Applied Chemistry Today
Year:2020 | Volume:15 | Issue:54|Papers Count:24

In this present study, preparation of graphene oxide is improved. Graphene oxide was obtained with high purity and high interlayer distance in low time via changes in Staudenmaier method. Then, graphene oxide was functionalized with Fe3O4 nano particles. Characterization was carried out by FT-IR and XRD techniques. Then, adsorption of Pb2+ and Pd2+ ions from aqueous solution was investigated using functionalized and no functionalized graphene oxide. Several important parameters in the adsorption were studied such as sorbent mass, contact time, pH, temperature and metallic pollutants amount. The maximum adsorption value of Pb2+ ion were 86. 5 and 93% using graphene oxide and magnetic graphene oxide, respectively. While, maximum adsorption value of Pd2+ ion were 63 and 78% using these adsorbents. The experimental results showed that lead and palladium ions adsorption much better fit with the Freundlich and Temkin isotherms. The best model for the adsorption kinetic was shown with the Logergren and Elovich kinetic models. It can be concluded that the magnetic graphene oxide has high adsorption, which can be used as an effective adsorbent for Pb2+ and Pd2+ ions.

For the first time, green synthesis of Dy2Ce2O7 nanostructures with use of olive leaf extract was performed. The obtained Dy2Ce2O7 nanostructures were characterized with use of methods comprising TEM, DRS, XRD and FESEM. The results of this study denoted that Dy2Ce2O7 nanoparticles with pure fluorite structure can be prepared using olive leaf extract by an easy and green way. For the first time, Dy2Ce2O7 nanostructures (prepared with olive leaf extract) were employed as an effective photocatalyst in the degradation of methyl violet pollutant in aqueous solution. Findings denoted that this photocatalyst with very good stability, under similar conditions, can destruct the methyl violet pollutant in aqueous solution during the repeated tests.

Tungsten oxide nanostructures have been synthesized by simple, one-step hydrothermal method using sodium tungstate as precursor material. Citric acid and sodium sulfate have been used as surfactant. structural, morphological, chemical bonding, and optical properties of products have been thoroughly investigated by using X-ray diffraction (XRD), Field emission scanning electron microscopy (FESEM), Fourier transform infrared spectroscopy (FTIR), and Diffuse reflectance spectroscopy (DRS), respectively. The obtained results indicated that the hydrothermal temperature is a key parameter which controls properties of the sample. Phase transition and shape evolution has been observed during temperature increment. Synthesized nanostructures showed wide bad gap and therefore have potential applications such as photochromic material.

To address the obstacles facing the clinical use of cisplatin (cis-diamminedichloroplatinum(II) (CDDP)), including poor bioavailability, severe dose-limiting side effects and rapid development of drug resistance, a novel pH-sensitive superparamagnetic drug delivery system was developed based on hyperbranched poly(ethylene glycol-b-citric acid) modified Fe3O4 nanoparticles (Fe3O4@PCA-b-PEG) for targeted delivery and pH-triggered intracellular release of cisplatin. The Fe3O4@PCA(CDDP)-b-PEG nanoparticles exhibit excellent water dispersity with well-defined size distribution (around 49. 5 nm) and strong magnetisability. In vitro release experiments revealed that the CDDP-loaded delivery system is relatively stable at physiologic conditions (pH 7. 4 and 37 ˚ C) but susceptible to acidic environments (pH 5. 3 and 37 ˚ C) which would trigger the release of loaded drugs. Fluorescent microscope studies revealed that the Fe3O4@PCA(CDDP)-b-PEG nanoparticles could be efficiently accumulate in tumor tissue. Also, in comparison with CDDP, the Fe3O4@PCA(CDDP)-b-PEG exert higher cytotoxicity towards the human cervical cancer HeLa cells and the Human breast cancer MDA-MB-231 cells. The results indicate that the prepared superparamagnetic Fe3O4@PCA(CDDP)-b-PEG nanoparticles are a promising candidate for inhibiting proliferation of cancer cells.

