Preparation Of Zinc Research Articles

Preparation of Zinc–Lanthanum and Zinc–Aluminum–Lanthanum Layered Double Hydroxides and Analysis of Their Thermal Stabilization Mechanism on PVC

Preparation of Zinc–Lanthanum and Zinc–Aluminum–Lanthanum Layered Double Hydroxides and Analysis of Their Thermal Stabilization Mechanism on PVC

Preparation and properties of unsaturated zinc carboxylate/EPDM composites

ABSTRACT The unsaturated zinc carboxylate/Ethylene-Propylene-Diene Monomer (EPDM) composites were prepared by mechanical blending. The effects of hydroxy (2-methylprop-2-enoato-O)zinc (ZMMA) and zinc dimethacrylate (ZDMA) on the hydrophobicity, mechanical properties, ageing resistance, and electrical properties of the composites were studied. The results show that the mechanical properties, crosslinking rate, crosslinking density, and oil resistance of the composite are significantly improved with the increase of ZMMA and ZDMA content. The crosslinking density of EPDM filled with 15 phr of ZDMA composite material is 3.22 × 10−3 mol/cm3, compared with the samples without ZDMA filling, the improvement was 175.2%, and the tensile strength reaches 16.9 MPa, which increases by 33.6%. The addition of a small amount of unsaturated carboxylate has a positive effect on the electrical properties of EPDM matrix composites. The volume resistivity of the EPDM filled with 5 phr of ZDMA is 16.2 × 1013 Ω·m, an increase of 36.1%.

Preparation and Capacitive Properties of Ni-Doped Zinc Cobaltate/Carbon Fiber Composite Porous Mesh Materials

Nickel-element-doped zinc cobaltate/carbon fiber composites (Ni-ZnCo2O4/CF) were prepared on carbon cloth (made of a combination of carbon fibers) conductive substrates using a simple ambient stirring method combined with heat treatment. Characterization tests of the materials revealed that the prepared products were porous Ni-ZnCo2O4/CF mesh structures. This porous network structure increases the surface area of the material and helps shorten the diffusion path of ions and electrons. The samples were analyzed using X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) methods to investigate the effect of Ni elemental doping on the stability of the materials. The results show that there are no other impurity peaks and no other impurity elements in the Ni-ZnCo2O4/CF electrode material, which indicates that the sample purity is high. Meanwhile, the electrochemical properties of Ni-ZnCo2O4/CF electrode materials were studied. Under the condition of 15 A·g−1, the specific capacitance of Ni-ZnCo2O4/CF electrode material is 1470 F·g−1, and after 100 cycles, its specific capacity reaches 1456 F·g−1, which is 99.0% of the specific capacity of 1470 F·g−1, indicating that the electrode material has good stability. In addition, we assembled asymmetric supercapacitors (Ni-ZnCo2O4/CF//CNTs) with Ni-ZnCo2O4/CF as the positive material and carbon nanotubes (CNTs) as the negative material. In the cyclic stability experiment of Ni-ZnCo2O4/CF/CNTs devices, when the current density was 1 A·g−1, the specific capacitance was 182 F·g−1. After 10,000 cyclic charge–discharge tests, the specific capacity became 167 F·g−1, which was basically unchanged compared with the initial specific capacity, reaching 91.8%. It shows that it has higher charge–discharge performance and higher cycle stability.

Preparation and Synergistic Antibacterial Effect of Zinc and Cerium Co-Doped Silica

Preparation and Synergistic Antibacterial Effect of Zinc and Cerium Co-Doped Silica

Preparation and lithium storage properties of zinc ferrite/sulfur-nitrogen co-doped carbon nanotubes composites

ZnFe2O4 nanoparticles/S, N co-doped carbon nanotube composites were prepared by a microwave-assisted method with low cost, low energy consumption and easy commercialization. Through the strategies of nanosizing, heteroatom doping, and compounding with advanced carbon materials, the inherent disadvantages of poor electronic conductivity and low ion diffusion rate of transition metal oxides are improved, and the volume expansion of ZnFe2O4 during cycling is slowed down by using carbon nanotubes with high specific surface and high mechanical strength as the material support skeleton, which enhances the cycling stability of the material. At a current density of 0.1 A g−1, the specific capacity of 716.23 mAh g−1 was maintained after 100 charge/discharge cycles. The charge/discharge cycle at a high current of 2 A g−1 still has a specific capacity of 309.90 mAh g−1.

