Electrostatic Method Research Articles

Preparation of eGaIn NDs/TPU Composites for X-ray Radiation Shielding Based on Electrostatic Spinning Technology.

Thermoplastic polyurethane (TPU) composites with eutectic gallium (Ga) and indium (In) (eGaIn) fillings of 0 wt%-75 wt% were prepared using the electrostatic spinning method. Field emission scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier-transform infrared (FTIR) spectroscopy were used to characterize the eGaIn NDs/TPU composites. To evaluate their X-ray shielding properties, Phy-X/PSD and WinXCom were employed to calculate the mass attenuation coefficients, linear attenuation coefficients, half-value layers, tenth value layers, mean free paths, and adequate atomic numbers of the eGaIn NDs/TPU composites. The SEM results indicated that the eGaIn nanodroplets were evenly distributed throughout the TPU fibers, and the flowable eGaIn was well-suited for interfacial compatibility with the TPU. A comparison of the eGaIn NDs/TPU composites with different content levels showed that the composite with 75 wt% eGaIn had the highest μm at all the evaluated energies, indicating a superior ability to attenuate X-rays. This non-toxic, lightweight, and flexible composite is a potential material for shielding against medical diagnostic X-rays.

Assembling flower-like MgAl-LDH nanospheres and g-C3N4 nanosheets for high efficiency removal of methyl orange

Flower-like Mg–Al–CO3 layered double hydroxide (MgAl-LDH) nanospheres with specific surface area of 221.95 m2/g were synthesized by modified aqueous miscible organic solvent treatment method. Via the electrostatic self-assembly method, MgAl-LDH and g-C3N4 nanosheets (CNNS), with the mass ratio of 1:10, 3:10, 5:10, 7:10, and 10:10, respectively, were assembled to prepare MgAl-LDH/g-C3N4 composites (MCN-X, X = 1, 3, 5, 7, and 10). The mass ratio of MgAl-LDH to g-C3N4 nanosheets affected the microstructure, optical and photo-electrochemical properties, and the removal efficiency toward methyl orange (MO), of MCN-X composites. The adsorption and photocatalytic degradation performance for MO by all MCN-X composites were better than those by pure g-C3N4 nanosheets. With the increasing of MgAl-LDH content, the adsorption rate and removal rate of MO by MCN-X composites increased firstly and then decreased gradually. The optimum performance was achieved by MCN-5, which removed 93.58 % of MO molecules after 30 min of dark adsorption and 120 min of photocatalytic degradation, and its pseudo-first-order reaction rate constants (k) value (0.0177 min−1) was 3.4 times that of CNNS. Reasons for these results were the enhanced specific surface area, the narrowed band gap, the inhibited recombination and the improved separation and migration of photo-generated carriers, as well as the excellent adsorption ability of MCN-5. This work provides a feasible strategy for synthesizing high performance MgAl-LDH/g-C3N4 composite photocatalyst.

Dual-Sensitive Carbohydrate-Based Nanosystem for Targeted Drug Delivery to Potentiate the Therapeutic Efficacy of Ulcerative Colitis.

Conventional oral formulations for inflammatory bowel disease (IBD) treatment are less than satisfactory, due to the poor controllability of drug release and lack of specificity to the inflammation sites in the gastrointestinal (GI) tract. To overcome these limitations, we developed a multiple carbohydrate-based nanosystem with pH/ROS dual responsibility and charge-mediated targeting ability for IBD-specific drug delivery. In view of the overproduction of ROS and overexpression of cationic proteins in the inflammatory colon, the designed nanosystem was composed of oxidation-sensitive cyclodextrin (OX-CD), chitosan (CS) and pectin (AHP). OX-CD was utilized to load dexamethasone (DM) by the solvent evaporation method. CS and AHP with opposite charges were sequentially coated onto OX-CD to generate the nanosystems by the electrostatic self-assembly method. The physicochemical properties, stability, dual-sensitive drug release behavior, cytotoxicity, cellular uptake and anti-inflammatory activity were investigated in vitro. In vivo bio-distribution and therapeutic efficacy of the nanosystem were further evaluated in the ulcerative colitis (UC) mice. The obtained AHP/CS/OX-CD-DM nanosystem (ACOC-DM) could maintain stability under the GI pH environments, and release drug in the inflammatory colon with pH/ROS sensitivity. Dual polysaccharide-coated ACOC-DM exhibited higher cellular uptake and anti-inflammatory efficacy in macrophages than single polysaccharide-coated CS/OX-CD-DM nanosystem (COC-DM). Orally administrated ACOC-DM could enhance inflammation targeting ability and therapeutic efficacy of DM in the UC mice. This carbohydrate-based nanosystem with pH/ROS dual sensitivity and inflammation targeting capacity may serve as a safe and versatile nanoplatform for IBD therapy.