In this research work novel PVC-supported triazole-copper(I) iodide catalyst (PVC– Triazole– CuI) was prepared and used the for synthesis of 1, 2, 3-triazoles. The catalyst was prepared in two steps; First PVC-N3 obtained from the reaction of NaN3 with PVC in water, then reaction of this compound with propargyl alcohol and copper(I)iodide in ethanol led to PVC-Triazole-CuI as the catalyst. The structure of the catalyst was characterized via different analytical tools, such as FT-IR, elemental analysis, ICP and SEM. This catalytic system was successfully applied for the three-component synthesis of 1, 4-disubstituted 1, 2, 3-triazoles by the click reaction of terminal alkynes, sodium azide and organic halides. The advantages of this method are high reaction yield, short reaction time, and capability of recovering and reusing the catalyst. In addition, water, as a green medium, is used in the synthesis of 1, 2, 3-triazoles.

In this research, the adsorption capacity of the Ziziphora plant ash collected from the village of Kib, Jurm township of Badakhshan province of Afghanistan country were studied on the removal of methylene blue from aqueous solutions. At first, the adsorbent was prepared in its natural form and then turned into powder. The powder obtained by the furnace is turned into ash at 500 ° C. Natural adsorbent Ziziphora plant ash were characterized by Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM). In this study, investigated the effects of various factors such as pH, contact time, initial dye of concentration, dose of adsorbent, ionic strength and temperature. Then, the thermodynamic parameters of the adsorption process such as ∆ H^° , ∆ S^° and ∆ G^° were calculated. Thermodynamic investigations showed that the adsorption of methylene blue dye increased by increasing the temperature on the natural adsorbent of the Ziziphora plant ash and that indicating the adsorption process was endothermic. The kinetic adsorption conditions were investigated with first and second order kinetic models and the results showed that the methylene blue absorption process were followed to the second-order kinetics model. The isotherm of the adsorption process were studied using Langmuir, Freundlich, Tamkin and Dobbin-Radskvich models. The results of the experiments showed that the adsorption process followed by Langmuir model with a maximum adsorption capacity (59. 1 mg. g-1).

One of the common methods for the removal of acidic gases in the natural gas is the membrane technology. Poly ether block amide (PEBA) copolymer is one of the most important and talented membrane materials in this field which is applied in multilayer composite structures. In this study, PEBA polymeric layers have been fabricated on nanostructure polysulfone (PSF) supports using dip coating method without gutter layer in order to separation of CO2 from N2 and CH4. The AFM analyses have shown that pore size and mean roughness of PSF support are 10. 12 and 6. 87 nm, respectively. The morphology of fabricated membranes with solution concentration of 2 and 3wt% has been characterized by scanning electron microscope (SEM) and their performance has been investigated with pure gas permeations. The obtained results have shown that the composite membrane with selective layer of 3wt% PEBA had a suitable performance with permeance of 27 GPU for CO2 and ideal selectivity of 46 and 23 for CO2/N2 and CO2/CH4 separation, respectively. Moreover, the effect of pressure difference on membrane performance has been studied. The results have shown that the permeance and ideal selectivity of membrane increases with increasing of pressure difference.

In this paper, Fe3O4 modified with CuV2O6 was synthesized for the first time and its efficiency as a photocatalyst was evaluated. The new nanocomposite was characterized using UV-Vis spectrophotometry, X-ray diffraction, Fourier transform infrared spectroscopy and a field emission scanning electron microscope. Then, as a photocatalyst it was tested for methylene blue degradation in the presence of visible light. The results showed that Fe3O4 modified with CuV2O6 is more efficient than unmodified Fe3O4. Its high efficiency is due to the high absorption of visible light by the nanocomposite. Also, the conditions of the test, including the amount of photocatalyst, color concentration and pH of the solution were optimized. The synthesized photocatalyst can degrade methylene blue in the presence of visible light with high efficiency.

