Preparation of Very Thin Zinc Oxide Films by Liquid Deposition Process: Review of Key Processing Parameters

We used sol-gel and spin-coating in the original configuration of a liquid deposition process to synthesize particularly thin ZnO films (<100 nm) with nano-granular morphology, high grain orientation and variable optical properties. The concentration of the zinc salt, the concentration of the chelating agent, the nature of the solvent and the substrate material have been identified as key parameters that determine the microstructure of the deposited layer and thus its final properties. The thorough and practical examination of the effects of the synthesis parameters evidenced a three-step growth mechanism for these ZnO thin films: (i) a reaction of precursors, (ii) a formation of nuclei, and (iii) a coalescence of nanoparticles under thermal annealing. The growth of these very thin films is thus conditioned by the interaction between the liquid phase and the substrate especially during the initial steps of the spin coating process. Such thin ZnO films with such nano-granular morphology may be of great interest in various applications, especially those requiring a large active surface area.

Field Bio-efficacy and Residue Dynamics of the Fungicide Polyoxin D Zinc Salt 5% SC in Grape (Vitis vinifera)

The field experiments were carried out to evaluate the bio-efficacy and residue dynamics of Polyoxin D Zinc salt 5% SC in grape during 2014–2015 and 2015–2016 at ICAR-National Research Centre for Grapes, Pune. Polyoxin D Zinc salt 5% SC @ 600 ml ha-1 gave the best control of the disease, both in the leaves and bunches with a percent disease control of 56.4 and 75.7 respectively, as compared to untreated control. The percent disease control of the test fungicide Polyoxin D Zinc salt 5% SC @ 600 ml ha-1 was superior to all the triazoles viz. Flusilazole 40 EC, Hexaconazole 5 EC and Myclobutanil 10 WP, used in the study. The yield data reflected a similar trend wherein the maximum percent increase in yield was observed in case of Polyoxin D Zinc salt 5% SC @ 600 ml ha-1 i.e. 57.47 as compared to untreated control. However, all the triazoles manifested a higher percent increase in yield as compared to the lowest dose of the test fungicide i.e. 200 ml ha-1. For the detection and quantification of polyoxin D residue in grape, we have developed an efficient and effective analytical method, using liquid chromatography-tandem mass spectrometry (LC-MS/MS), in field treated samples. The residue data had excellent fit to 1st+1st order models giving r2 value of >0.99 with a half-life (t1/2) 8.0 days for recommended dose and 14.5 days for double dose. These findings are useful for effective disease management in grape crop amalgamated with food safety and consumer satisfaction.

ZnO and Simonkolleite Nanocomposite Synthesis via Green Chemistry Using Hibiscus Flower Extract

In the present work, zinc oxide (ZnO) and Simonkolleite (SK) nanocomposite was prepared using a facile green synthesis route, using hibiscus flower extract. Zinc chloride as starting solution was mixed with hibiscus plant extract. The zinc salt molarity was varied in order to investigate its effect on the synthetized nanocomposite structure. The synthetized nanocomposite were characterized by mean of X rays diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) and X-ray photoemission spectroscopy (XPS). The results indicated that the zinc chloride molarity plays a key role in zinc oxide and simonkolleite nanopowder synthesis. The increase in zinc salt molarity above 0.1M yields to a pure simonkolleite. While, at low zinc salt molarity, the formed nanoparticles are composed of mixture of simonkolleite and ZnO. The thermal treatment causes a partial conversion of simonkolleite to ZnO.

Synthesis of ZIF-11- effect of source of zinc salts on the structure

In this paper, ZIF-11 material was synthesized from benzimidazole and different zinc salt sources at room temperature. The obtained samples were characterized using XRD, SEM, FTIR and TGA measurements. The results showed that the synthesized materials had nano-size, and uniformity with the sharp dodecahedrons structure of ZIF-11. Zinc sources had an influence on the size and nature of the ZIF-11 crystal. The average crystalline size of the nanoparticles calculated by Scherrer equation were 85.5 nm for sample of zinc nitrate, 91.9 nm for sample of zinc chloride and 111.5 nm for sample of zinc acetate. The obtained samples had high thermal stability ( 460 °C). The adsorption capacity of the synthesized materials for iodine from aqueous solution was very high (236 mg/g).

