Journal of Applied Research in Chemistry
Year:2017 | Volume:11 | Issue:2 |Papers Count:10

During recent years, the semiconductor photocatalytic process to remove persistent organic compounds in water attracts much attention because of its potential as a low-cost and environmental friendly treatment technology. In this research with the aim of obtaining optimum value of CuS and CdS content in CuS-CdS/TiO2 nanophotocatlysts, four samples varying in CuS and CdS contents were synthesized by hydrothermal method. The as-synthesized samples were characterized by XRD, FESEM, EDX, BET, and FTIR analysis. XRD results confirmed formation of CuS and CdS phases on TiO2 surface. According to the other characterization results the sample with 5:5:90 weight ratio of CuS:CdS:TiO2 owing to its high surface area, high relative crystallinity, and more uniform morphology can be optimum ratio to active phase loading in this photocatalyst. The photocatalytic activities of as-prepared samples were investigated based on the decolorization of Acid Orange 7 as model compound in an aqueous medium under visible light irradiation. The degradation efficiency was found to be 85.2, 100, 100 and 97.5% for TiO2, CuS(3)CdS(7)/TiO2, CuS(5)CdS(5)/TiO2 and CuS(7)CdS(3)/TiO2 nanophotocatlysts, respectively at reaction time of 100 min. According to the efficiency test results the sample with 5:5:90 weight ratio of CuS:CdS:TiO2 in shorter times (40 min) in comparison to other samples reaches to complete decolorization which was expected from characterization results too. The effect of initial dye concentration and photocatalyst dosage on degradation efficiency of optimum sample was evaluated.

Preparation of biodegradable and renewable material is a challenging issue when dealing with their industrial applications. Nanoporous clay were successfully prepared by acid modification of a natural clay. The catalyst was characterized by Fourier transform infrared (FT-IR) spectroscopy, X-ray powder diffraction (XRD), N2-sorption analysis, and transmission electron microscopy (TEM). The nanoporous clay was found to be efficient, recyclable, and durable heterogeneous catalyst for the Friedel-Crafts acylation of aromatic compounds with acid chloride and acid anhydride derivatives. This protocol provides a wide range of activated substrate applicability and avoids the use of heavy metal and co-catalyst. The catalyst can be successfully recycled and reused in 5 reaction runes. This reveals the excellent stability of the catalyst.

In this study, copper (I) oxide (Cu2O) nanoparticles was synthesized using copper acetate as precursor via supersaturation method. In order to increase the photocatalytic properties of Cu2O nanoparticles, Au was loaded on Cu2O by wet impregnation method and was characterized using XRD/ SEM/ EDXA techniques. Photocatalytic degradation of azo dye Direct Red 264 by Cu2O and Au loaded Cu2O nanoparticles under visible light was investigated. Efficiency of photocatalytic degradation by above catalysts was obtained 63.71 and 96.18%, respectively. Isothermic studies of photocatalytic degradation by these photocatalysts were examined. The Fritz-Schlunder 4-parameter and Badu isotherms were selected as the best models, with correlation coefficients 0.9960 and 0.9988 and with lowest error for Cu2O and Au loaded Cu2O nanoparticles, respectively.

In this research, lead sulfide (PbS) superstructures via a solvothermal process with using single - source precursor of lead hydroxythiocyanate (Pb(OH)SCN) were prepared. Superstructures of lead sulfide in different solvents such as oleic acid (OA) and N, N-dimethyl formamide (DMF) were prepared and the influence of morphology on the optical properties were investigated. The products were characterized by X-ray diffraction (XRD), morphology observations were performed on a field emission scanning electron microscopy (FE-SEM), and the light absorption and reflection properties were investigated by UV–Vis diffuse reflectance spectrophotometer. The investigation of their optical properties in the ultra violet and visible regions showed that the prepared PbS in DMF solvent compared with OA, had less reflectance and the absorbance (αs) for them were 0.955 and 0.918, respectively. The high solar absorptance and low emittance of these materials indicate that they are suitable for using in solar absorber coatings.

