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Mokhtari B.,Islamic Azad University at Shahreza | Pourabdollah K.,Islamic Azad University at Shahreza
Journal of the Electrochemical Society | Year: 2012

Four proton di-ionizable diacid conformers of cone 25,27-di(carboxymethoxy) calix4arene-crown-5, 1,3-alternate 25,27-dicarboxymethoxy-calix4arene-crown-5, cone 25,27-biscarboxymethoxycalix4arene-crown-6 and 1,3-alternate 25,27-dicarboxymethoxy-calix4arene-crown-6 were synthesized and their binding abilities toward alkali and alkaline earth metals as well as some lanthanides were studied by means of differential pulse voltammetry. The novelty of this study was investigation of those nano-baskets by voltammetric behavior of two acidic moieties in each scaffold during complexation of the crown ether ring. Their voltammetric behavior was closely related to the complex formation by entrapment of the cation into the crown ether cavity and ion-dipole interaction between cation and acidic moieties in calixcrowns. The results revealed the selective changes in voltammetric behavior of synthesized scaffolds toward the cations. Moreover, the position of crown ether in 1,3-alternate instead of cone enhanced the domain of binding ability to more cations. Furthermore, it was shown that those carboxylic acid moieties, which were far from the crown ether ring in the 1,3-alternate, were not affected by encapsulated cations in the coordination space of crown ether and showed no voltammetric response. © 2011 The Electrochemical Society.

Nezamzadeh-Ejhieh A.,Islamic Azad University at Shahreza | Moazzeni N.,Islamic Azad University at Shahreza
Journal of Industrial and Engineering Chemistry | Year: 2013

Photocatalytic activity of CuS incorporated into an Iranian clinoptilolite (CuS-Cp) was studied for decolorization of a mixture of Methyl Orange and Bromocresol Green under sunlight irradiation. All samples were characterized by XRD, FTIR, DRS and TG/DTG techniques. The effect of some key experimental parameters such as: amount of the catalyst (0.05-5gL-1), initial concentration of dyes (5-30mgL-1), solution pH (1-11) and also dosage of H2O2 and KBrO3 was studied on the decolorization extent. The extent of decolorization was estimated from the residual concentration by spectrophotometrically and it was confirmed by the reduction of chemical oxygen demand (COD). © 2013 The Korean Society of Industrial and Engineering Chemistry.

Nezamzadeh-Ejhieh A.,Islamic Azad University at Shahreza | Amiri M.,Islamic Azad University at Shahreza
Powder Technology | Year: 2013

CuO as a semiconductor as incorporated onto an Iranian natural Clinoptilolite zeolite, was prepared by calcination of Cu(II)-ion exchanged Clinoptilolite. The obtained composite was used as a photocatalyst to degrade a p-aminophenol aqueous solution. All raw and modified samples were characterized using XRD, FT-IR, BET and SEM methods. The degradation and mineralization extents were performed by UV-vis spectrophotometry, COD and HPLC. The optimum values of the experimental parameters which affect the degradation efficiency were obtained as: 2.0gL-1 of the photocatalyst, 20ppm of p-aminophenol and pH 6.0. Hydrogen peroxide and potassium bromate considerably increased the rate of degradation. Zeolite bed had considerable role in the photodegradation efficiency, so the proposed catalyst significantly increased the efficiency with respect to CuO and especially Clinoptilolite alone. © 2012 Elsevier B.V.

Nezamzadeh-Ejhieh A.,Islamic Azad University at Shahreza | Kabiri-Samani M.,Islamic Azad University at Shahreza
Journal of Hazardous Materials | Year: 2013