Enhanced photocatalytic CO2 conversion over 0D/2D CsPbBr3/BiOCl S-scheme heterojunction via boosting charge separation.

The stable contact of heterogeneous interfaces and the substantial exposure of active sites are crucial for enhancing the photocatalytic performance of semiconductor catalysts. However, most reported two-dimensional (2D)/2D CsPbBr3 and BiOCl heterostructures are fabricated using electrostatic self-assembly methods, which exhibit significant deficiencies in precise interface quality control and effective active site exposure. In this study, we fabricate a zero-dimensional (0D)/2D CsPbBr3/BiOCl heterojunction via a two-step calcination method, achieving an efficient direct S-scheme configuration. Optimizing interfacial contact and band alignment between CsPbBr3 quantum dots and BiOCl nanosheets enhances cross-plane charge transfer, promoting superior charge separation. This 0D/2D CsPbBr3/BiOCl heterojunction exhibits enhanced carrier mobility and high conversion rates without cocatalysts or sacrificial agents. The mechanism underlying the accelerated S-scheme charge transfer is comprehensively elucidated through a combination of analytical techniques and density functional theory (DFT) calculations. This study offers a novel approach for managing charge carrier segregation and mobility in CO2 reduction photocatalysts.

Self-assembled hollow CuS@AuNRs/PDA nanohybrids with synergistically enhanced photothermal efficiency.

The design of multifunctional nanocarriers with enhanced photothermal efficiency is of great significance for the photothermal therapy of cancer. In this study, hollow CuS@gold nanorods/polydopamine (HCuS@AuNRs/PDA) nanohybrids with synergistically enhanced photothermal efficiency were prepared by electrostatic self-assembly method. The high photothermal conversion efficiency of HCuS@AuNRs (55.88%) is attributed to the interfacial electron transfer between CuS and AuNRs, as well as the increase in free charge carrier concentration. The excellent adhesion performance and strong negative charge of PDA ensure a high doxorubicin hydrochloride (DOX) loading efficiency of 96.08% for HCuS@AuNRs/PDA. In addition, HCuS@AuNRs/PDA reveals outstanding NIR/pH dual-responsive drug release properties owing to the weakened interaction between PDA and DOX in acidic media and the distinct NIR responsiveness of HCuS@AuNRs. In vitro cell viability results confirm that HCuS@AuNRs/PDA could efficiently kill tumor cells under the dual effect of acidic media and NIR laser. This study presents a novel nanocarrier with synergistically enhanced NIR photothermal responsiveness and high drug loading capacity, which provides a versatile platform in intelligent drug release and photothermal therapy.

Efficient detection of carbendazim using an electrochemical sensor for a novel NiFeLDH@HsGY-NH2/MWCNTs heterostructure with lattice-strain.

Carbendazim (CBZ) is widely used for crop protection and its residues threaten human health and the environment. Therefore, developing an effective electrocatalyst is important for the extremely sensitive detection of CBZ. Lattice-strain engineering is an effective strategy to change its electronic structure and ultimately optimize the catalytic performance of materials, which can be used as a modification method to improve the detection performance of electrochemical sensors. Herein, a NiFeLDH@HsGY-NH2/MWCNTs heterojunction with strain effect is prepared by the electrostatic self-assembly method. The structure, morphology, composition, crystallinity and electrochemical performance of NiFeLDH@HsGY-NH2/MWCNTs are analyzed using various instrumental techniques, in which geometric phase analysis (GPA) and X-ray diffraction (XRD) images confirm the lattice-strain generated in NiFeLDH@HsGY-NH2/MWCNTs. The results indicate that the prepared electrochemical sensor exhibited an excellent response for carbendazim (CBZ) in the linear range of 0.05-50.00 μM with a detection limit of 10.00 nM (S/N = 3) under the optimal detection conditions. By analyzing the reasons for the improvement of the catalytic performance of the composite material, it is found that the composite of MWCNTs not only improves the conductivity of NiFeLDH but also regulates the electronic structure of metal atoms through double effects. This study provides new insights into the design of efficient and low-cost catalysts to facilitate electrochemical sensor applications.

Exploration of novel dual-emission NL-CDs/Cu–Cy–I ratio fluorescent probe for the sensitive detection of amoxicillin

A dual-emission ratio fluorescence probe (NL-CDs/Cu–Cy–I) was fabricated via an electrostatic self-assembly method.

