmuir and pseudo-second-order model, and external diffusion and pore diffusion were the rate-limiting steps in adsorption. The strong adsorption capacity was attributed to the mechanism of π–π interaction, coordination bonds, electrostatic interaction, hydrogen bonding, and van der Waals force. Fe3O4@PCN-333 (Fe) composite displayed good stability in the aqueous solution, strong TCs adsorption capacity, high selectivity, anti-interference performance for adsorbing TCs, fast recovery with external magnetic field, reusability, thus effectively reducing the cost for removing water pollutants. These features make the composite a potential material for removing TCs in the environment.

The Sword of Damocles: Microplastics and the molecular dynamics of sulfamonomethoxine revealed

In recent years, the environmental impact of microplastics (MPs) and antibiotics (ATs) as pollutants cannot be ignored. In order to evaluate the carrier effect of MPs in the aqueous environment, three MPs, polyamide (PA), polyethylene (PE) and polyethylene terephthalate (PET), were selected in this study, and their structures were analyzed by means of characterization. A preliminary description of their interactions with sulfamonomethoxine was carried out by adsorption kinetics and isotherm fitting. The dominance of non-bonding capacity (van der Waals and electrostatic interaction forces) in the adsorption process was demonstrated using molecular dynamics (MD) simulations and density functional theory (DFT), with the interaction strengths ranked as PA > PE > PET, respectively. PA is less adsorbent stable at the molecular level but exhibits the largest adsorption capacity influenced by the characterized structure and multiple interaction forces. PET possesses a stronger stability and is not easily replaced by other substances. This will help to further understand the complex effect mechanism between MPs and organic pollutants, and provide an important reference for the prevention and control of environmental pollution.

A highly accurate analytical method for determination of the vibrational frequency of N/MEMS with electrostatic and van der Waals interaction forces

A highly accurate analytical method for determination of the vibrational frequency of N/MEMS with electrostatic and van der Waals interaction forces

The potential of Gd doping as a promising approach for enhancing the adsorption properties of nickel-cobalt ferrites.

The study shows that the addition of gadolinium ions has a significant impact on the structure, morphology, and adsorption properties of Ni-Co spinel ferrite that was synthesized by the sol-gel auto-combustion method. The research also indicates that the higher the Gd content, the greater the increase in the lattice parameter, which suggests that Gd3+ ions uniformly replaced the octahedral Fe3+ ions. The morphology and chemical composition of Gd-doped Ni-Co ferrites have been studied using SEM and EDS. Gd adding to the NiCoFe matrix increases the BET surface area by 50% (from 48 to 72 m2/g) and promotes the formation of mesopores with an average radius from 3.9 to 4.9nm. The pHPZC values of Gd-doped ferrites are in the range of 7.22-7.39, which means that the ferrite surface will acquire a positive charge at natural pH, so this will promote the adsorption of Congo red anionic dye through electrostatic interaction forces. Langmuir, Freundlich, and Dubinin-Radushkevich models were used to explain the mechanism of CR adsorption on the Ni0.5Co0.5GdxFe2-xO4 adsorbent surface. The ionic-covalent parameter has been estimated to describe the surface acid-base properties. Overall, this study highlights the potential of Gd3+ doping as a promising approach for enhancing the adsorption properties of nickel-cobalt ferrites.

The design of molecularly dispersed tungstovanadate catalyst via ionic liquid linkers for oxidative desulfurization

The sulfur removal process in diesel is one of the key technologies to produce clean energy using polyoxometalate (POM)-based catalyst with excellent catalytic active sites. Herein, a molecularly dispersed POM supported catalyst CNT@(C4mim)4VW12O40 (CNT@C4VW12) was designed by introducing imidazole ionic liquids (IL) [C4mim]Br as counterionic linkers for oxidation desulfurization (ODS). For the model oil, 100 % desulfurization rate and product selectivity can be achieved within 30 min, and it can be recycled for 5 times without obviously decrease. Moreover, CNT@C4VW12 also displayed excellent performance in real hydrotreated diesel with a removal rate of 97.4 %. Overall, a stable and molecularly dispersed catalyst was constructed by the cooperative effect of π-π stacking, hydrogen bonding and electrostatic force interaction among the CNT, [C4mim]+ and [VW12O40]4−, which would provide new inspirations for design of heterogeneous catalyst towards excellent ODS process.

