Islamic Azad University at Gorgan
Gorgan, Iran
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Tazikeh-Lemeski E.,Islamic Azad University at Gorgan
Journal of Molecular Structure | Year: 2017

We investigated the adsorption ability of NH3 molecule on the outer surfaces of Al12N12, Al16N16, and Al12CN11 nano-cages using density functional theory (DFT) and time-dependent density functional theory (TD-DFT) calculations. The calculations represent that the NH3 molecule can be chemically adsorbed on the top of aluminum atoms in Al12N12 and Al16N16 nano-cages with the energies of −1.38 and −1.30 eV, respectively, indicating that the nature of these interactions are of the covalent characteristic. After the NH3 adsorption on the Al12CN11, the electronic and optical properties of the nano-cage and the atomic charge in the some of the nearby Al and N atoms around C atom was dramatically changed. Thus, the Al12CN11 can be utilized as a novel material for the detection of NH3 molecule owing to significant changes observed in their electrical conductivity. © 2017 Elsevier B.V.

An efficient and green protocol for the synthesis of functionalised spirooxindole derivatives is described. This involves the reaction of in situ-generated keto-enaminones with N-alkylisatins in the presence of isothiocyanates. © 2017, Science Reviews 2000 Ltd. All rights reserved.

Golsefidi M.A.,Islamic Azad University at Gorgan | Sarkhosh B.,Islamic Azad University at Gorgan
Journal of the Iranian Chemical Society | Year: 2017

Effective procedure to synthesize Fe3O4@SiO2@TiO2–Sn magnetically separable photocatalyst by a combination of co-precipitation, sol–gel and photodeposition methods was introduced. Products were characterized by XRD, SEM, VSM, EDS, DRS, TEM, ICP-OES and IR techniques. The dimensions of catalyst particle size were evaluated by scanning electron microscopy, and results approved nanoscale size for product. In addition, studying the magnetic nature by VSM analysis showed superparamagnetic properties for all samples. XRD pattern indicates that TiO2 coated on Fe3O4@SiO2 core well crystallized at 400 °C in anatase phase. Synthesized photocatalyst shows good photocatalytic performance in decolorization of rhodamine B aqueous solution. The composite nanoparticles showed high recycling efficiency and stability over five separation cycles. © 2017, Iranian Chemical Society.

Mirmehdi S.M.,Gorgan University of Agricultural Sciences and Natural Resources | Zeinaly F.,Islamic Azad University at Gorgan | Dabbagh F.,Gorgan University of Agricultural Sciences and Natural Resources
Composites Part B: Engineering | Year: 2014

The effect of the filler content and the different type of wood flour on the mechanical properties of polyethylene composites filled with an agricultural pruning residue, date palm wood flour (DPWF) was studied. The different types of DPWF were rachis, leaflet and leaf, resulting from that annual pruning of date palm tree. Composites were made at 45%, 60% and 75% by weight wood flour contents. The particle size was 25-40 mesh and Maleic Anhydride modified polyethylene was also added at 2% of total weight of each board. First, the palletized feedstock from DPWF and plastic were provided by a twin screw extruder and then, the compound pellets ground and the final boards were made of them by a hot-press. It was observed that by increasing the filler content, the mechanical properties, flexural strength (MOR) and tensile strength decreased, while the flexural modulus (MOE) increased. The tensile strength did not show significant differences as a function of the filler type while the flexural strength and the flexural modulus of the boards made from leaflet flour, was the highest. © 2013 Published by Elsevier Ltd.

Peyghan A.A.,Islamic Azad University at Tehran | Soltani A.,Islamic Azad University at Gorgan | Pahlevani A.A.,Islamic Azad University at Gorgan | Kanani Y.,Islamic Azad University at Gorgan | Khajeh S.,Payame Noor University
Applied Surface Science | Year: 2013

First-principles computations have been applied to scrutinize the adsorption behavior of CO molecule on the external surface of H-capped aluminum- and gallium-doped (6, 0), (8, 0) zigzag and (5, 5) armchair single-walled BN nanotubes (SWBNNTs). Binding energy corresponding to the most stable configuration of CO on the gallium-doped (6, 0) BNNT is found to be -0.83 eV, which is high typical sensitivity to CO molecule. Our results indicate that both Al- and Ga-doping can notably enhance the adsorption energy of CO/BNNTs complexes. Our electronic results reveal that there is a notable orbital hybridization among two species in adsorption process being an evidence of strong interaction. For the CO/BNNTs complexes, the energy gaps, NBO, dipole moments, natural atomic orbital occupancies and global indices are computed. Finally, we reported a novel type of toxic gas sensor that can be used for detecting the presence of CO molecule. © 2012 Elsevier B.V.