Coating Metals with Zinc and Method for Measuring the Thickness of the Layer

When a copper coin is immersed with zinc into a solution of a zinc salt (ZnSO4, ZnCl2 etc.) an electrochemical eaction occurs in the mixture. As a result, a thin layer of zinc appears on the surface of the copper which gives the impression for silver color. The purposes of this project are: to explain the phenomenon and to investigate relevant parameters; to measure the thickness of the zinc layer; to determine which metals can be covered with zinc in such experiments. Method for measuring the thickness of the zinc layer was obtained by using dimension properties of the coin – radius, height and mass. The advantage of this method is the fact that it can be applied for all metals whose form has an integrable volume. The thickness of the layer was determined to be in the order of 1 . The relationship between the thickness of the zinc and the time at which the coin has spent in the solution was also studied and an exponential tendency was observed. It was proved that only metals after hydrogen in the Reactivity series can be plated with zinc with this setup.

Three-Dimensional Walnut-Like, Hierarchically Zn-MOF Microsphere: One-Pot Synthesis, Characterization And Its Application as a Green Catalyst For The Asymmetric Hantzsch Synthesis of Polyhydroquinolines

A three-dimensional walnut-like, microsphere Zn-based MOFs system was designed and synthesized via hydrothermal reaction of zinc salt with 4,6-diamino-2-pyrimidinethiol as a tridentate ligand. Besides, Zn ions were coordinated to the ligand’s functional groups to give a novel Zn-MOF microsphere material. Afterward, the resultant material was thoroughly characterized by various analysis and physico-chemical methods; including, FT-IR, XRD, TGA, EDX, X-ray mapping, SEM, TEM, and BET analysis. The Zn-MOF microspheres were utilized in the Hantzsch reaction for selective synthesis of asymmetric polyhydroquinolines, using various aromatic aldehydes. Our strategy provides a way for controlled synthesis of the hierarchically nanoporous Zn-MOF microspheres with well-defined morphology, structure, and excellent catalytic properties, resulting in having a promising heterogeneous catalyst for a selective synthesis with good yields in the short reaction time and a low limit of steric hindrance and electronic effects. Besides, the heterogeneity of the catalyst is further tested with hot filtration and also the reusability results point.

Zinc Influx Restricts Enterovirus D68 Replication

Enterovirus D68 (EV-D68) is a respiratory viral pathogen that causes severe respiratory diseases and neurologic manifestations. Since the 2014 outbreak, EV-D68 has been reported to cause severe complications worldwide. However, there are currently no approved antiviral agents or vaccines for EV-D68. In this study, we found that zinc ions exerted substantial antiviral activity against EV-D68 infection in vitro. Zinc salt treatment potently suppressed EV-D68 RNA replication, protein synthesis, and infectious virion production and inhibited cytopathic effects without producing significant cytotoxicity at virucidal concentrations (EC50=0.033mM). Zinc chloride (ZnCl2) treatment moderately inhibited EV-D68 attachment. Time-dose analysis of EV-D68 structural protein VP1 synthesis showed stronger suppression of VP1 in the culture medium than that in the cell lysates. Furthermore, a zinc ionophore, pyrrolidine dithiocarbamate, which can transport zinc ions into cells, also enhanced the anti-EV-D68 activity of ZnCl2 treatment. Taken together, our results demonstrated that the enhancement of zinc influx could serve as a powerful strategy for the therapeutic treatment of EV-D68 infections.

Catalytic Enantioselective Addition of Alkylzirconium Reagents to Aliphatic Aldehydes

A catalytic methodology for the enantioselective addition of alkylzirconium reagents to aliphatic aldehydes is reported here. The versatile and readily accessible chiral Ph-BINMOL ligand, in the presence of Ti(OiPr)4 and a zinc salt, facilitates the reaction, which proceeds under mild conditions and is compatible with functionalized nucleophiles. The alkylzirconium reagents are conveniently generated in situ by hydrozirconation of alkenes with the Schwartz reagent. This work is a continuation of our previous work on aromatic aldehydes.