Synthesis, Structural Characterization, and Phosphorescence Properties of Trigonal Zn(II) Carbene Complexes.

The sterically demanding N-heterocyclic carbene ITr (N,N'-bis(triphenylmethyl)imidazolylidene) was employed for the preparation of novel trigonal zinc(II) complexes of the type [ZnX2(ITr)] [X = Cl (1), Br (2), and I (3)], for which the low coordination mode was confirmed in both solution and solid state. Because of the atypical coordination geometry, the reactivity of 1-3 was studied in detail using partial or exhaustive halide exchange and halide abstraction reactions to access [ZnLCl(ITr)] [L = carbazolate (4), 3,6-di-tert-butyl-carbazolate (5), phenoxazine (6), and phenothiazine (7)], [Zn(bdt)(ITr)] (bdt = benzene-1,2-dithiolate) (8), and cationic [Zn(μ2-X)(ITr)]2[B(C6F5)4]2 [X = Cl (9), Br (10), and I (11)], all of which were isolated and structurally characterized. Importantly, for all complexes 4-11, the trigonal coordination environment of the ZnII ion is maintained, demonstrating a highly stabilizing effect due to the steric demand of the ITr ligand, which protects the metal center from further ligand association. In addition, complexes 1-3 and 8-11 show long-lived luminescence from triplet excited states in the solid state at room temperature, according to our photophysical studies. Our quantum chemical density functional theory/multireference configuration interaction (DFT/MRCI) calculations reveal that the phosphorescence of 8 originates from a locally excited triplet state on the bdt ligand. They further suggest that the phenyl substituents of ITr are photochemically not innocent but can coordinate to the electron-deficient metal center of this trigonal complex in the excited state.

Preparation and Structure of Zinc–Calcium Hydroxyapatite Solid Solution Particles and Their Ultraviolet Absorptive Ability

The calcium ions (Ca2+) of calcium hydroxyapatite (CaHap) were substituted with zinc ions (Zn2+), and zinc–calcium hydroxyapatite solid solution (ZnCaHap) particles were prepared via a precipitation method. The structure of the various obtained particles was investigated via powder X-ray diffraction, field emission scanning electron microscopy and energy dispersive X-ray spectrometry. The ultraviolet (UV) absorption ability of the particles was also investigated using UV–Vis spectroscopy. The morphology of the CaHap comprised fine ellipsoidal particles, and long rod-like particles and large plate-like particles were mixed with the fine particles at higher Zn2+ contents in the particles. Pure ZnCaHap particles were obtained from the starting solution at less than Zn/(Zn + Ca) ([XZn]) of 0.25. Another crystal phase was mixed with the ZnCaHap phase at [XZn] ≥ 0.25. The crystallinity and lattice parameters a and c of the particles decreased with an increase in [XZn] from 0 to 0.10. The UV absorptive ability of the particles first increased and then decreased with increasing Zn2+ content and showed a maximum at [XZn] = 0.30.

Preparation and Characterization of Zinc(II)-Based Lewis/Brønsted Acidic Deep Eutectic Solvents.

Lewis/Brønsted acidic deep eutectic solvents (LBDESs) are a recent class of solvents that combine the two types of acidity. In some cases, this synergy leads to enhanced catalytic properties for many reactions and applications. For this reason, it is important to discover more LBDESs. In this work, we prepared and characterized four different zinc(II)-based LBDESs, mixing ZnCl2 and various Brønsted acids: acetic, glycolic, levulinic, and formic acids. Apart from the latter, for which the corresponding DES is not thermally stable, the samples have been characterized in terms of density, viscosity, and conductivity. Notably, as zinc(II) is a diamagnetic metal, all of them are suitable for NMR spectroscopy, for example, for kinetic and mechanistic studies.

