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Crystalline phase evolution in nanostructured copper sulfide thin films prepared by spray pyrolysis method: the effect of annealing

Nazari R. R., Taloobaghi H. E., Eshghi H.

Materials Science Poland

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2017

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Vol. 35, No. 3

673--680

EN

In this study, physical properties of copper sulfide thin films deposited on glass substrates by spray pyrolysis method at different temperatures (260 °C, 285 °C and 310 °C) were investigated. The influence of annealing time on the physical properties of grown layers was also studied. According to FESEM images, the sizes of the compact copper sulfide grains were varied from about 100 nm to 60 nm. Hall effect and resistivity measurements confirmed that all samples had p-type conductivity. The XRD patterns showed that, together with the dominant digenite phase (Cu1.8S) in all samples, the copper-rich phases also appeared as a result of increasing substrate temperature. The optical UV-Vis spectra analysis showed that due to increasing the substrate temperature, the band gap of the layers was reduced from about 2.4 eV to 2.0 eV. We found that as a result of annealing at 400 °C for 1.5 h in Ar atmosphere, the sample which was initially grown at 310 °C with the highest copper content, totally transformed into the polycrystalline monoclinic chalcocite phase (Cu2S) with 3D nanoporous architecture.

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Efficient Synthesis of Macrocyclic Dilactam Crown Ethers by Fast Addition Method

Rahimzadeh M., Eshghi H., Rostami F., Faghihi Z.

Polish Journal of Chemistry

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2005

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Vol. 79 / nr 1

73-81

EN

A simple and convenient method for preparing macrocyclic dilactam crown ethers containing N2O5, N3O3, N3O4, N3O5 and N2O10 donor atoms with 18-32 membered rings was developed. These compounds were obtained in the macrocyclization step under vigorous stirring conditions as well as fast addition of reactants. This step does not require external cyclization factors such as high dilution approach, template effect or nitrogen protection and provides the expected dilactams in high yields, ranging from 65-95%. The course of the reaction is assumed to depend on the occurrence of self assembly phenomena which are stimulated by a logic concentration in a selected solvent and the yields are improved by application of high speed stirring and fast addition of reactants.

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Differential Pulse Polographic Study of mercury Complexes with Some Benzo-Substituted macrocyclic Diamides in Binary Nitromethane+Dimethylformamide Mixtures

Shamsipur M., Fakbari A. R., Sharghi H., Eshghi H., Ganjali M. R.

Polish Journal of Chemistry

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2002

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Vol. 76 / nr 12

1665-1671

EN

The complex formation of Hg2+ ion with five recently synthesized benzo-substituted macrocyclic diamides in binary nitromethane + dimethylformamide mixtures was studied by differential pulse polarography at 25_C. The stoichiometry and stability of the complexes were determined by monitoring the shift in the Hg2+ differential pulse peak potential against the macrocycles concentration. In all cases studied, it was found that the stability of the resulting 1:1 complex decreases drastically by increasing the amount of dimethylformamide in the binary mixtures. The observed stability order in a given solvent mixture is discussed in terms of the cavity size, structural flexibility and nature of the substituted on the macrocyclic diamide ring.