Soltani A.,Islamic Azad University at Gorgan | Peyghan A.A.,Islamic Azad University at Tehran | Bagheri Z.,Islamic Azad University at Tehran
Physica E: Low-Dimensional Systems and Nanostructures | Year: 2013

We have performed a comparative density functional theory study on adsorption of hydrogen peroxide (H2O2) on the boron nitride and silicon carbide nanotubes (BNNT and SiCNT) in terms of energetic, geometric, and electronic properties. It has been found that the molecule is chemically adsorbed on both of the tubes so that its interaction with SiCNT (adsorption energy ∼-0.97 eV) is much stronger than that with BNNT (adsorption energy ∼-0.47 eV). The H2O2 adsorption on BNNT slightly decreases its work function, increasing the field electron emission from the BNNT surface while it may not affect that of the SiCNT. In addition, the adsorption process may increase the electrical conductivity of SiCNT while does not affect that of the BNNT, significantly. We believe that the SiCNT may be a potential candidate for detection of H2O2. © 2013 Elsevier B.V. All rights reserved.

Mahmoudian M.R.,University of Malaya | Mahmoudian M.R.,Islamic Azad University | Alias Y.,University of Malaya | Basirun W.J.,University of Malaya | And 2 more authors.
Electrochimica Acta | Year: 2012

This study examines the preparation of ultra-thin polypyrrole nanosheets decorated with Ag nanoparticles (Ag-UTPNSs) and their application in the enzyme-less detection of hydrogen peroxide (H 2O 2) detection. The X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) results confirmed that Ag nanoparticles (NPs) were deposited onto the surface of the UTPNSs. The increase of the H 2O 2 reduction current peak to 120 μA in the presence of the Ag-UTPNS/glassy carbon electrode (GCE) as compared to the UTPNS/GCE indicates that the sensitivity of the electrode to H 2O 2 is significant. This observation can be explained by the larger surface area of the UTPNSs, which can increase the interactions between the polymer and the AgNO 3 solution during the deposition of the Ag NPs, and by the small size of the deposited Ag NPs, which can produce a surface area of Ag that is suitable for the reaction with H 2O 2. The amperometric responses show that the limit of detection, the limit of quantification (S/N = 3) and the sensitivity are estimated to be 0.57 μM, 1.93 μM and 4.477 μA mM -1, respectively, for the linear segment. The results of the reproducibility experiments show that the use of Ag-UTPNS/GCE is feasible for the quantitative detection of certain concentration ranges of H 2O 2. © 2012 Elsevier Ltd.

Golsefidi M.A.,Payame Noor University | Golsefidi M.A.,Islamic Azad University at Gorgan | Es'haghi Z.,Payame Noor University | Sarafraz-Yazdi A.,Ferdowsi University of Mashhad
Journal of Chromatography A | Year: 2012

In this study, a simple preparation approach was developed for modified bisphenol A (BPA) molecularly imprinted polymer sorbent used in the hollow fiber solid phase microextraction (MIP-HF-SPME) of chlorogenic acid (CGA). The pre-polymer solution containing the template was introduced into the polypropylene hollow fiber segment for in situ polymerization. MIP-HF-SPME conditions based on the modified MIP-sorbent were optimized. Finally, the tool was used for selective extraction of chlorogenic acid in Echinacea purpurea, a medicinal plant. Main parameters affecting synthesis of organic-inorganic hybrid MIP and microextraction procedure were investigated and optimized. The measurements were done under the optimal conditions. The limit of detection has been gained 0.08. ng/mL. The linear range and relative standard deviation (RSD %) are 0.2-1000. ng/mL and 0.38 (n= 3) respectively. The average relative recoveries of spiked analyte in the four concentration levels were between 84.8 and 97.2%. © 2012 Elsevier B.V.

Tazikeh-Lemeski E.,Islamic Azad University at Gorgan
Journal of Theoretical and Computational Chemistry | Year: 2016

In this study, we estimated the optimum concentration of copper ions that are effective in the stability and the structural changes of human growth hormone (hGH) protein in the combination of different concentrations of these ions at the molecular level using molecular dynamics simulation by Gromacs 4.6.5 software. Moreover, to estimate the binding affinity of copper ions to hGH protein, binding free energies is calculated by the molecular mechanics Poisson–Boltzmann Surface Area (MM-PBSA). The analysis of molecular dynamics (MD) trajectories as dictionary of the secondary structure of protein (DSSP), solvent accessible surface area (SASA) and binding free energy calculations show that hGH protein structure is more stabilized by increasing a limited concentration of copper ions. These findings align with our previous experimental studies. © 2016 World Scientific Publishing Company

Moradi A.V.,Islamic Azad University at Gorgan
Chemistry of Heterocyclic Compounds | Year: 2015

(Forumula presented) The N-(1,3-oxathiol-2-ylidene)carboxamides have been synthesized in excellent yield in the reaction between alkyl bromide, acid chloride, and ammonium thiocyanate in the presence of catalytic amount of ZnO nanosheets (15 mol %) in water as a solvent at room temperature. The separation of product from the reaction mixture is very simple. Using NS-ZnO as a catalyst considerably improves the yield of the desired product in comparison with performing these reactions without catalyst. The catalyst shows good reusability. © 2015 Springer Science+Business Media New York.

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