Dual-Responsive "Egg-Box" Shaped Microgel Beads Based on W1/O/W2 Double Emulsions for Colon-Targeted Delivery of Synbiotics.

In this study, for enhancing the resistance of probiotics to environmental factors, we designed a microgel beads delivery system loaded with synbiotics. Multiple droplets of W1/O/W2 emulsions stabilized with zein-apple pectin hybrid nanoparticles (ZAHPs) acted as the inner "egg," whereas a three-dimensional network of poly-L-lysine (PLL)-alginate-CaCl2 (Ca) crosslinked gel layers served as the outermost "box." ZAHPs with a mass ratio of 2:1 zein-to-apple pectin showed excellent wettability (three-phase contact angle = 89.88°). The results of the ζ-potentials and Fourier transform infrared spectroscopy demonstrate that electrostatic interaction forces and hydrogen bonding were the main forces involved in the formation of ZAHPs. On this basis, we prepared W1/O/W2 emulsions with other preparation parameters and observed their microstructures by optical microscopy and confocal laser scanning microscope. The multi-chambered structures of W1/O/W2 emulsions were successfully visualized. Finally, the W1/O/W2 emulsions were coated with PLL-alginate-Ca using the solution extrusion method. The results of the in vitro colonic digestion stage reveal that the survival rate of probiotics in the microgel beads was about 75.11%, which was significantly higher than that of the free. Moreover, probiotics encapsulated in microgel beads also showed positive storage stability. Apple pectin would serve as both an emulsifier and a prebiotic. Thus, the results indicate that the "egg-box" shaped microgel beads, designed on the basis of pH-sensitive and enzyme-triggered mechanisms, can enhance the efficiency of probiotics translocation in the digestive tract and mediate spatiotemporal controlled release.

The pH dependent structural and viscoelastic behavior of Ovomucin-Complex isolated from egg white under alkaline conditions

Ovomucin-Complex (OVM) is responsible for providing the natural gel-like properties of egg white, especially in alkali-induced egg white gels. In this study, OVM was modified by alkaline to produce gel-type materials. The structure, physicochemical and viscoelastic properties of OVMs under different pH (7–12) were probed using FTIR, HPLC, SEM, CLSM and rheometer. The results of rheological measurements in linear viscoelastic region revealed that alkaline modified OVMs exhibited a soft viscoelastic gel in alkaline conditions, with the transition occurring near pH 8, compared with a viscoelastic solution at neutral pH. In addition to the pH-dependent gelation behavior of OVMs, further rheological studies under nonlinear deformations reveal shear thinning and an apparent yield stress, which were also highly affected by pH. The results from HPLC and molecular interactions suggest that the alkaline modification led to the depolymerization of OVMs in alkaline conditions, enhancing the formation of intermolecular disulfide bonds, electrostatic force and hydrophobic interactions. The differences in these mechanical properties were also reflected in the OVM structure. The SEM and CLSM images demonstrated that the arrangement of gel pores under pH 10 conditions is denser and well-distributed than those under other conditions. The FTIR results verified that alkaline modification leads to the decreased content of β-sheet. Nevertheless, prolonged exposure to pH 12.0 resulted in a gradual liquefaction of the gel due to increased electrostatic repulsion and surface hydrophobicity, as well as the reduced disulfide bond and an increase in the disordered structure. These findings provide a novel insight for the development of mucin gel foods.

Dual-template magnetic molecularly imprinted polymers for selective extraction and sensitive detection of aflatoxin B1 and benzo(α)pyrene in environmental water and edible oil