Synthesis of Metal Nanoparticles via Pulicaria undulata and an Evaluation of Their Antimicrobial, Antioxidant, and Cytotoxic Activities

Nanoparticle engineering via plants (green synthesis) is a promising eco-friendly technique. In this work, a green protocol was applied to the preparation of silver, zinc, and selenium nanoparticle solutions supported by the extracted aerial parts of Pulicaria undulata. The formation of nanoparticles in the solution was characterized using phytochemical analysis, and UV-visible, TEM, and zeta-potential spectroscopy. In addition, various biological activities were investigated for the extract of P. undulata and the produced nanoparticles (selenium, silver, and zinc), including antioxidant, antimicrobial, and cytotoxic activities. The volatile components of the extracted constitute verified the fact that twenty-five volatile components were characterized for the majority of abundant categories for the fatty acids, esters of fatty acids (59.47%), and hydrocarbons (38.19%) of the total area. The antioxidant activity of P. undulata extract and metal nanoparticles was assessed using DPPH assay. The results indicated reduced potency for the metal nanoparticles’ solutions relative to the results for the plant extract. The cytotoxicity of the investigated samples was assessed using an MTT assay against various tumor and normal cell lines with improved cytotoxic potency of the solutions of metal nanoparticles, compared to the plant extract. The antimicrobial activity was also estimated against various bacterial and fungal species. The results confirmed amended potency for inhibiting the growth of microbial species for the solutions of metal nanoparticles when compared to the extracted aerial parts of the plant. The present study showed that green synthetized nanoparticles using P. undulata have various potential bioactivities.

Preparation and Characterization of Slow-Release Zinc and Iron Fertilizer Encapsulated by Palm Stearin

Using granular form application in the pisciponic system, this study investigates the effects of supplementation in the pisciponic system on plant growth performance. This study was conducted at the Aquaculture Experimental Station in Puchong, Selangor. The experiment was set up in a greenhouse with a plastic liner at the bottom. The coated fertilizers were immersed in 500 mL of distilled water in the beakers. The immersion times were analyzed for each 3, 6, 12, 18, 24, 30, 36, 42, 48, 54, 60, 66, and 72 hours. Insoluble solids and water were then filtered using filter paper and dried in the oven, followed by the drying process to obtain a constant weight before being put in the desiccators. During the release test, the distilled water was taken at every 48-hour interval, and the concentration of nutrients was determined from the atomic absorption spectrometer. The findings indicate that the weights of release fertilizers, specifically Zn and Fe, significantly decreased over time. At the lowest concentration, the coated zinc and iron weights decreased as time increased. Referring to the curve results, the Zn fertilizer started drastically decreasing its weight at hour 24, which decreased approximately to 0.002 for every subsequent hour. Meanwhile, Fe fertilizer decreased drastically at hour 66, where the weight dropped from 0.10467 to 0.039. However, the final weights for both fertilizers at hour 72 were about the same.

Preparation of zinc oxide/halloysite compound and their reinforcement for styrene butadiene rubber composite

This study investigated the surface treatment of halloysite nanotubes (HNTs) with zinc oxide (ZnO) and used to enhance the mechanical properties of butyl rubber (SBR) composites. The prepared ZnO-modified HNTs (ZnO/HNTs) was characterized by X-ray diffraction (XRD), Fourier infrared spectroscopy (FT-IR), Scanning electron microscopy (SEM) and Transmission electron microscopy (TEM). The results indicated that ZnO particles were successfully loaded on the surface of HNTs and interacted with hydroxyl groups. The outer surface of HNTs became rough due to the loading of ZnO. The effects of ZnO/HNTs on the processing and mechanical properties of filled SBR composites were evaluated. The results showed that the ZnO/HNTs particles displayed a fine dispersion in the matrix system and have a strong interaction compatibility with rubber matrix chains. The tensile strength reached at the maximum of 9.35 MPa at a filler content of 60 phr, which was 405% and 31.69% higher than those of pure SBR and the HNTs/SBR composites, respectively. The enhancement of the mechanical properties of filled SBR composites is attributed to the fine dispersion of the ZnO/HNTs particles in the SBR matrix and the improved incorporation between the rubber molecules and the filler particles due to the loading of ZnO on the surface of HNTs, which restricts the movement of the rubber chains by entrapping molecules when the composites is subjected to stress loading.

