Van Der Waals Interactions Research Articles

Computational biophysical characterization of the effect of gatekeeper mutations on the binding of ponatinib to the FGFR kinase

Fibroblast Growth Factor Receptor (FGFR) is connected to numerous downstream signalling cascades regulating cellular behavior. Any dysregulation leads to a plethora of illnesses, including cancer. Therapeutics are available, but drug resistance driven by gatekeeper mutation impedes the treatment. Ponatinib is an FDA-approved drug against BCR-ABL kinase and has shown effective results against FGFR-mediated carcinogenesis. Herein, we undertake molecular dynamics simulation-based analysis on ponatinib against all the FGFR isoforms having Val to Met gatekeeper mutations. The results suggest that ponatinib is a potent and selective inhibitor for FGFR1, FGFR2, and FGFR4 gatekeeper mutations. The extensive electrostatic and van der Waals interaction network accounts for its high potency. The FGFR3_VM mutation has shown resistance towards ponatinib, which is supported by their lesser binding affinity than wild-type complexes. The disengaged molecular brake and engaged hydrophobic spine were believed to be the driving factors for weak protein-ligand interaction. Taken together, the inhibitory and structural characteristics exhibited by ponatinib may aid in thwarting resistance based on Val-to-Met gatekeeper mutations at an earlier stage of treatment and advance the design and development of other inhibitors targeted at FGFRs harboring gatekeeper mutations.

The In Vitro and In Silico Study of α-glucosidase Inhibition by Kombucha Derived from Syzygium polyanthum (Wight) Walp. Leaves

Kombucha is a fermented tea drink using a symbiotic culture of bacteria and yeast. This drink has been widely used to maintain blood sugar levels. Meanwhile, leaf boiled water of Syzygium polyanthum (Wight) Walp. has been used as an alternative medicine for diabetes mellitus in Indonesia. If this herb is made into kombucha, it may have higher antihyperglycemic activity than kombucha from tea leaves. However, there are no scientific reports of antihyperglycemic activity from S. polyanthum leaf kombucha by inhibiting alpha-glucosidase. This study aims to determine the activity and kinetics inhibition of S. polyanthum leaves kombucha against α-glucosidase. Samples were prepared at varying concentrations (12.5, 25, 37.5, 50 g/L), while phytochemical components in the products were identified, and the inhibitory activity as well as kinetics were comprehensively analyzed. In silico evaluations were conducted to further explore the inhibitory activity. The results showed that the products contained secondary metabolites such as flavonoids, saponins, and tannins. The inhibitory activity against α-glucosidase ranged from 81.05 to 89.41%. The inhibition mechanism was identified as uncompetitive, with a Michaelis-Menten constant (KM) of 0.1357 mM and a vmax value of 27.7008 U/ml minute. Several metabolites showed promising inhibition potential due to their strong binding interactions with α-glucosidase, including hydrogen bonding (H-bond), hydrophobic interactions, van der Waals forces, and electrostatic forces. Additionally, two metabolites, farnesol and α-pinene, were found to interact with other human proteins. These observations showed the potential of S. polyanthum leaves kombucha as a health-promoting beverage that might aid blood sugar control in diabetic individuals.

PH-Dependent interactions between β-casein and blueberry anthocyanins based on typical thermal processing conditions: Stability, structural characterization, and binding mechanisms