In this work an Iranian natural clinoptilolite tuff was pre-treated and changed to the micro (MCP) and nano (NCP) particles by mechanical method. Modification of micro and nano particles and also their Ni-exchanged forms were done by dimethylglyoxime (DMG). The raw and modified samples were characterized by XRD, FT-IR, SEM, BET, TG-DTG and energy dispersive analysis X-ray spectroscopy (EDAX). Removal of Ni(II) by modified and unmodified samples was investigated in batch procedure. It was found that NCP-DMG has higher capacity for removal of Ni(II). The effects of analytical parameters such as pH, dose of DMG, concentration of nickel solution, contact time and selectivity were studied and the optimal operation parameters were found as follows: pHPZC: 7.6, CNi(II): 0.01M, contact time: 360min and DMG dosage: 5mM. The results of selectivity experiments showed that the modified zeolite has a good selectivity for nickel in the presence of different multivalent cations. Langmuir and Freundlich isotherm models were adopted to describe the adsorption isotherms. Adsorption isotherms of Ni(II) ions could be best modelled by Langmuir equation, that indicate the monolayer sorption of Ni(II). Comparison of two kinetic models indicates that the adsorption kinetic can be well described by the pseudo-second-order rate equation that indicates that the rate limiting step for the process involves chemical reaction. The negative δH and δG indicate an exothermic and spontaneously process. The negative δS indicates that the adsorption of nickel cations from solution occurs with lower amount ion replacement, thus chemisorptions due to complex formation are dominant process in nickel removal. © 2013 Elsevier B.V.

Nezamzadeh-Ejhieh A.,Islamic Azad University at Shahreza | Shirzadi A.,Islamic Azad University at Shahreza
Chemosphere | Year: 2014

Photodegradation of tetracycline (TC) aqueous solution by FeO doped onto nano-clinoptilolite particles was investigated using a high pressure Hg lamp as radiation source. Nano-particles of clinoptilolite were prepared using ball-milling of micro crystals of zeolite. The pretreated nano-particles ion exchanged in a ferrous solution and the Fe(II)-exchanged form was calcined at 450. °C. All samples were characterized by FT-IR, DRS, SEM and XRD. The degradation extent was determined via UV-Vis absorption spectroscopy and COD. Based on the study of the effect of key operating parameters, the optimal conditions were determined to reach the higher efficiency of the process. The best photocatalytic activity was obtained in presence of the catalyst containing 5.4% FeO. © 2014 Elsevier Ltd.

Nezamzadeh-Ejhieh A.,Islamic Azad University at Shahreza | Hashemi H.-S.,Islamic Azad University at Shahreza
Talanta | Year: 2012

A novel zeolite modified electrode for use in voltammetric determination of l-cysteine (CySH) was described. The electrode comprises a Co(II)-exchanged zeolite Y as modifier in carbon paste matrix. First, the electrochemical behavior of Co(II) in modified carbon paste electrode was studied. The results demonstrated that diffusion can control the redox process of cobalt cations at the surface of the modified electrode. Then, the behavior of the electrode in the presence of CySH was studied by using cyclic voltammetry and a novel behavior was observed. In high concentration of CySH (above 10 mmol L -1), one pair of semi-reversible electrochemical extra peak was observed which was assigned to the processes of oxidation-reduction of CySH at the unmodified and modified electrode. Acidic conditions with respect to the neutral one cause an increase in the electrode response. The modified electrode showed a suitable linear calibration graph in the concentration range of 1.0 × 10 -9-1.0 × 10 -3 mol L -1 cysteine with a detection limit of 2.37 × 10 -10 mol L -1. The influence of potential interfering substances on the peak current was studied and the results showed that the method was highly selective for determination of CySH. Thus, the proposed electrode was used for the determination of CySH in real samples including human blood serum, urine, N-acetylcysteine tablet and powdered poultry feed and the satisfactory results were obtained. Typical features of the sensor can be summarized as: low cost, simple preparation, fast response, good stability and selectivity, wide linear range, low detection limit and high reproducibility. © 2011 Elsevier B.V. All rights reserved.

Nezamzadeh-Ejhieh A.,Islamic Azad University at Shahreza | Hushmandrad S.,Islamic Azad University at Shahreza
Applied Catalysis A: General | Year: 2010