Preparation of sodium zinc phosphate/polyaniline nanocomposite for Cr(VI) and eriochrome black T adsorption from water

In this study, ultrasound physical mixing of polyaniline (PAni) and sodium zinc phosphate (NaZnP) materials resulted in the synthesis of a new nanocomposite (NaZnP/PAni). Samples were physicochemically characterized via different analytical techniques. The X-ray diffraction pattern indicated the synthesis of hydrated sodium zinc phosphate (Na6(ZnPO4)6.8 H2O) with an average crystallite size of 40.8 nm. After physical mixing with PAni, the crystallite size of the resulting composite was reduced to 36 nm. Scanning electron microscopy (SEM) revealed that the nanocomposite was formed by the deposition of NaZnP nanospheres over PAni nanorods. The adsorption efficiency of the composite was monitored using an azo dye (eriochrome black T (EB)) and hexavalent chromium (Cr(VI)). The optimization of the effects of operating parameters (pH, NaZnP/PAni dosage, starting pollutants concentration, and reaction time) on the removal efficiency were examined using the central composite design (CCD). The predicted removal efficiencies under the optimum conditions were 93 % and 98 % for EB and Cr(VI), respectively. The adsorption kinetics modeling reveals that the pseudo-second-order describes the uptake of Cr(VI) and EB. Equilibrium data fitted well with the Redlich-Peterson and Sips isotherm models. The highest retention capacity of NaZnP/PAni was 234 mg/g for EB and 231 mg/g for Cr(VI). Consequently, the developed NaZnP/PAni nanocomposite could be applied to remove heavy metals and dyes from wastewater with great efficiency.

Protein interactions and drug displacement studies of novel copper(II) and zinc(II) complexes of a dipyrazinylpyridine ligand

A one-pot method was employed for the preparation of zinc and copper complexes of 4-methoxyphenyl-2,6-di(pyrazine-2-yl)pyridine ligand (L). The complexes were designed to acknowledge their potential as selective binders with serum albumins. The reaction of the metal chlorides with an excess of ligand L yielded mononuclear [CuL2]Cl2 (1) and [ZnL2]Cl2 (2) complexes. 1H NMR, UV–Vis spectroscopy, ESR, HRMS, XRD, and elemental analysis were carried out to characterize the complexes. The interactions of the synthesized complexes with Human Serum Albumin (HSA) and their drug displacement properties using ibuprofen and warfarin were investigated with the help of spectroscopic as well as molecular modeling techniques. Complex 1 exhibited better binding capability, indicated by its binding constant value (31.2 × 104 M−1) towards HSA, than complex 2 (5.6 × 104 M−1), as depicted from UV–Visible and fluorescence spectroscopic studies. Moreover, the complexes showed better binding affinity towards HSA than the corresponding free ligand (0.2 × 104 M−1). The mechanism through which fluorescence quenching of HSA takes place (when metal complexes 1–2 were added to it) is static in nature. The Stern-Volmer (SV) equation was utilized to deduce the binding constants (Kb) through a fluorescence titration method. Moreover, structure optimization of the synthesized complexes and theoretical studies using density functional theory (DFT) has been carried out to determine the nature of the interaction of the complexes with the biomolecules.