The color and structural stability of blueberry anthocyanins (BAs) are significantly affected by pH changes during processing. In this study, we present the potential effects of the thermal stability, structural characterization, and binding mechanism of BAs with β-casein (β-CN) at pH 2, 4, and 6 for the first time. The pH was found significantly affect the ability of β-CN to protect BAs from thermal, vitamin C, and sucrose induced degradation. Scanning electron microscopy (SEM) resolved the microstructural differences of β-CN-BAs at varying pH values. Multispectral analysis showed that as pH increases, the electrostatic interaction between β-CN and the major monomer of anthocyanins Cyanidin-3-O-glucoside (C3G) are replaced by hydrogen bonding and van der Waals forces, and then electrostatic interactions are again the dominant force. In vitro gastrointestinal digestion confirmed that the protein stabilized C3G under varying pH conditions. Nuclear magnetic resonance (NMR) spectroscopy reveals the connection between the multiple equilibrium forms of C3G (hemiketal, cis-chalcone, and trans-chalcone) and β-CN on the formation of complexes between multiple equilibrium forms to specifically elucidate the mechanism of its stabilizing effect. Molecular docking simulation revealed the significance of electrostatic interaction and hydrogen bonding, where the highest binding match was achieved at pH 2, with a minimum binding energy. These interactions can effectively promote stable complexation of β-CN with C3G. These findings have practical implications for protein regulation of the relationship between the equilibrium forms of different anthocyanins and can guide the stabilization of anthocyanin-rich products.

Fluorophilic Sigma(σ)‐Lock Self‐Healable Copolymers

AbstractAlthough F‐Containing molecules and macromolecules are often used in molecular biology to increase the binding with Lewis acidic groups by introducing favorable C−F dipoles, there is virtually no experimental evidence and limited understanding of the nature of these interactions, especially their role in synthetic polymeric materials. These studies elucidate the molecular origin of inter‐ and intra‐Chain interactions responsible for self‐healing of F‐Containing copolymers composed of pentafluorostyrene and n‐butyl acrylate units (p(PFS/nBA). Guided by dynamic surface oscillating force (SOF) and spectroscopic measurements supported by molecular dynamics (MD) simulations, these studies show that the reformation of σ‐σ orbitals in −C−F of PFS and CH3CH2− of nBA units enables the recovery of entropic energy via fluorophilic‐σ‐lock van der Waals forces when PFS/nBA molar ratios are ~50/50. The strength of these interactions determined experimentally for self‐healable PFS/nBA compositions is in the order ~0.3 kcal/mol which primarily comes from fluorophilic‐σ‐lock (~70 %) contributions. These interactions are significantly diminished for non‐self‐healable counterparts. Strongly polarized −C−F σ orbitals create lateral dipolar forces enhancing the affinity towards −C−H orbitals, facilitating energetically favorable interactions. Entropic recovery driven by non‐Covalent bonding offers a valuable tool in designing materials with unique functionalities, particularly self‐healable batteries and energy storage devices.

Engineered PEI-WS2 nanocomposite membranes for highly efficient pervaporation of water/isopropanol mixture

In this study, we present a novel approach to enhance pervaporation (PV) separation processes by addressing the challenge of membrane swelling due to organic aqueous solutions in polyelectrolyte composite systems. By integrating tungsten disulfide (WS2) and polyethyleneimine (PEI) into the membrane matrix, we synthesized a series of polyelectrolyte complex composite membranes on a modified polyacrylonitrile substrate. The unique interplay of WS2′s van der Waals forces and PEI's cationic attributes imparts enhanced structural stability and swelling resistance, culminating in a significant elevation of separation efficiency. The morphological and physicochemical properties of the membranes were meticulously characterized through scanning electron microscopy, atomic force microscopy, water contact angle measurements, and attenuated total reflection fourier transform infrared spectroscopy. In our pervaporation experiments, these membranes exhibited exceptional proficiency, separating a 70 wt% isopropyl alcohol aqueous solution under ambient conditions (25 °C, pH 7) with a fine-tuned PEI-WS2 ratio and concentration. The membranes achieved a permeation flux of 1380.86 g·m−2·h−1 and delivered a permeate with a water concentration of 99.71 wt%, underscoring their suitability for high-purity separations. Moreover, the membranes displayed consistent performance over extended operational periods, underscoring their robustness and durability. These results not only reinforce the potential of these membranes for industrial-scale separation tasks but also set the stage for further exploration into polyelectrolyte complex composites within the field of membrane science.