N-butyl-N-nitroxyethylnitramine (Butyl-NENA) is a nitramine-based softener that is widely used in the formulation of Nitramine compounds, such as HMX and RDX (gas generator components in the airbag, etc. ). In this study, a new preferred method has been developed for the synthesis of Butyl-NENA, which is safe and economiccompared to the reported synthesis routs. In this Project, the electrochemical synthesis of dinitrogenpentoxide was carried out in two processes of constant electric current and potential. Afterwards, Butyl-NENAwas synthesised using 2-butyl aminoethanol as a precursor, and subsequently a solution obtained from the electrolysis. During the synthesis of Butyl-NENA, time, temperature, and molar ratio of the reactants were optimized. The results of the sequential syntheses showed that the suitable temperature of nitration, the reaction time, and the molar ratio of Alcohol to Dinitrogenpentoxidesolution were 35 ° C, 1 hour, and 1: 3 respectively. In this way, temperature control is easily possible. The factors affecting the synthesis were investigated using Regression Test Design method. The results showed that the factors including temperature, molar ratio, and the reaction time do not act independently, and accordingly, the effects of their interactions were calculated.

In this study, the application of adsorption process in the treatment of wastewater containing styrene has been evaluated and for optimizing process conditions, the surface response method (RSM) has been used. In this method, the experiments were performed on the basis of the central combination design, based on the change in contact time, pH, initial concentration of styrene and the amount of adsorbent as an effective factor in removal of styrene. In the first section, the PANIL/Fe3O4 nanoparticle absorbent was used to detect adsorbent analyzes of VSM, EDX, FT-IR and SEM. Analysis of variance shows that the obtained relationship to remove styrene has the ability to match the experimental data to 0. 949. The best conditions for removal of styrene, contact time of 5 minutes, pH 6, initial concentration of styrene 40 ppm, and adsorbent content of 0. 08 g were obtained. First-order and quadratic kinetic models were investigated, which showed that the pseudo-second-order model (R2=0. 99) showed the highest correlation with experimental data. The absorption parameters of styrene were evaluated using three models of Tamkin, Langmuir and Freundlich absorption symmetry. Considering simultaneously the two correlation coefficients, the Tamkin model (R2=0. 99) showed the best fit to the absorption data.

In this study trimetallic Ni-Mo-W/alumina catalysts with different percentages of tungsten were synthesized by a hybrid method of ultrasound-precipitation. Synthesized catalysts were characterized by XRD, BET, FTIR, FESEM and EDX and then were evaluated in hydrodesulfurization of thiophene. Thiophene removal in trimetallic Ni-Mo-W/alumina catalysts reached to 89. 23% while was 66. 72% for bimetallic similar catalyst. Among different tungsten contents the highest thiophene removal and butane/butene ratio was attributed to the catalyst with 6% wt. tungsten. This catalyst showed small nano crystallites of metal oxides with uniform morphology with average size of 13 nm. The post characterization tests confirmed the stability in crystals of catalyst but some changes in morphology and functional groups were observed. Moreover the effect of residence time and thiophene concentration on the activity and selectivity of the trimetallic catalyst with 6% wt. tungsten was studied and the results showed with increasing the reaction time and reducing thiophene concentration, activity of the catalyst enhanced.

In this research, nano-silica coated with phosphotangestic acid was used as a new, effective and heterogeneous high-selectivity catalyst for the diastereoselective synthesis of trans-2, 3-dihydrofuran during, multi-component one-pot and solventless reaction. In this reaction, the in-situ production and condensation of pyridinium bromide ylide are carried out with benzaldehyde and 4-hydroxy-coumarin derivatives. The size and shape of the catalyst were studied using detection methods such as scanning electron microscopy (SEM), Transmission electron microscopy (TEM), X-ray diffraction spectroscopy (EDS), and Fourier-transform infrared spectroscopy (FT-IR). Also, the BET analysis of this nano-catalyst showed a high surface area, which could be a factor in the good performance of this nano-catalyst. An induction coupled plasma analysis also confirmed the ability to recover of this nanocatalist. The reaction products were evaluated using FT-IR spectroscopy and melting point determination. High efficiency, short reaction time, solventless conditions and easy product separation method are the future advantages of this research.

