Nanochemistry
Jamal Afzali; Sedigheh Sadegh Hassani
Volume 3, Issue 3, pp. 180-282,Serial No. 8 , July 2015, , Pages 266-275
Abstract
Magnetic force microscope ( MFM ) is a powerful technique for mapping the magnetic force gradient above the sample surface. Herein, single-wall carbon nanotubes (SWCNT) were used to fabricate MFM probe by dielectrophoresis method which is a reproducible and cost-effective technique. The effect of induced ...
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Magnetic force microscope ( MFM ) is a powerful technique for mapping the magnetic force gradient above the sample surface. Herein, single-wall carbon nanotubes (SWCNT) were used to fabricate MFM probe by dielectrophoresis method which is a reproducible and cost-effective technique. The effect of induced voltage on the deposition manner of carbon nanotubes (CNT) on the atomic force microscope ( AFM ) tip was investigated . The optimum voltage and frequency of SWCNT solution are obtained as 13 volts and 2 MHz, respectively. After coating theas-prepared CNT tips with a layer of cobalt,it can be used to obtain high resolution MFM images.
Nanochemistry
Meysam Sadeghi; Sina Yekta; Mirhassan Hosseini; Mohammad javad Taghizadeh
Volume 3, Issue 2, pp. 72-147, Serial No. 7 , April 2015, , Pages 105-113
Abstract
In the present study, tenorite (CuO) nanoparticles have been assayed for their catalytic properties. The decontamination reaction of chloro ethyl ethyl sulfide (CEES) as an surrogate of sulfur mustard simulant have been accomplished on the surface of CuO NPs with different weight ratios at ambient temperature ...
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In the present study, tenorite (CuO) nanoparticles have been assayed for their catalytic properties. The decontamination reaction of chloro ethyl ethyl sulfide (CEES) as an surrogate of sulfur mustard simulant have been accomplished on the surface of CuO NPs with different weight ratios at ambient temperature and monitored by Gas chromatography equipped with Flame ionization detector (GC-FID) and Gas chromatography coupled with a mass spectroscopy (GC-MS). CuO NPs were successfully synthesized via precipitation method in the absence and presence of polyvinylpyrrolydone (PVP) and copper (ΙΙ) nitrate as the precursors. PVP was used as a capping agent to control and reduce the agglomeration of the nanoparticles. The synthesized CuO NPs were characterized by Scanning electron microscopy (SEM), Transmission electron microscopy (TEM) and X-ray diffraction (XRD) techniques. The GC analysis results has revealed that the decontamination of CEES occurred in n-hexane solvent with the weight ratio of 1:40 (CEES: CuO NPs) after 12 h with more than 90% yield. The hydrolysis product such as hydroxyl ethyl ethyl sulfide (HEES) was also identified by GC-MS analysis.
Analytical chemistry
Masoumeh Taei; Foroozan Hasanpour; Marjan Shavakhi
Volume 3, Issue 1, pp. 1-71, Serial No.6 , January 2015, , Pages 16-25
Abstract
A carbon-paste electrode (CPE) chemically modified with the N-4,4'-azodianiline(ferrocenyl Schiff base) complex and multi wall carbon nanotubes (ADAFCNTE) was used as a highly sensitive electrochemical sensor for determination of trace amounts of atenolol. The oxidation peak potentials in cyclic voltammogram ...
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A carbon-paste electrode (CPE) chemically modified with the N-4,4'-azodianiline(ferrocenyl Schiff base) complex and multi wall carbon nanotubes (ADAFCNTE) was used as a highly sensitive electrochemical sensor for determination of trace amounts of atenolol. The oxidation peak potentials in cyclic voltammogram of ADAFCNTE occurred around 550 mV vs Ag/AgCl (at pH 6.0) while this peak potential at the carbon paste electrode appeared around 800 mV at the same scan rate of 10 mV s−1. The kinetic parameters such as electron transfer coefficient, α, and rate constant for chemical reaction between atenolol and redox sites in modified electrode were 0.41 and 2.8×102 cm3 mol-1 s-1, respectively. The catalytic peak current was linearly dependent on atenolol concentration in the range of 0.1-57.0 µmol L-1 with a detection limit of 0.08 µmol L-1. Finally, the sensor was examined as a selective, simple and precise new electrochemical sensor for the determination of atenolol in urine samples, with satisfactory results.
Inorganic chemistry
Mahdieh Ghobadifard; Qasem Maleki; Mostafa Khelghati; Ehsan Zamani; Saeid Farhadi; Alireza Aslani
Volume 3, Issue 1, pp. 1-71, Serial No.6 , January 2015, , Pages 26-40
Abstract
ZnO nanostructures of different methods and sizes were grown in a controlled manner using a simple hydrothermal and sonochemical technique. Controlling the content of concentration and temperature of the reaction mixture, spherical nanoparticles ZnO structures could be synthesized at temperatures 100-150 ...