Study of the mechanism of non-covalent interactions between chlorogenic acid and soy protein isolate: Multi-spectroscopic, in vitro, and computational docking analyses

This study investigated the interaction mechanism between chlorogenic acid (CA) and soy protein isolate (SPI) through multi-spectroscopic and computational docking and analyzed the changes in its functional properties. The results showed that the interaction of CA with SPI changed its UV and fluorescence absorption, and the fluorescence quenching mechanism was static quenching. At the same time, the secondary structure of the protein was altered, with a reduction in α-helix, β-sheet and β-turn. Computer docking analysis showed that CA binds to SPI through hydrophobic interactions, van der Waals forces, and hydrogen bonding to form a more compact complex. In addition, the dose-dependent enhancement of CA improved the functional properties of the complexes, including foaming, emulsification, and antioxidant properties. This study systematically investigated the mechanism of interaction between CA and SPI, which supports further research on food complex systems containing CA and SPI, as well as the application of the complex.

Effects of expanded graphite’s structural and elemental characteristics on its oil and heavy metal sorption properties

Expanded graphite has promising potential environmental applications due to its porous structure and oleophilic nature, which allow it to absorb large quantities of oil. The material is produced by intercalating graphite and applying heat to convert the intercalant into gas to cause expansion between the layers in the graphite. Using different intercalants and temperature conditions results in varying properties of expanded graphite. This work has proven that the sorption properties of commercial expanded graphite differ significantly due to the material’s structural and elemental characteristics, which can be attributed to the intercalation method. This resulted in various degrees of exfoliation of the graphite and possible functionalisation of the graphene sheets within the structure. This affected the material's sorption capacity and its affinity for heavy metal sorption by incorporating selectivity towards the sorption of certain metals. It was found that sample EG3, which underwent a less harsh expansion, exhibited lower porosity than EG1, and thus, the sample absorbed less oil at 37.29 g/g compared to the more expanded samples EG1 and EG2 with 55.16 g/g and 48.82 g/g, respectively. However, it was able to entrap a wider variety of metal particles compared to EG1 and EG2, possibly due to its smaller cavities allowing for a capillary effect between the graphene sheets and greater Van der Waals forces. A second possibility is that ionic or coordination complexes could form with certain metals due to the possible functionalisation of the expanded graphite during the intercalation process. This would be in addition to coordination between the metals and expanded graphite carbon atoms. The findings suggest that there is evidence of functionalisation as determined by XRD and elemental analyses. However, further investigation is necessary to confirm this hypothesis. The findings in this work suggest that the first mechanism of sorption was more likely to be related to the degree of expansion of the expanded graphite. Various metals are present in used oil, and their removal can be challenging. Some metals in oil are not considered heavy since they have a relatively low density but can be associated with heavy metals in terms of toxicity.

Effects of reduced graphene oxide nanomaterials on transformation of 14C-triclosan in soils

Increasing use and release of graphene nanomaterials and pharmaceutical and personal care products (PPCPs) in soil environment have polluted the environment and posed high ecological risks. However, little is understood about the interactive effects and mechanism of graphene on the behaviors of PPCPs in soil. In the present study, the effects of reduced graphene oxide nanomaterials (RGO) on the fate of triclosan in two typical soils (S1: silty loam; S2: silty clay loam) were investigated with 14C-triclosan, high-resolution mass spectrometry, scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), density functional theory (DFT) calculations, and microbial community structure analysis. The results showed that RGO prolonged the half-life of triclosan by 23.6–51.3 %, but delayed the formation of transformed products such as methyl triclosan and dechlorinated dimer of triclosan in the two typical soils. Mineralization of triclosan to 14CO2 was inhibited by 48.2–79.3 % in 500 mg kg−1 RGO in comparison with that in the control, whereas the bound residue was 54.2–56.4 % greater than the control. RGO also reduced the relative abundances of triclosan-degrading bacteria (Pseudomonas and Sphingomonas) in soils. Compared to silty loam, RGO more effectively inhibited triclosan degradation in silty clay loam. Furthermore, the DFT calculations suggested a strong association of the adsorption of triclosan on RGO with the van der Waals forces and π-π interactions. These results revealed that RGO inhibited the transformation of 14C-triclosan in soil through strong adsorption and triclosan-degrading bacteria inhibition in soils. Therefore, the presence of RGO may potentially enhance persistence of triclosan in soil. Overall, our study provides valuable insights into the risk assessment of triclosan in the presence of GNs in soil environment.

