فهرست مطالب

Scientia Iranica
Volume:28 Issue: 3, May-Jun 2021

  • Transactions on Chemistry and Chemical Engineering (C)
  • تاریخ انتشار: 1400/03/12
  • تعداد عناوین: 11
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  • A. A.Taherpour *, P. Gholami Keivanani, M. Jamshidi, S. Hatami, N. Zolfaghar Pages 1343-1352

    In this study, using the density functional theory (DFT) and time dependent density functional theory (TD-DFT) methods, the physical and chemical properties of the Thioridazineand fullerene C60 nano complex were studied. The most important goal was increasing C60 dipolar moment as a novel drug delivery system to carry Thioridazineand. Several descriptors were used in the ground state, including electrochemical properties based on the HOMO and LUMO orbital energy, hardness, softness, chemical potential, and Mulliken charge. The dipole moment of this nano-complex is about 2.61D, which indicates its moderate solubility in polar solvents. The UV-Vis spectrum obtained with the CAM-B3LYP method shows that the absorption spectrum has blue-shifted by about λ = 24 nm after formation of the complex. Based on the calculations in the excited state and the hole-electron theory in the first three modes, a photo-induced electron transfer (PET) phenomenon was observed at different absorption wavelengths for the complex. Using the Marcus theory of electron transfer, the free energy of activation for electron transfer and the free energy of electron transfer for all PETs were calculated.

    Keywords: photo-induced electron transfer, Thioridazine, DFT, Marcus theory
  • A. Saffarian Delkhosh, A. Vahid, S. Baniyaghoob *, M. Saber Tehrani Pages 1353-1365

    Heat-treated Gilsonite (HT-Gil) has been used for the adsorptive removal of toluene from wastewater. Characterization of the sample was carried out by utilizing appropriate standard test methods. The FT-IR spectrum indicates the presence of long aliphatic chains and aromatic rings. FE-SEM imaging is employed for investigating the surface morphology, the grain size of the sample and confirms the irregular shape of the HT-Gil with different particle size distributions. Determination of chemical properties and elemental composition of the sample was conducted according to several ASTM tests along with XRF analysis. Also, TGA experimental results revealed the thermal stability of the sample up to 350 °C. Optimization of adsorption parameters, including temperature (A: 5-45 °C), pH (B: 4-9), and contact time (C: 20-90 min) was performed by BBD. The results showed that the maximum adsorption capacity of 69.1% was achieved in the optimum condition containing 5 °C, pH 9, and 90 min. The spent adsorbent also has acceptable adsorption efficiency (62.12%) after four thermal regeneration cycles. Moreover, the results of equilibrium data were in accordance with the Freundlich isotherm model (R2 = 0.9531) and imply the non-uniformity of the adsorbent surface that is in line with those found previously in the literature.