The coexistence of multiple contaminates in the environment and food is of growing concern due to their extremely hazard as a well-known class I carcinogen, like aflatoxin B1 (AFB1) and benzo(α)pyrene (BaP). AFB1 and BaP are susceptible to coexistence in environmental water and edible oil, posing a significant potential risk to environmental monitoring and food safety. The remaining challenges in detecting multiple contaminates include unsatisfied sensitivity, insufficient targets selectivity, and interferences in complex matrices. Here, we developed dual-template magnetic molecularly imprinted polymers (DMMIPs) for selective extraction of dual targets in complex matrices from the environment and food. The DMMIPs were fabricated by surface imprinting with vinyl-functionalized Fe3O4 as carrier, 5,7-dimethoxycoumarin and pyrene as dummy templates, and methacrylamide as functional monomer. The DMMIPs showed excellent adsorption ability (12.73–15.80 mg/g), imprinting factors (2.01–2.58), and reusability of three adsorption-desorption cycles for AFB1 and BaP. The adsorption mechanism including hydrogen bond, electrostatic interaction and van der Waals force was confirmed by physical characterization and DFT calculation. Applying DMMIPs in magnetic solid phase extraction (MSPE) followed by high-performance liquid chromatography (HPLC) analysis enabled detection limits of 0.134 μg/L for AFB1 and 0.107 μg/L for BaP. Recovery rates for water and edible oil samples were recorded as 86.2%–110.3% with RSDs of 4.1%–11.9%. This approach demonstrates potential for simultaneous identification and extraction of multiple contaminants in environmental and food.

Electro-responsive OCNT/PPy membrane for efficient irreversible-fouling control through electroregulation of electrostatic and fluid interaction forces

Membrane-based separation process has been proven to be a powerful strategy for low-energy-consumption and high-efficiency water purification. However, the practical application is still subjected to serious membrane fouling. In this study, an impressive approach to alleviate membrane fouling is proposed using an electro-conductive oxygenated carbon nanotube/polypyrrole (OCNT/PPy) membrane combining electrically-regulated electrostatic and fluid forces. Benefiting from the negative potential (−1.18 V vs. SCE) applied on the membrane, the electric polarization effects significantly enhance the repulsive electrostatic force on contaminant. The transmembrane pressure increases at an ignorable rate during the filtration process. Meanwhile, for accumulated irreversible membrane fouling after multi-cycle filtrations, the positive potential (+1.19 V vs. SCE) exerted on OCNT/PPy membrane can decrease the fluid resistances of backwash flow. As a result, the electrically-regulated hydraulic backwash achieves a thorough recovery rate of permeance at 99.1 %. The numerical analysis of the antifouling mechanism reveals that the mitigation of irreversible membrane fouling is mainly attributed to rapid formation of a loose cake layer under electrical assistance. Moreover, the computational fluid dynamics verifies that the reduction of water-channel resistance enhances the elimination of foulants in membrane pores. This work motivates a new thought for membrane fouling control through electroregulation of electrostatic and fluid forces at the membrane-water interface.

New perspective into the interaction behavior explore of Nano-berberine with alpha-lactalbumin in the presence of beta-lactoglobulin: Multi-spectroscopic and molecular dynamic investigations

The present study was focus on the interaction of alpha lactalbumin (α-LA) and Nano-berberine (Nano-Ber) in the absence and presence of beta lactoglobulin (β-LG) as binary and ternary systems by the exertion of different spectroscopic techniques, conductometry, β-galactosidase activity, and molecular simulation measurements. The outcomes of fluorescence quenching clarified the dominance of static quenching mechanism throughout the interaction of α-LA-Nano-Ber and (α-LA-β-LG) Nano-Ber complexes and also determined the KSV values to be (4.68±0.05) × 104 and (5.18±0.06) × 104 M−1, respectively. The measured thermodynamic parameters exhibited the participation of electrostatic forces in the binding interaction of α-LA and α-LA-β-LG complex with Nano-Ber. Moreover, the negative value of ΔG0 represents the spontaneous mode of this binding process in both systems. Synchronous fluorescence and resonance light scattering data demonstrated the impact of β-LG attendance on altering the interaction behavior of α-LA and Nano-Ber. The changes in the secondary structure of both proteins were affirmed by circular dichroism spectroscopy (CD) technique. According to the displayed β-galactosidase activity in the Michaelis-Menten plot of both binary and ternary systems, a greater Vmax refers to the stronger affinity of lactose and lactose hydrolysis that can be effective on the lactose intolerance regarding dairy products. Additionally, molecular dynamic simulations were employed to simulate the atomic-level interactions and explore the stability and conformational changes of protein-Nano Ber complexes over time. The results of these comprehensive biophysical investigations shed light on the binding characteristics, structural alterations, and dynamic behavior of Nano-Ber upon interaction with α-lactalbumin in the absence and presence of β-lactoglobulin as the binary and ternary systems. This study reveals the Nano-Ber role in the protein–protein interaction behavior and provides valuable insights into the potential applications of α-lactalbumin in the design of functional food formulations and drug delivery systems

Understanding Aβ Peptide Binding to Lipid Membranes: A Biophysical Perspective.