Wetting Effect Induced Depletion and Adsorption Layers: Diffuse Interface Perspective.

When a multi-component fluid contacts arigid solid substrate, the van der Waals interaction between fluids and substrate induces a depletion/adsorption layer depending on the intrinsic wettability of the system. In this study, we investigate the depletion/adsorption behaviors of A-B fluid system. We derive analytical expressions for the equilibrium layer thickness and the equilibrium composition distribution near the solid wall, based on the theories of de Gennes and Cahn. Our derivation is verified through phase-field simulations, wherein the substrate wettability, A-B interfacial tension, and temperature are systematically varied. Our findings underscore two pivotal mechanisms governing the equilibrium layer thickness. With an increase in the wall free energy, the substrate wettability dominates the layer formation, aligning with de Gennes' theory. When the interfacial tension increases, or temperature rises, the layer formation is determined by the A-B interactions, obeying Cahn's theory. Additionally, we extend our study to non-equilibrium systems where the initial composition deviates from the binodal line. Notably, macroscopic depletion/adsorption layers form on the substrate, which are significantly thicker than the equilibrium microscopic layers. This macroscopic layer formation is attributed to the interplay of phase separation and Ostwald ripening. We anticipate that the present finding could deepen our knowledge on the depletion/adsorption behaviors of immiscible fluids.

MXene/Nitrogen-Doped Carbon Nanosheet Scaffold Electrode toward High-Performance Solid-State Zinc Ion Supercapacitor.

While MXene is widely used as an electrode material for supercapacitor, the intrinsic limitation of stacking caused by the interlayer van der Waals forces has yet to be overcome. In this work, a strategy is proposed to fabricate a composite scaffold electrode (MCN) by intercalating MXene with highly nitrogen-doped carbon nanosheets (CN). The 2D structured CN, thermally converted and pickling from Zn-hexamine (Zn-HMT), serves as a spacer that effectively prevents the stacking of MXene and contributes to a hierarchically scaffolded structure, which is conducive to ion movement; meanwhile, the high nitrogen-doping of CN tunes the electronic structure of MCN to facilitate charge transfer and providing additional pseudocapacitance. As a result, the MCN50 composite electrode achieves a high specific capacitance of 418.4 Fg-1 at 1 Ag-1. The assembled symmetric supercapacitor delivers a corresponding power density of 1658.9 Wkg-1 and an energy density of 30.8 Whkg-1. The all-solid-state zinc ion supercapacitor demonstrates a superior energy density of 68.4 Whkg-1 and a power density of 403.5 Wkg-1 and shows a high capacitance retention of 93% after 8000 charge-discharge cycles. This study sheds a new light on the design and development of novel MXene-based composite electrodes for high performance all-solid-state zinc ion supercapacitor.

Theoretical predictions of properties and adsorption behaviour of a superheavy element Ts and its lighter homolog At, and of their various gas-phase compounds, on hydroxylated quartz surfaces from periodic DFT calculations

Adsorption energies, E ads, of a superheavy element Ts and its lighter homolog At, as well as of their various oxides, hydrides, and (oxy)hydroxides on hydroxylated quartz surfaces are calculated using a periodic density functional theory implemented in the AMS BAND software. It was shown that elemental At and Ts should be the most volatile over the quartz surfaces out of all the considered species, with E ads of the order of van der Waals bond energies, ∼25 kJ/mol. Hydride and hydroxide of At and Ts should be slightly less volatile than the elements with ∼20 kJ/mol larger E ads values. Oxides and oxyhydroxides of these elements should be the least volatile. All the compounds of Ts should be less volatile than the respective At ones. The differences in the E ads values between the Ts species should also be larger than those between the related At compounds, so that one should be able to differentiate between them more easily.