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ZnO nanostructures of different methods and sizes were grown in a controlled manner using a simple hydrothermal and sonochemical technique. Controlling the content of concentration and temperature of the reaction mixture, spherical nanoparticles ZnO structures could be synthesized at temperatures 100-150 °C with excellent reproducibility in solvothermal and at different power and time in sonochemical methods. These ZnO nanostructures have been tested for CO2 gas monitoring by depositing them as thick films on an inter-digitated alumina substrate and evaluating the surface resistance of the deposited layer as a function of operating temperature and CO2 concentrations. The gas sensitivity tests have demonstrated that the ZnO nanostructures, spherical morphology, exhibit high sensitivity to CO2 proving their applicability in gas sensors. The role of the nanostructure on the sensing properties of ZnO is also discussed.
Analytical chemistry
Mohamad Mohsen Momeni; Mohadesah Hakimiyan; Ali Kazempoor; Mahboubeh Mirhosseini; Zohre Nazari; Seyed Mostafa Mirhoseini; Hadi Kargar
Volume 3, Issue 1, pp. 1-71, Serial No.6 , January 2015, , Pages 41-47
Abstract
Cupper Oxide structures with a variety of novel morphologies are synthesized using cupper foil as substrate via a solution route. The structure, morphology and phase of the as-synthesized nanostructures are analyzed by various techniques. SEM images show gradual development of hierarchical structures ...
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Cupper Oxide structures with a variety of novel morphologies are synthesized using cupper foil as substrate via a solution route. The structure, morphology and phase of the as-synthesized nanostructures are analyzed by various techniques. SEM images show gradual development of hierarchical structures of copper oxide with different morphology. In order to study the effect of reaction time and temperature on the morphology of the CuO samples, experiments carried out at temperatures 0 °C and 25 °C for 10 min up to 12h. Results showed that the prepared samples exhibited some novel morphology such as nanorods, nanosheets, microflowers, Cubic shaped structures and Tulip flower-shaped structures.
Organic chemistry
Parya Nasehi; Alireza Kiasat; Mohammad Kazem Mohammadi
Volume 2, Issue 3, pp. 162-231, Serial No. 4 , July 2014, , Pages 180-186
Abstract
3,4-dihydropyrimidin-2(1H)-thiones were synthesized in the presence of Ag nanoparticle/melamine sulfonic acid (MSA) supported on silica gel. The reaction was carried out at 110 oC for 20 min under solvent free conditions. In all cases, the three component reaction proceeded smoothly to give the corresponding ...
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3,4-dihydropyrimidin-2(1H)-thiones were synthesized in the presence of Ag nanoparticle/melamine sulfonic acid (MSA) supported on silica gel. The reaction was carried out at 110 oC for 20 min under solvent free conditions. In all cases, the three component reaction proceeded smoothly to give the corresponding 3,4-dihydropyrimidin-2(1H)-thiones in moderate to good yield. We have found the best conditions are using 0.2 g MSA, 0.05 g Ag nanoparticle.SiO2 under solvent free conditions at 110 oC. This method have some advantages such as good yield, mild reaction conditions, ease of operation and work up, short reaction time and high product purity. In this work, we have investigated the application of Ag nanoparticle/MSA.SiO2 for synthesis of Biginelli – type condensation.
Nanochemistry
Mahdi Rezaei Sameti; Nina Alisafarzadeh
Volume 2, Issue 3, pp. 162-231, Serial No. 4 , July 2014, , Pages 209-221
Abstract
The aim of this research is studying the effects of Ge-doped on CO adsorption on the outer and inner surfaces of (6, 0) zigzag model of boron nitride nanotube (BNNTs) by using DFT theory. For this purpose, eight models of CO adsorption on the surfaces of BNNTs are considered. At first step, all structures ...
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The aim of this research is studying the effects of Ge-doped on CO adsorption on the outer and inner surfaces of (6, 0) zigzag model of boron nitride nanotube (BNNTs) by using DFT theory. For this purpose, eight models of CO adsorption on the surfaces of BNNTs are considered. At first step, all structures were optimized at B3LYP and 6-31G (d) standard base set and then the electronic structure, adsorption energy, HOMO - LUMO orbitals, gap energy, quantum molecular descriptors, and NQR parameters were determined. The bond lengths neighborhood sites of Ge-doped of BNNTs at all models were increased and the bond angles decreased. The small adsorption energy value and large interaction distance show that the adsorption of CO on BNNTs is weakly physical adsorption due to weak Van der Waals interaction. Our calculated results show that the adsorption of CO on the surface of undoped models is more favorable than Ge-doped models. The NQR parameters of the first layer in all the models are larger than those other layers.
Analytical chemistry
Behnam Hafezi
Volume 2, Issue 3, pp. 162-231, Serial No. 4 , July 2014, , Pages 222-231
Abstract
In this work, a tracer study on pore initiation in anodic alumina in oxalic acid was performed. Effects of some experimental parameters such as applied electrical potential, electrolyte composition and heat pretreatment were evaluated. Electrochemical and morphological experiments were performed using ...