Electrostatic Boundary Integral Method for 3D Structures in a Layered Conducting Medium

Electrostatic Boundary Integral Method for 3D Structures in a Layered Conducting Medium

SiO2/Co encapsulated in N-doped carbon nanofibers as anode materials for lithium-ion batteries

To address the issues of poor electrical conductivity and volume expansion of SiO2, the composite SiO2/Co encapsulated in N-doped Carbon nanofibers is prepared in situ using an electrostatic spinning method followed a high-temperature treatment. Co nanoparticles exist as an elementary substance in the composite and improve the electrical conductivity of the composite, resulting in enhanced electrochemical performance. In addition, the N-doped carbon nanofibers wrap around the outside of SiO2/Co to form a conductive network, which improves the conductivity of the composite and alleviates the volumetric effects during the charge-discharge process. As expected, the prepared SiO2/Co@N-doped carbon nanofibers exhibit excellent rate performance, which can provide a very high discharge specific capacity of 1276 mA h g−1 and 493 mA h g−1 at current densities of 0.1 A g−1 and 2 A g−1, respectively. The composite also has a long cycle life, with a reversible discharge capacity of 659 mA h g−1 at 0.5 A g−1 after 400 cycles, and 552 mA h g−1 at 1 A g−1 after 1000 cycles. Furthermore, a full-cell LiFePO4||SiO2|Co@N-doped carbon nanofibers can release a reversible capacity of 119 mA h g−1 at 0.1C.

PROSPECTS FOR THE INTEGRATION OF QUARTZ-FELDSPAR CONCENTRATE OBTAINED FROM KAOLIN ENRICHMENT INTO CERAMIC PRODUCTION PROCESSES

ABSTRACT. The paper examin es the potential use of quartz feldspar concentrate obtained as a result of kaolin enrichment to meet the growing demand for quartz feldspar materials, which are essential components in the production of ceramic tiles, sanitary ceramics and other products. The research methodology includes laboratory tests of the chemical composition of kaolin enrichment waste and analysis of the possibility for obtaining marketa ble quartz feldspar concentrates using flotation and electrostatic separation methods. The result s showed that high quality concentrates (possessing the necessary physical and chemical properties) that are suitable for ceramic production can be obtained by flotation of such waste. The use of such waste contributes to reducing waste volumes and ensuring a stable supply of raw materials for the ceramics industry.

Reinforcing effects of nano-WC in AlSi10Mg alloy assisted by in-situ surface modification approach

A series of nano-WC surface modified AlSi10Mg powders with different WC contentswere synthesized by the electrostatic assembly method. After the selective laser melting (SLM) processing, various Al−W intermetallicswere in-situ formed in the SLM nano-WC/AlSi10Mg composites. A well-coherent Al/Al5W interface with a low lattice mismatch of 4.7% was confirmed with an orientation relationship of (002)α(Al)//(104)Al5W. The nano-WC particles and Al−W intermetallics triggeredthe columnar-to-equiaxed transition, leading to a fine equiaxed microstructure. As a result, the SLMed 3 wt.% nano-WC/AlSi10Mg composites showed remarkable mechanical properties, with an ultimate tensile strength of (464.1±8.68) MPa and elongation of (5.6±0.95)%. Additionally, the SLMed 3 wt.% WC/AlSi10Mg samples also achieved the lowest average coefficient of friction (0.429) and wear rate of 3.842×10−5 mm3/(N·m) compared to other WC/AlSi10Mg composites. The remarkable mechanical and wear properties are ascribed to fine-grain and second-phase strengthening.

Study of the Electrostatic Method of Applying Abrasive Grains to the Grinding Tool Backing

Study of the Electrostatic Method of Applying Abrasive Grains to the Grinding Tool Backing

Electrospun carbon nanofibers decorated with NiS2-FeS2 used as efficient counter electrode for quantum dot sensitized solar cells

NiS2-FeS2 composite material is uniformly coated on CNFs by a one-step hydrothermal method with carbon nanofibers (CNFs) prepared by the electrostatic spinning method. A composite NiS2-FeS2/CNFs with Ti-mesh substrate counter electrode (NiS2-FeS2/CNFs CE) is prepared by scraping and coating method on a metal titanium mesh and applied to quantum dot sensitized solar cells (QDSSCs). The photoelectric power conversion efficiency of QDSSCs assembled on NiS2-FeS2/CNFs electrode substrate is 9.85%, which is much higher than that of traditional Cu2S/brass (7.85%). The exceptional achievement can be attributed to the superb amalgamation of the Ti-mesh's excellent electrical conductivity and the NiS2-FeS2/CNFs nanostructure's high and stable catalytic activity. The co-loading of NiS2 and FeS2 reduces the particle size of the composite, enhancing the specific surface area of the counter electrode. It provides abundant catalytic active sites for QDSSCs. The experimental results show that NiS2-FeS2 is expected to be a competitive and efficient QDSSCs CE material.