Aβ peptides are known to bind neural plasma membranes in a process leading to the deposit of Aβ-enriched plaques. These extracellular structures are characteristic of Alzheimer's disease, the major cause of late-age dementia. The mechanisms of Aβ plaque formation and deposition are far from being understood. A vast number of studies in the literature describe the efforts to analyze those mechanisms using a variety of tools. The present review focuses on biophysical studies mostly carried out with model membranes or with computational tools. This review starts by describing basic physical aspects of lipid phases and commonly used model membranes (monolayers and bilayers). This is followed by a discussion of the biophysical techniques applied to these systems, mainly but not exclusively Langmuir monolayers, isothermal calorimetry, density-gradient ultracentrifugation, and molecular dynamics. The Methodological Section is followed by the core of the review, which includes a summary of important results obtained with each technique. The last section is devoted to an overall reflection and an effort to understand Aβ-bilayer binding. Concepts such as Aβ peptide membrane binding, adsorption, and insertion are defined and differentiated. The roles of membrane lipid order, nanodomain formation, and electrostatic forces in Aβ-membrane interaction are separately identified and discussed.

Boosting Zn2+ intercalation in manganese oxides for aqueous zinc ion batteries via delocalizing the d-electrons spin states of Mn site

Rechargeable aqueous zinc-ion batteries (AZIBs) have received increasing attention on account of their eco-friendliness and low cost. However, the limited capacity and poor rate properties of cathodes remain a major challenge due to the low electrochemical reactivity of cathode materials and sluggish Zn2+ transport kinetics. Herein, we design a 1,5-naphthalenediamine (NAPD) pre-intercalate potassium manganese dioxide (KMO-NAPD) with high capacity and rate capability for AZIBs. The introduction of NAPD can delocalize the d-electrons spin states of the Mn site and activate the reactivity of KMO-NAPD for Zn2+ intercalation. Moreover, the interaction between intercalated Zn2+ and KMO-NAPD is weakened due to the decreased electrostatic interaction force, which promotes the diffusion of Zn2+. Consequently, the KMO-NAPD cathode exhibits high specific capacity (237 mAh g−1 at 1 A g−1) satisfying rate capability (129 mAh g−1 at 4 A g−1), and excellent cycling stability (85 % capacity retention after 1000 cycles). Furthermore, the fabricated AZIBs based on the KMO-NAPD exhibit a high energy density of 294.3 Wh kg−1 and a peak power density of 8.6 kW kg−1. This study opens up a new path for the development of high-energy organic-inorganic hybrid cathode materials with modulated electronic structures for advanced AZIBs.

THE DEPENDENCE OF ACID-BASE EQUILBRIA AND ACIDITY CONSTANTS OF CONGO RED IN BUFFER SOLUTIONS ON THE IONIC STRENGTH

In this study, the spectrophotometric studies of aqueous ethanol solution of Congo red in various buffers solutions at room temperature 25oC and at different ionic strength of 0.05, 0.1, 0.3, and 0.5 KCl mol L-1 were investigated. The acidity constants of Congo red were estimated by three different methods. The two protonation stages were observed in pH range 2 - 4 and 4 - 6 as result as protonation of amino group and azo groups. The dependence of absorption spectra of Congo red on the ionic strength of solutions which exhibited blue shift with increases ionic strength in addition the shape and intensity were varied. Therefore, the acid-base equilibria shifted toward the higher pHs with the rise in ionic strength. Also, the acidity constants were affected by the ionic strength which the acidity constants decrease with increasing ionic strength of solution because the electrostatic interaction force increased.