In this research, the magnetic nanoparticles coated with chitosan have been used to remove the reactive red 120 azo dye from aqueous solution. Chitosan is one of the most well-known biopolymers that can be used as adsorbent for the removal of color contaminants. Fe3O4 magnetic nanoparticles were synthesized by simultaneous combination of FeCl3. 6H2O and FeCl2. 4H2O, and coated by chitosan polymer with low molecular weight. Then magnetic nanoparticles coated with chitosan were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared radiation (FTIR), X-ray diffraction (XRD) and Vibrating Sample Magnetometer (VSM). Moreover, the effects of three parameters: pH, initial color pollutant concentration and adsorbent dosage on the adsorption were studied. The maximum adsorption about 98. 99 percent occurs at pH=4, 150 mg/l of the initial concentration of azo dye and adsorbent dosage of 6 g/l. Adsorption data were fitted with Langmuir and Freundlich isotherm models. The results showed that the adsorption data on magnetic chitosan nanocomposite is more adapted with Freundlich model.

A novel and effective method in order to improvement of synthesis of pyrazole-fused isocoumarins from available materials such as ninhydrin and arylhydrazones was consider in this paper. A variety of substituted pyrazole-fused isocoumarin were synthesized by a one-pot reaction of ninhydrin and arylhydrazone in ecxellent yields under solvent-free conditions. In this reactions γ-Fe2O3-SO3H was used as, reusable, green and efficient catalyst. The attractive advantages of this method are the high yields, mild condition and reusability of the catalyst. The pyrazole-fused isocoumarin derivatives have a wide range of biological activities such as antimicrobial, antimalarial, and some of them are known as GABA receptor.

Due to the destructive effects of heavy metal ions on human health, providing a simple and inexpensive way to detect and measure them in an aquatic environment is one of the important research areas. In the present work, a simple optical sensor based on gold nanoparticles with chitosan was introduced to detect and measure heavy metal ions in water. These metal ions result in the accumulation of gold-chitosan nanoparticles through the chelating reaction between chitosans and metal ions. The sensitivity of the sensor was investigated for Cu2+, Ni2+, Pb2+, Cd2+ and Hg2+ ions. The results showed that different metal ions cause a different reduction in the plasmon bar. The detection limit for each copper, nickel, lead, cobalt, cadmium and mercury ions was 2. 48, 0. 27, 0. 25, 0. 40, 0. 28 and 1. 43, respectively. This optical sensor showed the most sensitivity to Pb2+ ions. According to the results, this sensor can successfully be used to detect heavy metal ions in water and wastewater samples.

Micro-pyramidal structures have been synthesized on the single crystalline silicon (Si) substrate, using anisotropic etching in the potassium hydroxide (KOH) solution in the presence of the isopropyl alcohol (IPA) as the additive. Effect of the different parameters such as the concentrations of KOH and IPA and temperature on the etching process has been studied. Extracted results show that higher concentrations of the KOH and IPA, as well as the increasing temperature, lead to the larger pyramidal structures and less uniformity in their size and distributions. Incorporation of the porosity to the Si surface, before etching in the KOH solution can enhance the uniformity of the formed pyramidal structures. To the best of our knowledge, in this paper for the first time, we survey effects of the porosity which is created by the metal assisted chemical etching (MACE) method, on the formation of the micro-pyramids. Performing thermal treatment on the produced silver mask during MACE process before etching process, improves uniformity of the synthesized pyramids. For studying morphology of the formed structures, we use the field-emission scanning electron microscope (FE-SEM) images. Moreover hydrophilic behavior of the pyramidal structures has been studied. Contact angle test results show that more uniformity in the size and distribution of the structures, enhances the hydrophilicity of the surface.