    Keywords: Adsorption, Toluene, Experimental design, Gilsonite, Regeneration
  • M. Rahnamabaghy, A. Fallah Shojaei *, Z. Moradi Shoeili Pages 1366-1377
    CuMn2O4 NPs were prepared via coprecipitation method and characterized using microscopic and spectroscopic analyses. CuMn2O4 NPs exhibit a triple-enzymatic activity including peroxidase-, oxidase- and catalase-like activity. The effect of various parameters on the initial rate of the catalytic reaction of CuMn2O4 NPs with peroxidase- and oxidase-like activity was studied by UV-vis spectrometer following the increasing absorption at 415 nm corresponding to the oxidation product of substrate o-phenylenediamine (OPD). Kinetic analyses indicate the Michaelis-Menten model for CuMn2O4 NPs for both peroxidase- and oxidase-like activity. Based on the high peroxidase-like activity of CuMn2O4 NPs, they were further studied as a colorimetric sensor for the detection of H2O2 with a linear range from 0.5 mM to 22 mM and detection limit of 0.11 mM. Inhibition of the high oxidase-like activity of CuMn2O4 NPs was utilized for colorimetric detection of L-cysteine with a linear range from 50 µM to 200 µM and a detection limit of 54.15 µM.
    Keywords: Peroxidase, Oxidase, Catalase, CuMn2O4, H2O2, L-cysteine
  • H. Baniasadi, F. Rashidi * Pages 1378-1399
    In this study, by employing a novel analytical model for well test analysis, characterization is performed for a fractured-vuggy reservoir containing volatile oil with flowing wellbore pressure below the bubble-point pressure. Well test analysis in such medium is challenging due to complications in reservoir geology and fluid behavior. Rock complications arise because of existence of three media which interact with one another due to different flow behavior. Fluid related challenges are caused by gas liberation and two phase flow near the well bore. To perform the analysis, a synthetic model was investigated and pressure data were generated. Pressure data in such reservoir exhibited a radial composite behavior. Subsequently, a triple porosity radial composite model was developed for analysis and parameter estimations in such reservoirs. It is shown that reservoir parameters could be predicted with acceptable accuracy using the proposed model. The estimated effective permeabilities in all cases were close to the actual value, with absolute relative error less than 0.1. However the obtained interporosity flow parameters were slightly different from single phase parameters due to the presence of gas bank near the wellbore.
    Keywords: Two-phase well-test, Fractured-vuggy reservoir, Volatile oil, Radial composite model, Triple-porosity
  • S. Amirnejat, S. Javanshir * Pages 1400-1413
    Marine sulfated polysaccharide Irish moss (IM) coated BaFe12O19 nanocomposites were synthesized and characterized by Fourier Transform Infrared Spectrometer (FT-IR), scanning electron microscope (SEM (, X-ray diffraction (XRD (, vibrating-sample magnetometer (VSM (, and thermal gravimetric analysis (TGA). The indisputable privilege of BaFe12O19@ IM as a recyclable acid-base bifunctional catalyst has been studied in the preparation of benzopyranopyrimidines via a pseudo-four-component reaction of salicylic aldehydes, malononitrile, and various amines. Catalytic amount of BaFe12O19@IM shown high catalytic activity, and stability with negligible detriment in in its efficiency over five catalytic cycle. The catalytic property–catalytic performance associations clearly showed the synergistic effect between Irish moss, as major active phase, and barium ferrite nanoparticles enabling the catalyst separation in a magnetic field. Along with the catalytic activity, a study on the antibacterial performance of BaFe12O19@IM nanocomposites on bacteria strain was evaluated. The results showed that the prepared nanocomposites possess antibacterial activity against Gram-positive Staphylococcus aureus (S. aureus).
    Keywords: Marine sulfated polysaccharide, barium hexaferrite, magnetic nanoparticle, benzopyranopyrimidines, Heterogeneous catalyst, Green chemistry
  • N. Attaran *, H. Eshghi, M. Rahimizadeh, M. Bakavoli Pages 1414-1419
    Several new substituted 2,3-dihydro-1H-pyrrolizine-bridged bipyrroles were synthesized via ring annulation under green aqueous conditions. In this work, the acid-catalyzed condensation of the used diketones with pyrrole did not result in the formation of expected divergent bisdipyrromethanes. However, new important pyrrolizine-bridged bipyrroles were synthesized in good yields. Ferric hydrogensulfate was used as an environmentally friendly homogeneous acidic catalyst to produce pure products in aqueous conditions. This catalyst has enabled us to synthesize pyrrolizine-bridged bipyrroles with bearing functional groups at designated positions. These synthesized compounds can be used for various unknown and known applications such as chiral catalysts and essential biological activities.
    Keywords: pyrrolizine, bipyrroles, ferric hydrogensulfate, green condition
  • M. Nikfar, D. K. Kim *, K. Y. Choo, A. Alemrajabi Pages 1421-1427
    In the flow-electrode capacitive deionization (FCDI), the highly activated porous carbon electrodes of slurry phase flows through the channels of current collectors and adsorbs the salt ions when a voltage is applied. In this study, the effect of voltage on the performance of a FCDI cell is experimentally investigated. The voltage is applied on the top corner of a FCDI cell (Vapply) and simultaneously the voltage of central cell (Vcell) is measured. The experiments were conducted by applying voltages from 0.6 to 3.9 V. The experimental results show that the difference between Vapply and Vcell is a function of salt concentrations of the feed water. The higher voltages (Vapply>1.2V) can be used for increasing the salt removal efficiency (E) for higher salt water concentrations without electrolysis. Also, the results show that E increases along with the applied voltage. A series of pH measurements were done in regard to investigation of electrolysis point of the setup.