Construction of a three-dimensional energy-stabilized macromolecular model of Daliuta coal and investigation of the influence of weak interactions on wettability: Dust pollution prevention and control

Understanding the molecular structure of coal is crucial for gaining insights into the wetting mechanism of coal dust, thus enabling the precise and efficient management of coal dust. After determining the structural information and functional group composition of the coal samples, we continuously adjusted the positions of the groups and the linkages to construct a planar molecular model. Our findings indicate that the Daliuta coal molecule is primarily composed of aromatic carbons, with aliphatic carbons existing in branched form or linked to aromatic rings. The main type of oxygen is carbonyl oxygen, and the molecular formula for Daliuta coal was determined to be C286H263N3O50S. We optimized and annealed the molecular model geometrically, causing the aliphatic bonds in the molecule to undergo numerous deflections and folds, whereas the aromatic structure tended to arrange itself in a laminar pattern due to van der Waals interactions. Given the large number of oxygen-containing functional groups, the electrostatic potential energy contributes significantly to the non-bonding energy, ensuring the stability of the structure. Finally, we obtained the global energy-minimum three-dimensional macromolecular model, establishing the polymerized structure of the coal molecule with a density of 1180 kg/m3. Additionally, we quantitatively analyzed the region of weak interactions between the electrostatic potential on the surface of the coal at the molecular and intramolecular levels. This analysis helped elucidate potential adsorption sites, providing theoretical guidance for modeling the targeted preparation of a spraying dust-reducing agent suitable for this type of coal.

Research on optimizing ultrasonic frequencies for efficient single-walled carbon nanotube dispersion in water using a focused ultrasonic system

Single-walled carbon nanotubes (SWCNTs) can be applied in a wide range of fields owing to their excellent mechanical rigidity, electrical conductivity, and thermal conductivity. However, their application is limited because of their strong van der Waals forces and poor dispersion owing to their hydrophobic properties. To address this problem, ultrasonic dispersion technology has been used in the industry. However, very few studies have investigated the surface damage or effectiveness of the surfactants of SWCNTs with a focus on the frequencies of specific ultrasonic equipment. In this study, the dispersibility of SWCNTs at frequencies of 270, 400, and 700 kHz was investigated using a new focused ultrasonic instrument. The dispersion stability of the samples was analyzed according to each frequency, and the SWCNT surface was studied in detail using field-emission transmission electron microscopy, Raman spectroscopy, and X-ray photoelectron spectroscopy. The adsorption of the polymeric surfactant to the SWCNT was most observed at 270 kHz, and the dispersion stability after processing at this frequency was better than that of the other samples. Therefore, the frequency of the ultrasonic intensity has a direct effect on the surface modification of SWCNTs.

Oxygen intercalation in 2D layered PtSe2 for tunable bandgap infrared photoelectric materials

Infrared materials play a pivotal role in driving societal advancement across various domains. Bilayer PtSe2 with bandgap of 0.2 eV is an ideal material for infrared applications. However, the inherent limitation of the untunable bandgap in bilayer PtSe2 restricts its utility, particularly in the context of state-of-the-art two-color infrared detectors. Therefore, by introduction of quantum confinement effect, PtSe2[O]y superlattice was constructed via intercalating O atoms into interlayer space of PtSe2, and kinetic stability was confirmed by ab initio molecular dynamics. Considering van der Waals interactions of interlayer, PtSe2[O]y superlattice can be exfoliated into few-layer PtSe2[O]y. By employing density functional theory, optical and electrical properties of PtSe2[O]y superlattice and few-layer PtSe2[O]y were calculated. Tunable bandgaps were achieved by manipulating the O composition y, ranging from 0 eV to 0.21 eV (covering wavelengths > 5.9 μm) for the PtSe2[O]y superlattice and from 1.12 eV to 0.15 eV (covering wavelengths from 1.1 μm to 8.3 μm) for monolayer PtSe2[O]y. Considering the continuously tunable bandgap covering from near-infrared to mid-infrared absorption spectrum, PtSe2[O]y could be a promising candidate with a wide-application in the field of infrared photoelectric materials.