Functional metal-organic framework membranes with uniform unsaturated pyridine-nitrogen sites as separators for high-performance lithium metal batteries

Lithium metal batteries are a promising successor to lithium-ion batteries due to high specific capacity, low density, and low electrochemical reduction potential. However, inhomogeneous lithium deposition on the Li surface will result in the formation of lithium dendrites and eventually puncture the separator and cause a short circuit. Herein, a functional metal-organic framework membrane with uniform unsaturated pyridine-nitrogen sites is synthesized via coating UiO-67-BPY (2,2 -bipyridine- 5,5 -dicarboxylic acid, named as BPY) on a commercial polypropylene (PP) separator. By replacing the benzene ring with a pyridine ring, the functionalization and porosity of MOF is fully utilized while maintaining the excellent porosity and pore size of MOF. The Li-ion transference number (tLi+) with the functional separator is 0.69 and the ionic conductivity is improved by order of magnitude compared to a plain PP separator. The N atom of the pyridine ring on the UiO-67-BPY has a strong electrostatic interaction force, and a weak coordination bond (N–Li bonding lattice) is formed between N and Li, which leads to an increase in the concentration of free lithium ions and makes their distribution more uniform. This allows lithium ions to migrate more smoothly, which is conducive to ionic conductivity and hinders dendrite formation.

Taste Mechanism of Umami Molecules from Fermented Broad Bean Paste Based on In Silico Analysis and Peptidomics.

In this study, in silico analysis and peptidomics were performed to examine the generation mechanism of the umami taste of fermented broad bean paste (FBBP). Based on the information from peptidomics, a total of 470 free peptides were identified from FBBP, most of which were increased after fermentation. Additionally, the increase of the content of umami peptides, organic acids, and amino acids during fermentation contributed to the perception of umami taste in FBBP. Molecule docking results inferred that these umami molecules were easy to connect with Ser, Glu, His, and Gln in the T1R3 subunit through hydrogen bonds and electrostatic interaction force. The binding sites His145, Gln389, and Glu301 particularly contributed to the formation of the ligand-receptor complexes. The aromatic interaction, hydrogen bond, hydrophilicity, and solvent-accessible surface (SAS) played key roles in the receptor-peptide interaction. Sensory evaluation and electronic tongue results showed that EDEDE, DLSESV, SNGDDE, DETL, CDLSD, and TDEE screened from FBBP had umami characteristics and umami-enhancing effects (umami threshold values ranging from 0.131 to 0.394 mmol/L). This work provides new insight into the rapid and efficient screening of novel umami peptides and a deeper understanding of the taste mechanisms of umami molecules from FBBP.

Physicochemical assessment of ammonium adsorption using a palm shell-based adsorbent activated with acetic acid: experimental and theoretical studies.

The adsorption of ammonium from water was studied on an activated carbon obtained using raw oil palm shell and activated with acetic acid. The performance of this adsorbent was tested at different operating conditions including the solution pH, adsorbent dosage, and initial ammonium concentration. Kinetic and equilibrium studies were carried out, and their results were analyzed with different models. For the adsorption kinetics, the pseudo-first order equation was the best model to correlate this system. Calculated adsorption rate constants ranged from 0.071 to 0.074 g/mg min. The ammonium removal was 70-80% at pH 6-8, and it was significantly affected by electrostatic interaction forces. Ammonium removal (%) increased with the adsorbent dosage, and neutral pH condition favored the adsorption of this pollutant. The best ammonium adsorption conditions were identified with a response surface methodology model where the maximum removal was 91.49% with 2.27 g/L of adsorbent at pH 8.11 for an initial ammonium concentration of 36.90 mg/L. The application of a physical monolayer model developed by statistical physics theory indicated that the removal mechanism of ammonium was multi-ionic and involved physical interactions with adsorption energy of 29 kJ/mol. This activated carbon treated with acetic acid is promising to depollute aqueous solutions containing ammonium.

Attractive and repulsive forces in a crystal of [Rb(18-crown-6)][SbCl6] under high pressure.