    Keywords: Voltage, Water desalination, Capacitive deionization, Flow electrode
  • E. Jooybar, T. Tajsoleiman, M. J. Abdekhodaei * Pages 1428-1435
    An exact solution for the release kinetic of a solute from inside a hollow cylindrical polymeric matrix into an infinite medium has been developed, when the initial concentration of the solute (A) is greater than the solubility limit (Cs). A combination of analytical and numerical methods was used to calculate the solute concentration profile and the release rate. The model was developed for two different strategies: 1) the release medium is flowing through the hollow cylinder in which boundary layer may be neglected, 2) the release medium inside the hollow cylinder is stagnant and the boundary layer should be considered. The results indicated that the release profiles were close to the constant release rate after a typical burst release. Also, the release profile from a solid cylindrical matrix and a hollow cylinder was compared. The results indicated that the hollow cylindrical matrix is a promising carrier when zero-order release is desirable. The present model demonstrates the potential of the hollow cylindrical matrix as a suitable geometry for sustained drug delivery systems.
    Keywords: Dispersed solute, Hollow cylinder, Controlled release, exact solution, Moving boundary
  • R. Abdollahi, V. Goodarzi, M. H. Baghersad * Pages 1436-1451
    Heavy metal ions have been recognized as the most hazardous contaminants of water sources. In this study, a novel polymeric adsorbent based on 2-hydroxyethyl methacrylate (HEMA), acrylic acid (AA), and 1,4-butanediol dimethacrylate (BDDMA) was successfully synthesized and its efficiency in removal of selected heavy metal ions (Pb2+ and Cd2+) were investigated. The role of significant parameters such as pH, contact time, adsorbent dose, metal ions concentration and temperature on removing harmful metal ions were logically studied. Results showed that the amount of pH, contact time and polymer adsorbent dose had direct relation in adsorption of metal ions. While increasing metal ion concentrations have no significant effect in metal ions adsorption and that was fixed up to 15 mg/L. Adsorption isothermal process of the new polymeric adsorbent was studied by several selected models and also maximum values of adsorption capacities of the introduced adsorbent for Pb2+ and Cd2+ ions were characterized. Adsorption /desorption cycles of synthesized polymer adsorbent were around 15 times. According to the modeling of adsorption data, the pseudo-second-order kinetic equation could best describe the adsorption kinetics. According to the intra-particle diffusion studies adsorption of heavy metal ions might be dominated by external diffusion mechanism.
    Keywords: Polymeric adsorbent, Heavy metal ions, Isotherm, kinetic, Thermodynamics
  • S. Asleshirin, H. Mazaheri *, M. R. Omidkhah Nasrin, A. Hassani Joshaghani Pages 1452-1463
    Ionic Liquid(IL)now refers to fluids that are liquid at temperatures above 100°C, they are called "Green"solvents.One of their applications is in heat transfer and solar collectors.Thermophysical properties can be improved by adding nanoparticles to the IL.For this reason,spherical and rod-shaped alumina nanoparticles were added to 1-Hexyl-3-methyl imidazolium hexafluorophosphate IL with different weight percentages. The effect of adding nanoparticles on thermophysical properties of IL such as density,viscosity,thermal conductivity, and heat capacity in 0.05,0.1 and 0.5 %wt of nanoparticles at temperatures of 20, 30, and 50 °C is investigated. Increasing the concentration of nanoparticle set out an increase in density, viscosity, and thermal conductivity and a decrease in the thermal capacity of the ionic nanofluid (INF) compared to the base IL.Also, the viscosity, density, and thermal conductivity in INF with rod-shaped alumina nanoparticles are improved more than spherical alumina nanoparticles. Also the experimental viscosity and thermal conductivity data were fitted with the existing theoretical models. the viscosity of spherical alumina-IL and rod-shape alumina-IL was in unison with particles aggregation effect (Krieger-Dougherty model) and the both INF effective thermal conductivity are prognosticated by interfacial layer approach with sufficient accuracy.Eventually nonlinear equations have also been proposed for changes in the thermophysical properties of viscosity.
    Keywords: Alumina Nanoparticles, Thermal Conductivity Coefficient, Density, Heat Capacity, Ionic Liquids
  • M. Hajiali, M. Farhadian *, S. Aflaki, N. Davari Pages 1464-1477
    This study aimed to remove one of the frequently used dyes in textile industries, Methyl Orange, from pollutant water with TiO2/ZnFe2O4/Glycine nanocatalyst under UV irradiation. The TiO2/Glycine/ZnFe2O4 nanocatalyst was synthesized through the sol-gel method and characterized by XRD, XRF, FT-IR, UV-Visible DRS, BET, FE-SEM, and EDX analyses. Process factors, including initial dye concentration (10-30 ppm), nanocatalyst dosage (0.5-1.5 g/L), initial pH solution (3-11), and irradiation time (30-150 min), were investigated by central composite design. The removal efficiency of Methyl Orange was 80% under optimal conditions (dye concentration: 20 ppm, nanocatalyst dosage: 1 g/L, irradiation time: 120 min, and pH=6.5). The effects of mineral salts such as NaHCO3, NaCl, Na2SO4, KCl, MgSO4, and CaCl2 with the concentrations of 50-800 ppm on the dye removal efficiency were examined under the optimal conditions. Low concentrations of NaCl, KCl, and CaCl2 had adverse effects on MO removal efficiency, while the dye removal efficiency raised at their high levels (RNaCl.800=74.52%). An increase in concentrations of MgSO4 and Na2SO4 led to deactivation effects on the dye removal efficiency and reaction rate constant (MgSO4 deactivation: 36%). There was an upward trend in the pollutant removal efficiency and reaction rate constant using NaHCO3 (RNaHCO3.800=82.4% and kNaHCO3.800=20.84 day-1).
    Keywords: Methyl orange, Photocatalysis, TiO2, ZnFe2O4, Glycine, Mineral salts, Reaction rate constant