JOURNAL OF APPLIED CHEMISTRY
Year:2013 | Volume:8 | Issue:26|Papers Count:9

Graphene with unique physico-chemical properties is known as a new phenomenon in material science. Combining the properties of graphene with other nanomaterials , results in exceptional nanocomposites. One route is the decoration of graphene sheets with nanocrystals. On the other hand application of zero valent metals for the wastewater treatment is a widely accepted technology. In this study the nanocopper decorated graphene composite was synthesized and characterized using different methods. The possibility of its application in the degradation of 4-(2-pyridylazo) resorcinol dye was investigated. The results showed that under optimal conditions , degradation of 50 ml dye solution (100 mg L-1) with 2 g L-1 of nanocomposite is achievable.

This article, describes a new method for synthesis of diazo dyes. In this protocol, cellulose sulfuric acid has been used as a proton source for producing diazonium salts. The resulting anion, in the presence of diazonium salt (ArN2+-O3SO-Cellulose), causes high stability of this salt at room temperature, and also results avoidance the use of harmful acids. This procedure for the preparation of diazonium salt was carried out under solvent free condition. The mixtur of amine, sodium nitrite and cellulose sulfuric acid, was grinded in a mortar and by grinding futher, coupling reaction was carried out. So by using cellulose sulfuric acid, diazo dyes with different derivatives were prepared in good to excellent yields and short reaction time, in one pot under ambient condition.

In this paper, the first part the chemical co-precipitation method was used in the preparation of magnetic nanoparticles and then application of SDS-coated Fe3O4 NPs as an adsorbent for extraction of trace amounts of terbinafine hydrochloride from pharmaceutical company wastewater was investigated. Then the drug was determined by high performance liquid chromatography with UV detection (HPLC/UV). The effects of various parameters on the extraction efficiency such as pH of solution, amount of SDS surfactant, extraction time, eluent type and desorption condithions were studied and optimized. Under the optimal conditions, the calibration curve was linear in the range of 1.0-400 mgL-1 with a correlation coefficient of 0.9998. Enrichment factor of 74 and limit of detection of 0.5mgL-1 were obtained. Also, the percent relative intra-day and inter-day standard deviation (R.S.D %) based on three replicate determinations were 1.0 and 3.5%, respectively. According to the results, the proposed method was successfully applied to extraction of terbinafine from environmental samples and satisfactory results were obtained.

In this study, eucalyptus leaves ash (ELA) was used as a low cost adsorbent for simultaneous removal of Cd(II), Ni(II) and Co(II) ions from aqueous solutions. The adsorption parameters, such as initial pH of the solution, contact time, adsorbent dose and temperature, were studied and optimized. Evaluation of the obtained data with isotherm studies indicated that the adsorption process was matched well with the Langmuir model. The maximum capacity of adsorbent for Cd(II), Co(II) and Ni(II) ions were 166.7, 27.03 and 23.8 mg g-1, respectively. Kinetic studies were carried out on various kinetic models and the pseudo-second order kinetic model was fitted very well with experimental data. Moreover, base on thermodynamic studies the adsorption process was both endothermic and spontaneous.

In this investigation, IR spectroscopy, HOMO-LUMO analysis, NBO analysis, polarity determination, bond length, bond angle, natural charge of atoms, hardness, Softness, electrophilicity index and chemical potential from H2O to H2Te are calculated. DFT (Density Functional Theory) calculations with methods (PBEPBE and HCTH) and DGDZVP basis set were performed. According to the calculations, polarizability increases from H2O to H2Te and the HOMO-LUMO energy gap decreases. Using IR spectroscopy, vibrational active modes of the compounds have been studied. The vibrational frequencies decreases from H2O to H2Te due to the increase in bond length.

Gasoline with euro 5 standard and improvement of selectivity of isomer products to aaromatic products in gasoline is very important in oil refinery.In this paper, Pt-Re-Sng Al2O3 catalyst prepared with imperegnation procedur. Then, The activity and catalytic reactor tests for prepared catalysts and commercial catalyst with same of commercial catalytic reforming process conditions and industrial feed in differential plug flow reactor of catalysis and nano technology division, research institute of petroleum industry pilot plant were done. The composition of Pt and Re in catalyst prepared was 0.22 and 0.44 and range of Sn composition was 0.06, 0.1, 0.2 and 0.3 weight percent. After activity test and analysis of products, selectivity of isoparaffins products to aromatics products was compared. The results show that the selectivity of isoparaffin to aromatic products at two different temperatures (490-510oC) for prepared catalyst with 0.3 weight percent of tin and commercial catalyst were 39.5, 29.7, 4.4 and 13.2, Respectively. Finally, comparison of selectivity of four prepared catalysts and commercial catalyst in two operation conditions show that prepared catalyst with 0.3 weight percent of tin at 490oC is suitable for new catalytic reforming process.

Naturally fractured carbonate reservoirs have very low oil recovery efficiency owing to their wettability and tightness of matrix. Recovery efficiency can be considerably improved by changing reservoir rock wettability from oil-wetting to water-wetting state. In this work, the effect of different ions, pH, and temperature on wettability of carbonate rocks was investigated by means of contact angle measurements. The results indicate that the Ca2+, Mg2+ and SO42- ions can change the wetting state of carbonate rocks toward water-wetting, both individually and when they are mixed. According to our measured contact angle data, simultaneous increase of the concentration of both Mg2+ and SO42- ions has positive impact on wettability alteration of the carbonate surface more than that of obtained by variation of individual ions. It is also found that addition of NaCl salt changes the wettability to more oil-wetting. We did, moreover, measure the impact of temperature on the wettability change of the carbonate surface. It is observed that higher temperatures result in water-wet surfaces, owing to facilitating fatty acid desorption. However, the impact of pH on wettability alteration is found to be complex, resulting in various wettability states by changing pH from 3 to 10.

Undoped and Ag-doped ZnO nanoparticles with different percentage of Ag (2%, 4%, and6%) were synthesized by a sol-gel method using a gelatin media as a polymerization agent. Zinc nitrate and silver nitrate were used as raw materials for reaction. The obtained nanoparticles were characterized by TEM, XRD, UV-vis, and PL. The TEM results showed that, the sizes of the nanoparticles were the same approximately. The XRD patterns indicated hexagonal structure for all samples and incorporation silver ions in to the ZnO lattice. The UV-vis and PL results revealed that, the optical properties of the undoped ZnO nanoparticles were better than the Ag-doped ZnO nanoparticles.

In this approach, functionalized carbon nanoparticles have been applied as modifier for determination of phenylephrine. The significant increase in voltammetric responses for pre-adsorbed phenylephrine compare with those for solution confirms high affinity of phenylephrine to carbon nanoparticles (possibly due to  p-p stacking interaction between aromatic rings of phenylephrine and surface-sulfonated carbon nanoparticles). To obtain the optimum of adsorption conditions, the effects of pH, agitation rate, and adsorption time are investigated. Differential pulse voltammetry was applied for quantitative determination of phenylephrine. The dynamic linear range 8.0´10-6 -8.0´10-5 mol L-1 and the limit of detection 9.5´10-7 mol L-1 was obtained. Determination of phenylephrine in biological sample was performed successfully.