Investigating the catalytic mechanisms of key metabolic enzymes

The fundamental idea behind enzyme catalysis is to increase the pace of a process by lowering its activation energy. Enzymes accomplish this by creating an enzyme-substrate complex by binding substrates in their active areas. This binding stabilizes the reaction's transition state through a variety of non-covalent interactions, including hydrogen bonds, ionic interactions, and Van der Waals forces. The energy barrier that needs to be broken through for the reaction to continue is lowered by this stabilization.

Molecular docking and molecular dynamics simulation of wheat gluten-derived antioxidant peptides acting through the Keap1-Nrf2 pathway.

In our previous study, we successfully identified five peptides from wheat gluten: Ala-Pro-Ser-Tyr (APSY), Leu-Tyr (LY), Pro-Tyr (PY), Arg-Gly-Gly-Tyr (RGGY) and Tyr-Gln (YQ). Molecular docking and molecular dynamics simulation methods were employed to investigate the interaction between these antioxidant peptides and the Kelch-like ECH-associated protein 1 (Keap1 protein), revealing the molecular mechanism of their non-competitive binding. In addition, the total antioxidant capacity of the five peptides was determined using the 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) method. The affinities of APSY, LY, PY, RGGY and YQ were -8.9, -8.3, -8.5, -9.1 and - 7.9 kcal mol-1, respectively. The five peptides effectively bound to Keap1 protein through hydrogen, π-σ, π-alkyl and alkyl interactions. Significant roles were observed for the P1 pocket residue ARG-415 and the P3 pocket residue ALA-556 in the interactions of the Keap1-peptide complexes. Molecular dynamics simulations further elucidated the dynamic process of peptide binding to the Keap1 protein. All five peptides formed stable complexes with Keap1 protein, with van der Waals forces playing crucial roles in these complex systems, indicative of the peptides' strong binding ability to Keap1 protein. The van der Waals forces were -178.74, -123.11, -134.36, -132.59, and -121.44 kJ mol-1 for the Keap1-APSY, Keap1-LY, Keap1-PY, Keap1-RGGY and Keap1-YQ complexes, respectively. These peptides exhibited excellent antioxidant effects. Among them, the YQ peptide exhibited the highest total antioxidant capacity, with an activity value of 1.18 ± 0.06 mmol Trolox equivalent (TE) L-1 at a concentration of 0.10 mg mL-1. The RGGY, PY, LY and APSY peptides followed in descending order, with activity values of 0.91 ± 0.05, 0.72 ± 0.06, 0.62 ± 0.04 and 0.60 ± 0.05 mmol TE L-1, respectively. These results unveiled the molecular mechanism by which the five antioxidant peptides act on active pockets through the Keap1-Nrf2 signaling pathway, providing a theoretical basis for the development of antioxidants. © 2024 Society of Chemical Industry.

Decorating the Node of a Zirconium-Based Metal-Organic Framework to Tune Adsorption Behavior and Surface Permeation.

Surface barriers are commonly observed in nanoporous materials. Although researchers have explored methods to repair defects or create flawless crystals to mitigate surface barriers, these approaches may not always be practical or readily achievable in targeted metal-organic frameworks (MOFs). In our study, we propose an alternative approach focusing on the introduction of diverse ligands onto a MOF-808 node to finely adjust its adsorption and mass transport characteristics. Significantly, our findings indicate that while adsorption curves can be inferred based on the MOF's chemical composition and the probing molecule, surface permeabilities exhibit variations dependent on the specific probe utilized and the incorporated ligand. Our investigation, considering van der Waals forces exclusively between the adsorbate (e.g., n-hexane, propane, and benzene) and the adsorbent, revealed that augmenting these interactions can indeed improve surface permeation to a certain extent. Conversely, strong adsorption resulting from hydrogen bonding interactions, particularly with water in modified MOFs, led to compromised permeation within the MOF crystals. These outcomes provide valuable insights for the porous materials community and offer guidance in the development of adsorbents with enhanced affinity and superior mass transport properties for gases and vapors.