In this research functionalized pyridines are produced from the reaction of propiolates, N, N′-di-tert-butylcarbodiimide, -bromo ketone and triphenylphosphin in the presence of catalytic amount of Fe3O4-MNPs at 70 oC in water as green solvent. In this research the Fe3O4-MNPs is prepared from water essential oil extracted of orange peel. The good yield of product, short reaction time, easy separation of catalyst, performing the reaction in water as green solvent, easy separation of product by filtration and green synthesis of catalyst are advantages of this method in synthesis of pyridine derivatives. It should be mentioned, these reactions have very low yields without any catalyst. Also, in this research the antioxidant activity of some new synthesized pyridines such as 5b, 5c, 5d and 5e were investigated by DPPH radical trapping and reducing potential testes of ferric ion. The results were compared with the synthetic antioxidants (TBHQ and BHT).

Solid polymer electrolytes (SPEs) show good structural fl exibility and safety to meet the requirements of lithium-ion battery applications. Poly(vinylidene fluoride) (PVDF) is a semi-crystalline polymer which due to its desirable has been considered as promising candidate for fabrication of polymer electrolytes in Li-ion batteries. PEs usually have a low ionic conductivity at room temperature. In this study, in order to eliminate this problem and improve the ionic conductivity improving additives of lithium-ion battery graphene oxide (GO) were investigated. Then, the additive amount was optimized using the Morphology, Tensile strength, ionic conductivity, Li+ ion transference number and electrochemical stability, which determined the optimal amount of (GO). SEM images were shown that SPEs containing GO have more porosity in comparison with GPE without GO. By adding 0. 004 wt% GO, the ionic conductivity of the PVDF/GO polymer electrolyte was increased significantly to 3. 60 mS cm-1 for the composite and the transference number of Li+ ion was also increased to 0. 74. The electrochemical stability of 4. 6 V was achieved. The results show that GO not only increased the ionic conductivity of composite membrane but also improved the physical properties of the polymer electrolyte. This study shows that the PVDF/GO polymer electrolyte can be considered as a promising SPE for lithium ion batteries.

The MX%-CeO2 (M=Zr4+, V3+) nanorods were synthesized via hydrothermal method. The field emission scanning electron microscopy (FESEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD) were used to investigate the surface morphology and know the structural properties of the nanorods. The nanorods were used to make sensors and their sensitivity be tested for volatile organic compounds including methanol, acetone, ethanol and 2-propanol. The results showed that Zr4+ and V3+ dopant ions play a vital role in the structure and the size of rods. According to the sensing results these nanorods exhibited stronger and faster response to ethanol gas than the bare CeO2. While the CeO2 nanorods showed the sensitivity of 4. 5 units for 340ppm ethanol concentration, sensitivity of doped samples with V3+ and Zr4+ ions increased to 10. 32 and 5. 66 units, respectively. The sensitivity enhancement described by the larger modulation of the conduction channel width and interfacial potential barrier height. According to the results, Zr20%-CeO2 and V1%-CeO2 sensors were more sensitive and selective to ethanol, compared to the other samples.

Prediction of drugs solubility in various solvents is one of the main challenges in drug discovery and advanced investigation. The thermodynamic models are fast, reliable, and cost-effective methods to select the best solvent or solvent mixtures to increase drug solubility. Experimental solubility determination is not always possible because of the small amount of product available in the early stages of a drug development. In this paper, UNIFAC activity coefficient model is tested for prediction of naproxen (NAP) solubility in two choline-based DESs and the performance of this model is compared with experimental data. The average relative deviation of this model for investigated systems is 10. 57% and 15. 27% showing that experimental measurements are carried out with high exactitude.