Plant extracts-mediated green synthesis of zinc oxide/carbon nanofiber nanocomposites with highly efficient photocatalytic and antimicrobial properties for wastewater treatment

In the present study, a novel biosynthesis method for the preparation of zinc oxide/carbon nanofiber nanocomposite (ZnO-CNFs) is proposed along with evaluated their photocatalytic and antimicrobial properties for wastewater treatment. For biosynthesis of ZnO-CNFs, plant extracts of Thymus daenensis (TD) and Stachys pilifera Benth (SB) were used as both green-reducing agents and aqueous carbon-rich sources. The photocatalytic activity of the synthesized ZnO-CNFs was studied in the photodegradation of tetracycline antibiotic residues in contaminated water. The photocatalytic test (UVA irradiation, λ = 365 nm) results showed that the photodegradation efficiency of tetracycline by ZnO-CNFTD was 93.65 ± 2.1 %, 73.58 ± 1.5 %, 67.41 ± 1.7 %, and 81.28 ± 2.1 % in ultrapure water, infectious disease hospital 1, infectious disease hospital 2, and general hospital influents, respectively. Furthermore, the antimicrobial activity was examined against Escherichia coli (E. coli) and Bacillus subtilis (B. subtilis) bacteria and Candida albicans (C. albicans) fungus. To this end, the antibacterial behaviors of ZnO-CNFs were studied based on minimal inhibitory concentration (MIC) ranges and diameter of inhibition zone, which indicated that the ZnO-CNFs exhibited superior antibacterial activity against Gram-positive (B. subtilis) and Gram-negative (E. coli) bacteria compared to ZnO nanoparticles. Also, the antifungal activity of ZnO-CNFTD with MIC range of 156.25–625 μg mL−1 was more potent than ZnO nanoparticles with MIC range of 156.25–2500 μg mL−1. Overall, our findings indicate that the synthesized ZnO-CNFTD exhibits excellent photocatalytic and antimicrobial potential compared to ZnO nanoparticles and therefore can be a promising candidate for effective treatment of water contaminated with microorganisms and organic compounds.

Preparation and characterization of zinc modified calcium silicate/polycaprolactone with graphene oxide composite coating for bone repair applications

The goal of biomaterial interest is the ease of the bone tissue regeneration process or the replacement of damaged bone and other tissues with recently generated bone tissue. Calcium silicate (CaSi) bioceramic is a vital material for bone tissue engineering, predominantly for bone repair. Though, the low toughness of calcium silicate imitates its load-bearing applications. The electrophoretic deposition technique was used to coat various concentrations of Zn2+ substituted CaSi on TNT. In this work, a novel as-obtained an appropriate orthopedic implant hybrid material by charged calcium ions of mineralized calcium silicate united with PCL-negatively charged graphene oxide [Zn-CaSi (S1-S3)/PCL (P1-P3)/GO]. Hence, the effectively as-obtained [Zn-CaSi (S1-S3)/PCL (P1-P3)/GO] bone-like apatite on the ternary composite coatings on the surface was proven via XRD, FT-IR, FESEM with EDAX spectra, HR-TEM and BET analyses etc., Moreover, the TNT/S2/P2@GO ternary composite coatings exhibit better mechanical properties and antibacterial activity. The metal ions released from the coatings were calculated via ICP-AES studies. Moreover, the cell viability and also the live/dead staining of MG63 human osteoblasts cells on the subsequent composite coating material for better cell growth in orthopedic applications.

Preparation and characterization of zinc–borate glasses doped with Ag2O

Using the melt quenching approach, glasses having the formula ZnO-B2O3-Ag2O have been created.Utilising the X-ray diffraction technique, the synthesized glass has been described. The Archimedes method was used to compute the densities of these glasses,and the appropriate formula was used to determine the associated molar volume.Absorption spectra were recorded using a UV–visible spectrometer.Tauc's figure has been used to examine the energy band gap.Ag2O concentration-related variations in band gap energy have been discussed.