Quality evaluation of strawberries coated with water-in-oil based emulsion using an advanced electrostatic spray coating system.

In this study, the impact of formulated emulsion was studied on strawberries which were coated using dip and electrostatic spray coatingmethods. The coated strawberries were kept at room temperature for a period of 12days. A significant level of chargeability of w/o emulsion was achieved in terms of charge-to-mass ratio of 2.81 mC/kg at an applied high voltage of 2.0kV, applied air pressure of 0.3MPa, and liquid flow rate of 33.6ml/min. The distance of 170mm from the nozzle tip to Faraday cage was maintained during the measurements. As compared to uncoated and dip coated strawberries, the water-in-oil based electrostatically charged sprays considerably (p < 0.05) reduced theweight loss, decay rate, pH, titrable acidity, TSS, and antioxidant activity. In both the cases, i.e. strawberries coated with dip and electrostatic spraycoating methods, the same weight loss was observed, however, there was a considerably less weight loss as compared to uncoated samples. The textures of the uncoated (9.02 N) and dip coated (12.58 N) samples were significantly different from the electrostatic spray coated (15.85 N) samples. Since, the coating formulation had no impact on the sensory attributes, thesamples were considered as acceptable at the end of the storage. Furthermore, compared to uncoated, water-in-oil based electrostatically charged spray coating was more effective at delaying the decay by 12days.

Fluctuation Relations to Calculate Protein Redox Potentials from Molecular Dynamics Simulations.

The tunable design of protein redox potentials promises to open a range of applications in biotechnology and catalysis. Here, we introduce a method to calculate redox potential changes by combining fluctuation relations with molecular dynamics simulations. It involves the simulation of reduced and oxidized states, followed by the instantaneous conversion between them. Energy differences introduced by the perturbations are obtained using the Kubo-Onsager approach. Using a detailed fluctuation relation coupled with Bayesian inference, these are postprocessed into estimates for the redox potentials in an efficient manner. This new method, denoted MD + CB, is tested on a de novo four-helix bundle heme protein (the m4D2 "maquette") and five designed mutants, including some mutants characterized experimentally in this work. The MD + CB approach is found to perform reliably, giving redox potential shifts with reasonably good correlation (0.85) to the experimental values for the mutants. The MD + CB approach also compares well with redox potential shift predictions using a continuum electrostatic method. The estimation method employed within the MD + CB approach is straightforwardly transferable to standard equilibrium MD simulations and holds promise for redox protein engineering and design applications.

The Localized Surface Plasmon Resonances (LSPR) Origin of W18O49 and Application in Photocatalysis

A key solution for high-efficiency solar-to-fuel conversion is to fabricate semiconductor photocatalysts with ultra-broad spectral absorption and high charge-carriers utilization efficiency [1]. The localized surface plasmon resonances (LSPR) effect of W18O49 induces visible and near-infrared (NIR) light absorption efficiently, realizing full-spectrum solar-light driven photocatalysis [2]. Therefore, it is meaningful to study the LSPR origin and seek ways to make full use of photo-induced hot electron of W18O49. In our work, by density-functional theory calculation, the LSPR has been proposed to originate from the localized electron confinement around lattice W5+–W5+ pairs in the unique structure of W18O49, which explains the experimental results that W18O49 has a broad absorption ranging from visible to NIR region, independent of the particle shape and size. Hierarchical-structured W18O49 microflowers with high absorbance have been coated with ZnIn2S4 nanosheets to achieve cocatalyst-free photocatalytic composite, which exhibits outstanding H2 production of 902.57 µmol within 3 h under simulated solar-light. [3] Z-scheme photocatalytic heterojunction of W18O49 microflowers and g-C3N4 nanosheets has been constructed through electrostatic self-assembly method, which shows higher photocatalytic hydrogen production performance than the counterpart synthesized by hydrothermal method. [4] Reference [1] Q. Wang, K. Domen, Chem. Rev. 2020, 120, 919−985.[2] Z. Y. Zhang, J. D. Huang, Y. R. Fang, et al., Adv. Mater. 2017, 29, 1606688.[3] Y. Lu, X.F. Jia, Z.Y. Ma, et al., Adv. Funct. Mater., 2022, 32, 2203638.[4] Z. Y. Ma, W. P. Li, X. F. Jia, et al., Mater. Today. Adv. 2022, 15, 100249.

