فهرست مطالب

Physical Chemistry & Electrochemistry - Volume:5 Issue:1, 2017
  • Volume:5 Issue:1, 2017
  • تاریخ انتشار: 1396/04/03
  • تعداد عناوین: 6
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  • Davood Kaviani, Majid Saghi, Maryam Agha Mohammadi, Mohammad Hosein Bigtan Pages 149-154
    The studies performed about electrochemical oxidation 2-amino-4-methylphenol indicate that ortho-quinone yielded through oxidation of this chemical compound was unstable and it could be used as Michael acceptor under solvent influences, carrier electrolyte, additives and could be transformed into the various compounds in the form of 1-4 addition Michael reaction. Based on this, in the paper firstly electrochemical oxidation of 2-amino-4-methylphenol in the water has been studied. Then the electrochemical behavior of the compound has been assessed in the presence of nucleophile Penicillin amine under different conditions. The studies indicate that the above compounds could be transformed to new derivatives in the presence of Penicillin amine and phosphate buffer with concentration of 0.2 M and pH=7 during the EC mechanism. Using electrochemical data obtained by performing studies, electrolysis of 2-amino-4-methylphenol has been made in the presence of Penicillin amine, which is served as nucleophile and the product has been yielded with suitable practical efficiency. In all cases in order to optimize the electrolysis conditions and to determine the mechanism, cyclic voltammetry (CV) and Controlled Potential Coulometer (CPC) were utilized.
    Keywords: 2-amino-4-methylphenol, Electrochemical, Penicillin amine, Voltammetry Technique
  • Seyyed Mostafa Hosseini Pages 155-164
    calculate some thermodynamic properties of molten polymers including specific volume and isothermal compressibility (S.M. Hoseini, Physical Chemistry & Electrochemistry, 2 (2014) 56-65). This work extended that EOS to predict the volumetric properties of some molten ethylene copolymers including ethylene/1-octene, ethylene/1-butene (xethylene equal to 0.8543 and 0.563), ethylene/propene. The ability of the extended EOS was checked by comparing the results with 738 literature data points for the specific volumes over the temperature range from 422.35-505.89 K and pressure range from 0.1 up to 200 MPa. The average absolute deviation (AAD) of the calculated specific volumes from literature data was found to be 1.12%. The isothermal compressibility coefficients, κT have also been predicted using ISM EOS. From 180 data points examined, the AAD of estimated κT was equal to 8.48%. Our calculations on the volumetric and thermodynamic properties of studied copolymers reproduced the literature data with reasonably good accuracy.
    Keywords: Equation of state, Copolymer melts, Thermodynamic properties
  • Elham Eslami, Fatemeh Farjam Pages 165-171
    We used an effective electrochemical sensor for the determination of imipramine at pH 7.2 using a carbon nanocomposite electrode. The electrode has been designed by incorporation of montmorillonite nanoclay into the carbon ionic liquid electrode. The high sensitivity of 1.714 μA (μM)-1, two linear calibration ranges of 0.1–2 μM and 2-40 μM, and detection limit of 19 nM were achieved. The relative standard deviations (RSDs) were 2.73% (n=7, 2 μM), 2.97% (n=4, 2 μM), respectively. Thus, this modified electrode was further applied to the determination of imipramine in urine sample.
    Keywords: Carbon ionic liquid electrode, Electrochemical sensor, Imipramine, Montomorillonite Nanoclay
  • Seyyed Mostafa Hoseini Pages 173-178
    The present work is the successful extension of an improved equation of state (EOS) to refrigerant fluids. The objective is the prediction of isothermal and saturated liquid densities of refrigerants. Two temperature-independent parameters appearing in the modified EOS are closely related to critical point properties of refrigerant fluids. Our results showed that, the proposed EOS can predict well isothermal and saturated liquid destinies of studied refrigerants over the temperature range from 100-400 K and pressures up to187 MPa, with AADs equal to 2.16% and 2.66%, respectively. The surface tensions and sound velocities of saturated refrigerants were also estimated through the simple relations with AADs equal to 4.76% and 5.66%.
    Keywords: Equation of state, Refrigerant, Speed of sound
  • Aiyoub Parchehbaf Jadid, Mostafa Pourjafar Pages 179-186
    In this study, Taguchi experimental design has been used for the optimization of thickness of chromium layers. For this purpose brass materials have been electroplated under various conditions of the process. An orthogonal array (OA) was employed to analyze the effect of plating parameters on the characteristic of the thickness. Variables which were considered for working were as following; amount of chromic acid, amount of sulfuric acid, time, and current density. Eventually, the obtained results revealed that among the influential parameters in the process, only current density of 6A/dm2 and time of 4 minutes have the most effect on the enhancement of the thickness.
    Keywords: thickness, Electroplating, Decorative Chromium, Taguchi Method, Experimental Design
  • Ramineh Medhat, Mahmoud Pakshir, Khashayar Morshed Behbahani, Pooria Najafisayar Pages 187-196
    In this study, the effects of forming method (extrusion) and environmental factors (solution pH and temperature) on the corrosion performance of AZ91 magnesium alloys were investigated using potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM) and salt spray techniques. The polarization test results of the specimens showed that simple shear extrusion (SSE) process have adverse effect on the samples corrosion behavior in 3.5 wt% NaCl solution and corrosion current densities increased by increasing temperature/ decreasing pH of the solution. Moreover, the EIS test results showed that the increase in temperature or acidity of the solution led to decrease in charge-transfer resistance (Rct) at the electrode/solution interface for both as-cast and SSEed samples. In addition, the weight loss measurements, based on the salt spray test results, revealed that normally extruded samples have better corrosion performance than as-cast and SSEed ones which is in accordance with the electrochemical test results.
    Keywords: AZ91 magnesium alloy, Simple shear extrusion, Corrosion, Electrochemical impedance spectroscopy, Potentiodynamic test