Semiconductor photocatalysis has proved to be an efficient method for decolorization and degradation of pollutants. In this study, a common semiconductor, CuO, as doped with synthetic zeolite NaX via wet impregnation of parent zeolite with Cu(NO3)2 aqueous solution was prepared. The potential of the obtained photocatalyst in decolorization of methylene blue (MB) dye under sunlight irradiation was studied. Characterization of parent zeolite NaX and prepared samples were studied using X-ray powder diffraction (XRD) patterns, infrared spectroscopy (FT-IR) spectra, diffuse reflectance spectroscopy (DRS), thermo analytical techniques (TG/DTG and DSC), SEM and BET methods. The active component value (CuO) on parent zeolite was also determined by atomic absorption spectroscopy (AAS) method on digested catalyst. The influence of experimental parameters on the dye photodecolorization process was studied and it was observed that photoreactivity of photocatalyst (CuO/X) varied with the amount of catalyst, initial dye concentration, pH of the dye solution, temperature, and active component value (CuO) loading. The role of zeolite NaX as a support was also investigated on decolorization rate. The optimal experimental conditions were determined as follow: catalyst amount; 1.0 g L-1, concentration of the dye solution; 0.03 mM, pH of solution; 11, and active component value; 88 mg CuO per gram of the catalyst. Under these optimum conditions, the obtained decolorization efficiency for MB dye was 94%. The reusability of the intended catalyst was also investigated. © 2010 Elsevier B.V. All rights reserved.

Nezamzadeh-Ejhieh A.,Islamic Azad University at Shahreza | Karimi-Shamsabadi M.,Islamic Azad University at Shahreza
Applied Catalysis A: General | Year: 2014

The present study compares the photocatalytic decolorization ability of CuO as supported onto both micronized zeolite X (CuO/MX) and zeolite X nano-particles (CuO/NX) toward aqueous mixture of Methyl Orange (MO) and Methylene Blue (MB). Both photocatalysts were characterized by XRD, SEM, BET, FT-IR and DRS. The progress of the photodecolorization of the proposed mixture was monitored using UV-vis spectrophotometer. The decolorization of dyes was systematically studied by varying the experimental parameters in order to achieve maximum decolorization efficiency. Application of the Langmuir-Hinshelwood kinetics allowed calculating the photodecolorization rate constants. CuO/NX was more efficient than CuO/MX and also, MO was more degraded than MB. The reusability of the photocatalyts was also tested and the decolorization activities of 90% and 88% were respectively obtained for CuO/NX and CuO/MX after four recycles. © 2014 Elsevier B.V.

Ahmadian F.,Islamic Azad University at Shahreza
Journal of Alloys and Compounds | Year: 2013

Electronic structure calculations based on density functional (DFT) theory within the generalized gradient approximation (GGA) for the Ti2CoSn Heusler compound have been performed using the self-consistent full-potential linearized augmented plane wave (FPLAPW) method. The Ti2CoSn Heusler alloy was predicted to be a complete half-metal. The total magnetic moment of Ti2CoSn was obtained 3μB per formula unit for the equilibrium lattice parameter which is in agreement with Slater-Pauling rule Mtot = Ztot-18. The minority spin and spin-flip gaps were calculated equal to 0.87 eV and 0.47 eV, respectively. The spin-orbit interaction has a negligible contribution to the half-metallic and magnetic properties of Ti2-CoSb alloy. In addition, the band structure and density of states (DOSs) were studied and the origin of minority band gap was also discussed. The Ti2CoSn Heusler alloy maintains the half-metallic characteristic for lattice constants between 5.68 and 7.02 Å leading to be an interesting material in the field of spintronics. © 2013 Elsevier B.V. All rights reserved.

Nano-assisted inclusion separation of alkali metal cations from basic aqueous solutions was reported by inclusion-facilitated emulsion liquid membrane process. The novelty of this study is application of nano-baskets of calixarene in the selective and efficient separation of alkali metal cations as both the carrier and the surfactant. For this aim, four derivatives of p-tert-calix[4]arene bearing different sulfonamide moieties were synthesized and their inclusion-extraction parameters were optimized including the calixarene scaffold 3 (4. wt.%) as the carrier/demulsifier, the commercial kerosene as diluent in membrane, sulphonic acid (0.2. M) and ammonium carbonate (0.4. M) as the strip and the feed phases, the phase and the treat ratios of 0.8 and 0.3, mixing speed (300. rpm), and initial solute concentration (100. mg/L). The selectivity of membrane over more than ten interfering cations was examined and the results revealed that under the optimized operating condition, the degree of inclusion-extraction of alkali metal cations was as high as 98-99%. © 2012 Elsevier B.V..

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