Numerical evaluation of respiratory droplet removal by an ionic wind-driven electrostatic device in an indoor environment

A novel method by utilizing self-pumped electrostatic droplet collectors is proposed to remove respiratory droplets in a room. The ionic wind flow pattern and droplet migration and removal process in a room were numerically predicted by the Eulerian-Lagrangian method. The coupling between the corona discharge, air flow and droplet migration processes was realized in the numerical model. Results demonstrate that a circulation flow pattern across the whole room is generated with a velocity magnitude of 1 m s−1. The droplet removal time is mainly governed by the migration of droplets from a specific position to the inlet of the electrostatic droplet collector. The turbulent dispersion of droplets greatly enhances the droplet migration and reduces the droplet removal time by 70 % for droplets with an initial diameter of 20 μm. More than 99 % droplets suspended in the room with a characteristic size of 5 m can be removed in 200 s with a power consumption of about 150 W. Compared with the droplet free deposition, the electrostatic droplet collection method reduces the droplet removal time by more than 90 %.

Molecular Dynamics Study of the Structural and Diffusion Properties of Dehydrated Layered Double Aluminum and Lithium Hydroxide

An atomistic model of dehydrated Cl-doped double layer aluminum–lithium hydroxideLi⋅Al2(OH)6Cl(DALH-Cl), which is a promising material for the sorption of lithium from weak brines, has been developed. The effective charges of the atoms of the system have been determined using the density derived electrostatic and chemical (DDEC6) methods. A molecular dynamics analysis of DALH-Cl has been performed within the developed model. The structural characteristics of three atomic pairs in metallic layers of DALH-Cl and the probability density distribution of atoms in the direction perpendicular to these layers have been calculated. The temperature dependence of the diffusion coefficient of lithium atoms in the space between metallic layers in the temperature range of 325–450 K has been evaluated.

A new electrostatic dust removal method using carbon nanotubes transparent conductive film for sustainable operation of solar photovoltaic panels

Electrostatic dust removal has the advantages of energy saving, high efficiency, and controllability, and has become the preferred dust removal solution for solar photovoltaic (PV) panels in recent years. This paper investigates a new electrostatic adsorption dust removal method for solar PV panels based on the electrostatic dust removal effect of carbon nanotubes (CNTs) transparent conductive films. In the sheet resistance range of 500–1×105 Ω/□, the electrostatic dust removal effect of CNTs transparent conductive films has little relationship with the film sheet resistance, and when the electric field strength in the dust removal area is 6 kV/cm, the final dust removal rate of different films can reach more than 98.6 %, and the power generation efficiency of the PV panels can reach 94–97 % of that of the ordinary PV panels in the surface clean state after dust removal. The influence of the environment on the dust removal effect is mainly reflected in the relative humidity. When the relative humidity of the dust removal environment is 70 %, it shows the optimal dust removal effect, and the electric field strength required for the dust particles to jump is the lowest, which is 2.46 kV/cm. The highest dust removal efficiency can be achieved by using a metal plate with a lower surface curvature of 1/9.08 cm−1, and the final dust removal rate can reach 98.92 %. The research results are of great significance for further developing electrostatic dust removal technology in the solar PV panel dust removal field.

Particle simulations of ion-extraction process from a decaying plasma assisted by radio-frequency plasma heating

In this study, two-dimensional kinetic particle simulations were employed to examine the potential of radio-frequency (rf) plasma heating in enhancing ion extraction efficiency in a decaying plasma with the configuration of parallel plates. The numerical results suggest that the application of rf power based on the direct current electrostatic method leads to a remarkable increase in the ion extraction flux, thereby reducing the time required for ion extraction. The increase in the ion extraction flux is attributed to the enhancement of the penetration ability of the rf electric field into the plasma, especially in cases of high rf frequencies, which can elevate the bulk electron temperature to approach 10 eV. The propagation speed of ion rarefaction waves is enhanced by the increased electron temperature, speeding up the process of ion extraction. The study also found that an increase in rf voltage causes more intense plasma oscillations to screen out the rf disturbance, further increasing the electron temperature. Furthermore, as ion extraction continues, the heating effect of rf frequencies was found to be enhanced due to the decay of plasma density.