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In this work, a tracer study on pore initiation in anodic alumina in oxalic acid was performed. Effects of some experimental parameters such as applied electrical potential, electrolyte composition and heat pretreatment were evaluated. Electrochemical and morphological experiments were performed using potentiostatic anodizing and scanning electron microscopy (SEM) techniques, respectively. Effect of electrolyte composition on current density was discussed. In various electrical potentials, electrolyte composition had different effects on current density. Addition of sulfuric acid into oxalic acid increased porosity. Also, distribution of pore size and pore diameter were influenced by presence of sulfuric acid. Effect of electrolyte composition on the morphology of aluminum surface layer was depended on to the electric potential. Current density and porosity of aluminum surface layer was decreased by heat pretreatment.
Analytical chemistry
Rasoul Pourtaghavi Talemi; Sajjad Bakhtiari; Nabi Javadi; Morteza Vatanparast
Volume 2, Issue 2, pp. 82-163, Serial No. 3 , April 2014, , Pages 93-105
Abstract
In the present study, we investigate the potentiometric behavior of Cu2+ carbon paste electrodes based on two mercapto compounds 2-Ethylmino-5-Mercapto-1,3,4-Thiadiazole (EAMT) and 2-Acetylamino-5-mercapto-1,3,4-thiadiazole (AAMT) self-assembled on gold nano-paricle (GNP) as ionophore. Then, the results ...
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In the present study, we investigate the potentiometric behavior of Cu2+ carbon paste electrodes based on two mercapto compounds 2-Ethylmino-5-Mercapto-1,3,4-Thiadiazole (EAMT) and 2-Acetylamino-5-mercapto-1,3,4-thiadiazole (AAMT) self-assembled on gold nano-paricle (GNP) as ionophore. Then, the results obtained from the modified electrodes are compared. The self-assembled ionophores exhibit a high selectivity for Copper ion (Cu2+), in which the sulfur and nitrogen atoms in their structure play a role as the effective coordination donor site for the Copper ion. Among these electrodes, the best performance was obtained with the sensor with a EAMT/graphite powder/paraffin oil weight ratio of 4.0/68/28 with 200 µL of GNP exhibits the working concentration range of 1.6×10−9 to 6.3×10−2 M and a Nernstian slope of 28.9±0.4 mVdecade−1 of copper (II) activity. The detection limit of electrode was 8.9(±0.2)×10−10 M and potential response was pH independent across the range of 2.8–6.3. The proposed electrode presented very good selectivity and sensitivity towards the Cu2+ ions over a wide variety of cations including alkali, alkaline earth, transition and heavy metal ions. Also the proposed electrode was successfully applied as an indicator electrode in the potentiometric titration of Cu (II) ions with EDTA and the potentiometric determination of copper ions in spiked water samples.
Nanochemistry
Hojat Veisi; Davood Kordestani; Sami Sajjadifar; Mona Hamelian
Volume 2, Issue 1, pp. 1-81, Serial No. 2 , January 2014, , Pages 27-33
Abstract
An efficient synthetic method for successful synthesis of amine denderon on SBA-15 and related Pd (II) complex has been developed. This modified mesoporous material was characterized by various techniques such as TEM, XRD, atomic absorption spectroscopy, N2 adsorption-desorption, and FT-IR. The catalytic ...
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An efficient synthetic method for successful synthesis of amine denderon on SBA-15 and related Pd (II) complex has been developed. This modified mesoporous material was characterized by various techniques such as TEM, XRD, atomic absorption spectroscopy, N2 adsorption-desorption, and FT-IR. The catalytic activities of the prepared catalysts were investigated by employing aerobic oxidation of alcohols as model reactions. The yields of the products were in the range from 75% to 92%. The catalyst can be readily recovered and reused at least 5 consecutive cycles without significant leaching and loss its catalytic activity. Organosuperbase, SBA-15, Palladium complex, Oxidation Organosuperbase, SBA-15, Palladium complex, Oxidation
Nanochemistry
Sharmin Esmaeilpoor; Zahra Shirzadi; Hadi noorizadeh
Volume 2, Issue 1, pp. 1-81, Serial No. 2 , January 2014, , Pages 56-71
Abstract
The quantitative structure-retention relationship (QSRR) of nanoparticles in roadside atmosphere against the comprehensive two-dimensional gas chromatography which was coupled to high-resolution time-of-flight mass spectrometry was studied. The genetic algorithm (GA) was employed to select the variables ...
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The quantitative structure-retention relationship (QSRR) of nanoparticles in roadside atmosphere against the comprehensive two-dimensional gas chromatography which was coupled to high-resolution time-of-flight mass spectrometry was studied. The genetic algorithm (GA) was employed to select the variables that resulted in the best-fitted models. After the variables were selected, the linear multivariate regressions [e.g. the partial least squares (PLS)] as well as the nonlinear regressions [e.g. the kernel PLS (KPLS) and Levenberg- Marquardt artificial neural network (L-M ANN)] were utilized to construct the linear and nonlinear QSRR models. The correlation coefficient cross validation (Q2) and relative error for test set L-M ANN model are 0.939 and 4.89, respectively. The resulting data indicated that L-M ANN could be used as a powerful modeling tool for the QSPR studies.
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