Recent development of substrates for immobilization of bimetallic nanoparticles for wastewater treatment: a review.

Bimetallic nanoparticles (BMNPs) have gained considerable attention due to their remarkable catalytic properties, making them invaluable in wastewater treatment applications. One of these challenges lies in the propensity of BMNPs to aggregate due to Van der Waals interactions, which can reduce their overall performance. Additionally, retrieving exhausted NPs from the treated solution for subsequent reuse remains a significant hurdle. Moreover, the leaching of NPs into the discharged wastewater can have harmful effects on humans as well as aquatic life. To overcome these issues, various substrates have been researched to maximize the efficiency and stability of the NPs. This review paper delves into the pivotal role of various substrates in immobilizing BMNPs, providing a comprehensive analysis of their performances, advantages, and drawbacks. The substrates encompass a diverse range of materials, including organic, inorganic, organic-inorganic, beads, fibers, and membranes. Each substrate type offers unique attributes, influencing the stability, efficiency, and recyclability of BMNPs. This review paper aims to provide an up-to-date and detailed analysis and comparison of the substrates used for the immobilization of BMNPs. This work further reviews the underlying mechanisms of the composites involved in treating pollutants from wastewater and how these mechanisms are enhanced by the synergistic effects produced by the substrate and BMNPs. Furthermore, the reusability and sustainability of these composites are discussed. Also, high-performing substrates are highlighted to give direction to future research focusing on the immobilization of BMNPs in the application of wastewater treatment.

Flame‐Retardant, Self‐Purging, High‐Voltage Electrolyte for Safe and Long‐Cycling Sodium Metal Batteries

AbstractSodium metal batteries (SMBs) remain greatly challenging in safety and stability. Herein, a flame‐retardant s designed, self‐purging high‐voltage electrolyte is designed to stabilize SMBs with the use of ethoxy (pentafluoro) cyclotriphosphazene (PFPN) as the electrolyte additive. PFPN can participate in the shell structure of solvation through stronger van der Waals force to form Na3N, NaF‐rich solid/cathode electrolyte interphase (SEI/CEI) with electronic insulation and fast ion transport. Moreover, harmful impurity (PF5) also can be scavenged by van der Waals force to avoid HF production, which helps to stabilize the electrode interface. Additionally, combustion radicals (H, HO) can be cleared by van der Waals force between radical (RPO) formed by breaking with PFPN and combustion radicals for flame‐retardation purpose. As expected, the high‐voltage Na||Na3V2(PO4)2O2F battery with modified electrolyte can deliver reservation of 92.4%, CE of 99.71% after 2000 cycles, and simultaneously possess excellent high‐rate and fast charging/slow discharging performance.

Precision engineering of nano-assemblies in superfluid helium by the use of van der Waals forces

The ability to precisely engineer nanostructures underpins a wide range of applications in areas such as electronics, optics, and biomedical sciences. Here we present a novel approach for the growth of nanoparticle assemblies that leverages the unique properties of superfluid helium. Unlike viscous solvents at or near room temperature, superfluid helium provides an unperturbed and cold environment in which weak van der Waals interactions between molecular templates and metal atoms become significant and can define the spatial arrangement of nanoparticles. To demonstrate this concept, diol and porphyrin-based molecules are employed as templates to grow gold nanoparticle assemblies in superfluid helium droplets. After soft-landing on a solid surface to remove the helium, transmission electron microscopy (TEM) imaging shows the growth of gold nanoparticles at specific binding sites within the molecular templates where the interaction between gold atoms and the molecular template is at its strongest.