Preparation of 6N5 (99.99995%-Pure) Cadmium, Zinc, and Tellurium by Crystallization Methods

Preparation of 6N5 (99.99995%-Pure) Cadmium, Zinc, and Tellurium by Crystallization Methods

Electrochemical reduction mechanism of Zn2+ in molten NaCl−KCl eutectic

A process comprising selective chlorination and molten salt electrolysis was proposed to develop an efficient and environmental-friendly technology for zinc recovery from metallurgical dusts. The theoretical feasibility of this technology was firstly estimated based on thermodynamic fundamentals. Subsequently, the electrochemical behavior of Zn2+ on tungsten electrode was investigated in molten NaCl−KCl eutectic at 973 K by many electrochemical transient methods. The results showed that the reduction of Zn2+ on tungsten electrode was found to be a one-step process exchanging two electrons with the initial reduction potential of −0.74 V (vs Ag/AgCl), and the electrode process was considered as quasi-reversible and controlled by diffusion. The diffusion coefficient of Zn2+ ions in the melts was determined in the order of 10−5 cm2/s. Finally, the electrolytic preparation of zinc was carried out by potentiostatic electrolysis in molten NaCl−KCl−ZnCl2 eutectic at −1.6 V (vs Ag/AgCl). Spheroidic granular metal with silver-white luster was attained after electrolysis for 9.5 h, and identified as pure Zn. The present study confirms that it is practically feasible to extract pure zinc metal by direct electrolysis of ZnCl2 in molten NaCl−KCl eutectic, and provides a valuable theoretical reference for the efficient recovery of zinc from metallurgical dusts.

Preparation of Zinc Oxide/Graphite Composite Using Solid-State Method as an Anode Material for Lithium-Ion Battery

Lithium-ion batteries using zinc oxide (ZnO) as anode material had a high theoretical capacity of about 987 mAh/g. Unfortunately, ZnO capacity can drop below 200 mAh/g after only a few cycles. For that reason, graphite was added in this study due to its stable theoretical capacity of around 348-374 mAh/g to maintain the stability of lithium-ion battery capacity. Zinc oxide/graphite (ZnO/Graphite) was prepared using a solid-state method, in which ZnO and graphite were mortared until homogeneous with the mass ratio of (2:1), (1:1), and (1:2). The SEM images of all samples showed the agglomerate morphology between ZnO and graphite which affect the results of the battery performance test. The final result of the ZnO/Graphite anode can be considered a continuous anode material due to the stable cycle performance obtained in the range of 219.72–371.27 mAh/g with a decreased value of 40% after 55 cycles.

Preparation and characterization of zinc–aluminum layered doubled hydroxide/ graphene nanosheets composite for supercapacitor electrode

Graphene nanosheets were synthesized using the liquid phase exfoliation technique while zinc-aluminum layered doubled hydroxides (ZnAl-LDHs) were fabricated using the chemical bath deposition method. A composite of graphene/Zn–Al LDHs was synthesized and used as an electrode for the supercapacitor . ZnAl-LDHs present a well-standing nanosheets-like structure that covered the entire area of the substrate. The thickness of these nanosheets was found to be between 60 and 80 nm. The SEM images of the graphene/Zn–Al LDHs composite display graphene nanosheets next to the LDHs nanosheets. The optical band gap of this composite was found to be about 4 eV. The obtained electrode exhibited excellent supercapacitive performances with the highest specific capacitance of ∼ 140 F / g along with the maximum energy, and power densities of 15.359 k W K g − 1 and 2.016 W h K g − 1 , respectively. The as-prepared composite showed long-term stability and it retains 97% of the initial capacitance after 2000 charge-discharge cycles. The electrochemical impedance spectroscopy (EIS) results confirm the contribution of both ZnAl-LDHs and graphene in the supercapacitor system. The fabricated electrode using the present simple strategy in this report can be further extended to manufacture other electrodes using other composites from the same family for the upcoming energy storage systems. • Composites of ZnAl-LDHs/graphene was synthesized. • ZnAl-LDHs presents vertically aligned 2D sheets. • Graphene sheets are placed near the obtained ZnAl-LDHs. • The obtained electrode exhibited an excellent supercapacitive performances. • The obtained electrodes presented C P ∼ 140 F / g and PD of ∼ 15.359 k W K g − 1 and ED. ∼ 2.016 W h K g − 1