Density Functional Theory on the Polymerization of Diaminofluorene
Fuad A. Asswadi,
Ali H. Aldhamri,
Fathy A. Abeed
Issue:
Volume 3, Issue 2, April 2015
Pages:
18-22
Received:
21 January 2015
Accepted:
6 February 2015
Published:
2 March 2015
Abstract: Density- functional theory (DFT) calculations on 2,7-diaminofluorene in order to understand the various possible mechanisms of growth, there are two possible mechanisms on it which involve the coupling of cationic radicals with another cationic radical or with a neutral oligomer. The electrochemical properties of this oligomer is understood, but until now there is very little known about the nature of the intermediates and the transition states leading to polymerization. The initial oxidation, forming stable intermediates, releasing protons and further oxidations are studied in terms of the charges distributions, energies changes in the geometry and vibrational frequencies have been calculated using DFT (B3LYP). Dramatic differences have been observed in the infrared band intensities of the cations compared to their neutral parents. Hydrogen bonding between DAF molecules in the crystal structure the direct comparison of theoretical calculations with experiment, so Hartree-Fock (HF) and Becke-Perdew density-functional theory (DFT) calculations are used as benchmarks for the semiempirical and molecular mechanics results.
Abstract: Density- functional theory (DFT) calculations on 2,7-diaminofluorene in order to understand the various possible mechanisms of growth, there are two possible mechanisms on it which involve the coupling of cationic radicals with another cationic radical or with a neutral oligomer. The electrochemical properties of this oligomer is understood, but un...
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Nanosized NiFe2O4/ Active Carbon Composite as Efficient Adsorbent for Azo Dyes and Colours
Ghobad Ranjeh,
Mahdi Radmanesh,
Anooshirvan Kiafar
Issue:
Volume 3, Issue 2, April 2015
Pages:
28-34
Received:
27 January 2015
Accepted:
2 February 2015
Published:
9 April 2015
Abstract: Much attention has been paid on nanomaterials in recent years due to their fundamental and technological applications. The physical and chemical properties of nanomaterials have been enhanced because of their surface-to-volume ratio. Spinel ferrite with the general formula of MFe2O4 (M is a divalent cation) have attracted much attention because of their interesting properties. Nickel ferrite (NiFe2O4) nanocrystalline is one of the most important ferrites among other ferrites because of most promising applications in storage devices, microwave devices, gas sensors, ferrofluids, catalysts and adsorbent. The NiFe2O4 nanocrystalline has been synthesized by various methods such as co-precipitation, sonochemical process, polymeric precursor techniques, mechanical alloying, sol–gel, pulsed wire discharge, shock wave, reverse micelles, hydrothermal and ultrasonically assisted hydrothermal processes.In this study NiFe2O4 nanoparticels have been prepared by co-precipitation method over active carbon. The composite nanosized NiFe2O4/active carbon has been used to remove a number of Azo dyes, such as Alizarine Yellow R and Methyl Orange, from water. The study showed that this composite has a high adsorptive activity for these dyes and its tendency for removal of anionic dye and cationic azo dye was higher than the other. The effect of pH on the rate of the adsorption of the dyes by this ferrite composite was also investigated. The adsorption of these azo dyes on free active carbon and free nanoscaled NiFe2O4 was also examined and compared with that of NiFe2O4/ active carbon composite. The obtained results revealed that this composite is a superior adsorbent compared with either NiFe2O4 or active carbon alone.
Abstract: Much attention has been paid on nanomaterials in recent years due to their fundamental and technological applications. The physical and chemical properties of nanomaterials have been enhanced because of their surface-to-volume ratio. Spinel ferrite with the general formula of MFe2O4 (M is a divalent cation) have attracted much attention because of ...
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