The compression behavior of [Rb(18-crown-6)][SbCl6] crystal under pressure up to 2.16 (3) GPa was investigated in a diamond anvil cell (DAC) using a mixture of pentane-isopentane (1:4) as the pressure-transmitting fluid. The compound crystallizes in trigonal space group R3 and no phase transition was observed in the indicated pressure range. The low value of pressure bulk modulus [9.1 (5) GPa] found in this crystal is a characteristic of soft materials with predominant dispersive and electrostatic interaction forces. The nonlinear relationship between unit-cell parameters under high pressure is attributed to the influence of reduced intermolecular H...Cl contacts under pressure over 0.73 GPa. It also explains the high compression efficiency of [Rb(18-crown-6)][SbCl6] crystals at relatively low pressures, resulting in a significant shift of the Rb atom to the center of the crown ether cavity. At pressures above 0.9 GPa, steric repulsion forces begin to play a remarkable role, since an increasing number of interatomic H...Cl and H...H contacts become shorter than the sum of their van der Waals (vdW) radii. Below 0.9 GPa, both unit-cell parameter dependences (P-a and P-c) exhibit hysteresis upon pressure release, demonstrating their influence on the disordered model of Rb atoms. The void reduction under pressure also demonstrates two linear sections with the inflection point at 0.9 GPa. Compression of the crystal is accompanied by a significant decrease in the volume of the voids, leading to the rapid approach of Rb atoms to the center of the crown ether cavity. For the Rb atom to penetrate into the center of the crown ether cavity in [Rb(18-crown-6)][SbCl6], it is necessary to apply a pressure of about 2.5 GPa to disrupt the balance of atomic forces in the crystal. This sample serves as a compression model demonstrating the influence of both attractive and repulsive forces on the change in unit-cell parameters under pressure.

Amidation-Reaction Strategy Constructs Versatile Mixed Matrix Composite Membranes towards Efficient Volatile Organic Compounds Adsorption and CO2 Separation.

Mixed matrix composite membranes (MMCMs) have shown advantages in reducing VOCs and CO2 emissions. Suitable composite layer, substrate, and good compatibility between the filler and the matrix in the composite layer are critical issues in designing MMCMs. This work develops a high-performance UiO-66-NA@PDMS/MCE for VOCs adsorption and CO2 permea-selectivity, based on a simple and facile fabrication of composite layer using amidation-reaction approach on the substrate. The composite layer shows a continuous morphological appearance without interface voids. This outstanding compatibility interaction between UiO-66-NH2 and PDMS is confirmed by molecular simulations. The Si─O functional group and UiO-66-NH2 in the layer leads to improved VOCs adsorption via active sites, skeleton interaction, electrostatic interaction, and van der Waals force. The layer and ─CONH─ also facilitate CO2 transport. The MMCMs show strong four VOCs adsorption and high CO2 permeance of 276.5 GPU with a selectivity of 36.2. The existence of VOCs in UiO-66-NA@PDMS/MCE increases the polarity and fine-tunes the pore size of UiO-66-NH2, improving the affinity towards CO2 and thus promoting the permea-selectivity for CO2, which is further verified by GCMC and EMD methods. This work is expected to offer a facile composite layer manufacturing method for MMCMs with high VOC adsorption and CO2 permea-selectivity.

The Reverse of Electrostatic Interaction Force for Ultrahigh‐Energy Al‐Ion batteries

AbstractThe two‐dimensional (2D) MXenes with sufficient interlayer spacing are promising cathode materials for aluminum‐ion batteries (AIBs), yet the electrostatic repulsion effect between the surface negative charges and the active anions (AlCl4−) hinders the intercalation of AlCl4− and is usually ignored. Here, we propose a charge regulation strategy for MXene cathodes to overcome this challenge. By doping N and Co, the zeta potential is gradually transformed from negative (Ti3C2Tx) to near‐neutral (Ti3CNTx), and finally positive (Ti3CNTx@Co). Therefore, the electrostatic repulsion force can be greatly weakened between Ti3CNTx and AlCl4−, or even formed a strong electrostatic attraction between Ti3CNTx@Co and AlCl4−, which can not only accommodate more AlCl4− ions in the Ti3CNTx@Co interlayers to increase the capacity, but also solve the stacking and expansion problems. As a result, the optimized Al‐MXene battery exhibits an ultrahigh capacity of up to 240 mAh g−1 (2–4 times the capacity of graphite cathode, 60–120 mAh g−1) and a potential ultrahigh energy density (432 Wh kg−1, 2–4 times the value of graphite, 110–220 Wh kg−1) based on the mass of cathode materials, comparable to LiFePO4‐based lithium‐ion batteries (350–450 Wh kg−1, based on the mass of LiFePO4).