The aim of this study was to synthesize Cu and S co-doped TiO2/SiO2 nanoparticles as novel photo-catalysts under the visible light via sol-gel method. The structural properties of the nanoparticles characterized by XRD, DRS-UV/Vis, FE-SEM, TEM and EDX analyses. The results obtained from XRD showed that both the pure and the modified TiO2 nanoparticles comprised only the Anatase phase. The photocatalytic effect of synthesized nanoparticles in the degradation of congo red (as a model of dye polluted wastewaters), was studied. The operational parameters include the irradiation time, pH, the photocatalyst dosage and the pollutant concentration optimized by the response surface methodology (RSM) using the central composite design (CCD). The findings suggested that the optimized conditions for the irradiation time, pH, photocatalyst dosage and the pollutant concentration were 115. 98 min, 4. 52, 0. 08 g and 13. 51 ppm, respectively. The photocatalyst degradation under the optimized conditions reached to the 99. 8%. Furthermore, the results confirmed that adding thiourea as the sulphur source and copper nitride as the copper source increased the photocatalytic activity in the visible light range. In addition, the UV-Vis spectrophotometry results showed that the synthesized nanoparticles were efficient under the purple irradiation. Finally, coupling the electricity with the photocatalytic process proved that the electrical current was considerably efficient in decreasing the degradation time of removing the congo red dye from aqueous solutions at the high concentrations.

In the peresent work, new aluminium complex from a Schiff base ligand was synthesized and characterized. The Schiff base ligand was derived from the condensation of 5-bromo-2-hydroxybenzaldehyde with 8-aminoquinoline. The synthesized compounds were characterized by elemental analyses, FTIR, and UV-Vis spectroscopy. Alumina nanomaterials were synthesized via thermal decomposition technique using aluminum Schiff base complex. The properties of the obtained nano alumina was studied by FTIR spectra. To investigate the phase formation, powder X-ray diffraction technique was used. Rietveld refinement using powder XRD confirms structure model determined by X-ray diffraction. SEM micrographs were used to investigate the morphology of the obtained material. Anticancer activity of these compounds on MKN-45 and LS174T cancer cell-lines was investigated by MTT assay. All compounds showed anticancer activity and have a very good inhibitory effect on the growth of cells. The cell viability decreased with the increasing concentrations of all compounds. Based on the results, it was found that the proliferation rate of cancer cells decreased after treatment with the compounds in a dose dependent way.

In this work, electro-conductive polymers including polyaniline and polyindole were used to protect the carbon steel corrosion (carbon steel with the API5LX52 grade). Electropolymerization of composites containing polyaniline and polyindole on carbon steel was performed in an aqueous solution containing oxalic acid by using cyclic voltammetry (CV) method. In this work, water as a solvent was used due to reducing costs and environmentally friendly issue. Using electrochemical impedance spectroscopy (EIS), it was found that the composite coating provides better protection than polyaniline and polyindole against corrosive materials (in this work, 3. 5% NaCl) for carbon steel. FTIR method was used to identify synthesized samples. FTIR peaks of synthesized polyaniline and polyindole are matched with their respective FTIR index peaks at the references. The resulting index peaks in FTIR of composite coating indicate that the coating contains polyaniline and polyindole.

The application of photo-catalysis technologies using nanomaterials based TiO2 increased as an applied strategy in different industries in the recent years. In this regards and in the presence study, Fe3O4/Al2O3/TiO2 nanostructure with core/shell/shell shape was synthesized and characterized by FT-IR and SEM methods. After confirming of synthesized procedure for magnetic TiO2 nanomaterial, it used for photo-catalysis degradation of methyl orange dye under Uv light. The effective parameters in removal yield for optimization of photo-catalysis systems was investigated. Results showed 100% removal yield for methyl orange under condition of 3. 3 gr/lit photo-catalyst at pH=7. 0 and the presence of 30 ppm at 60 min was occurred. In addition and for nano-catalyst without between layer 44% yield was occurred. In conclusion, Fe3O4/Al2O3/TiO2 nanostructure showed better photo-catalysis behavior compare to Fe3O4/TiO2 nanostructure.