The plasma-assistance dry reforming of methane products (hydrogen and carbon monoxide) predicted at atmospheric pressure were simulated using artificial neural network. The experimental data required for modeling artificial neural networks was collected in a corona discharge plasma reactor. Effect of process parameters (plasma discharge power and feed flow rate) on the performance of the reaction, for example, methane conversion, and selectivity of the products were studied. A network with feed forward back-propagation algorithm, and Levenberg- Marquardt training function, tangant sigmoid activation function and linear activation function for hidden and output layer, respectivitly were used in this project. For example, artificial neural network model predicted methane conversion 25.12%, selectivity of hydrogen and carbon monoxide 71.15%, 74.85% in 4 w plasma discharge power. The model error values for the conversion of methane, hydrogen and carbon monoxide selectivity were 0.47%, 1.2% and 0.2%, respectively. A combination of genetic algorithms and artificial neural network to achieve optimum operating conditions were used in the reforming process. The results showed that the optimal feed flow rate and plasma discharge power were 175 ml.min-1and 6 watt, respectively. Also, the conversion of methane and hydrogen selectivity were 25.85% and 65.15%, respectively. The very small differences between predicted and experimental values confirm that combined neural network with genetic algorithm model is suitable tools for modeling and optimization of plasma-assistance methane dry reforming process.

In the this study, a volume-translated version of the Peng-Robinson equation of state (VTPR EoS) is developed for solid-supercritical fluids binary mixtures to estimate solubilities of solid component within a wide range of compositions and pressures. The solid investigated consisted of 2, 3-dimethylnaphthalen, 2, 6-dimethylnaphthalen, anthracene, indole, cinnamic acid, triphenylene, chrysene, cholesterol, phenanthrene and naphthalene, and the supercritical fluids consisted of carbon dioxide, ethylene, and ethane. Simulation results showed that the VTPR EoS had a better agreement with experimental data than conventional PR EoS. Minimum value of the percentage average absolute deviation (AAPD) was for VTPR EoS and anthracene-ethane system 3.72% and maximum value of AAPD was for PR EoS and cholesterol-carbon dioxide system 20.44%.

In this study, silver-vanadium oxide nanoparticles were prepared by a sol-gel method as an anti-bacterial compound. Vanadium pentoxide as a source of vanadium, and silver nitrate as a source of silver were used. The prepared nanoparticles were characterized by X-ray diffraction (XRD) method and scanning electron microscope (SEM) equipped with a system for elemental analysis (EDX). The obtained results confirmed the successful synthesis of the sample and monoclinic structure. Antibacterial tests were performed on Escherichia coli as a gram-negative bacteria and Staphylococcus aureus as a gram-positive bacterium by using disc diffusion and minimum inhibitory concentration methods. The results showed that antibacterial property of this compound was very good.

A new antitumor complex, “2, 2'-bipyridinehexylglycinatopalladium (II) nitrate”, has been synthesized by reaction between diaqu-2, 2'-bipyridinepalladium (II) nitrate and sodium salt of hexylglycinate. This complex has been characterized by conductivity measurement, elemental analysis and spectroscopic methods like FT-IR, 1H-NMR and UV-Vis. Interaction of this complex with Bovine Serum Albumin (BSA) at pH=7 has been carried out using UV-Vis spectrophotometry at 310 and 320 K and microcalorimetry at 320 K. This complex can denature the protein with positive cooperatively in binding (interaction of a molecule with BSA facilitate the interaction of second molecule) and its concentration in the midpoint of transition from native to denature, L1.2, 0.3 and 0.26 mM at 310 and 320 K, is quite low. In these studies, binding parameters: g (number of binding sites per BSA molecul equals 18), Kapp (apparent binding constant) 31.5 and 28.9 (mmol/L)-1, n (Hill coefficient, showing cooperativity of the system) are 1.2 and 1.3, and m (a measure of the metal complex strength for BSA denaturation) are 60.24 and 68.32 kJ/mol were found at 310 and 320 K, respectively. Thermodynamic parameters: DGo(H2O)0 (conformational stability of BSA in absence of metal complex) -21.247 (at 310 K) and -26.787 (at 320 K) kJ/mol and DHo(H2O)0 kJ/mol (enthalpy of BSA denaturation by the metal complex between 310 and 320 K) have been determined -174.315.