Journal of Applied Chemical Research
Volume:10 Issue: 4, Autumn 2016

Titanium diboride is one of the candidate materials for high temperature applications and also for control rod elements in high temperature reactors. This paper presents the experimental data on the composites of B4C-nano TiB2 that were synthesized successfully by co-precipitation methodat 1523K. Titanium tetraisopropanol, boron carbide, isopropanol and triton x-100were used as the precursor materials. Titanium tetraisopropanol and boron carbide were dissolved in isopropanol (solution A). Then, boron carbide was dissolved in deionized water and isopropanol (solution B). Solution B was gradually added to solution A. The prepared mixture was stirred and heated at 298K for 4h. In this research, B4C-nano TiB2 composites are contained 10 w% TiB2.The phase constitution and microstructure of B Cnano TiB2 during synthesis were investigated. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to determine phase and microstructure of TiB2-B4C composites. The distribution sizes of TiB2 nanoparticles on B4C were calculated between 10-82 and 20-35 nm without and with surfactant, respectively.

The influence of the number of operating parameters on photocatalytic and sonocatalytic Acid Red 88 degradation from an aqueous solution was investigated in this paper. The experimental results indicated that the sonocatalytic process with Ni-TiO2 was far more effective for the degradation of high concentration azo dyes, regardless of the process condition. In order to achieve a larger surface area of the catalyst, Ni-TiO2 was suspended in the aqueous solution. The optimum experimental conditions obtained as catalyst dosage of 0.6mg L-1, pH of 7 and dye concentration of 30 mg L-1. The COD value of the solution after photodegradation showed a significant decrease to 59 mg L-1 from 1573 mg L-1 while this value decreased to 34 mg L-1 after sonocatalytic degradation. The catalyst performance was evaluated by SEM and XRD techniques. Dye removal efficiency of 88% was obtained by sonocatalysis process with a dye concentration of 300 mg L-1 and within a pH range of 2-11. However, the efficiency was only 28% after photocatalytic degradation with the same dye concentration and within a more limited pH range of 3-9. Therefore, a specific method was proposed in this article for azo dye degradation.

Convenient and simple procedures for the synthesis of functionalized Quinoxaline derivatives were developed via one-pot four-component reaction of o-aminoanilin, acetylenic ester, and malonyl dichloride in the presence of K2CO3 as effective base catalyst. These compounds widely are used in various industries like paint, pharmaceutical and medicine. Quinoxaline derivatives are also part of antibiotics structure such as Actinomycin, Lomacin. In other hand, using of K2CO3 as economically catalyst and the simplicity of the present procedure for synthesis of Quinoxaline derivatives makes it an interesting alternative to complexmultistep approaches.. The structures of the newly synthesized compounds were confirmed by their elemental analysis and spectral data.

A green and convenient protocol is described for the preparation of E-1-(alkylamino)-3- (1,3-dioxoisoindolin-2-yl)-2-methyl-1-oxopropan-2-yl viaone-pot three-component reaction between 2-(2-oxopropyl)isoindoline-1,3-dione, an alkyl isocyanide and an E-cinnamic acid in water at room temperature. The methods used to follow the reactions are TLC and NMR, which indicated that there is no side product and the products were obtained without any purification. The structures of the products were deduced from their 1H NMR, 13C NMR and IR spectra. The present methodology offers several advantages such as a simple procedure, catalyst-free, mild reaction conditions, high yields, and the absence of any volatile and hazardous organic solvents.

We represent an environmentally friendly sample of pre-treatment method, ultrasound assisted emulsification microextraction (USAEME) followed by gas chromatography nitrogen phosphorous detector (GC-NPD), to specify atrazine residues in environmental samples. Some parameters affecting the extraction efficiency such as the type and volume of the extraction solvent, emulsification time and addition of salt are optimized. According to the results, 30 μL of chlorobenzene was chosen as the extraction solvent and the required time for quantitative analysis was 5 minutes without ionic strength and pH adjustment. Under the optimum conditions, limit of detection (LOD) is 0.02 μgL-1 and the percentage of mean extraction efficiency for 3 μgL-1 of analyte is 93.3% with good precision about 2.5% for triplet analysis. The calibration curve is linear at the range of 0.1-600 μgL-1. The procedure is applied successfully for assessing a matrix effect on agricultural water samples and lettuce with relative recovery of 100.8-102.5% with precision in the range of 2.5-3.2%. The results have demonstrated a successful robustness of the method for rapid and quantitative determination of trace amounts of atrazine in environmental samples.

A study of the [C6H6Ir(PH3)3] iridatropylium cation structure based on frontier orbital analysis, thermodynamic analysis, and natural bond orbital (NBO) theory is the main aim of the present research. Also, HOMO, LUMO energies, hardness, electrophilicity and chemical potential were calculated. Structural analysis indicated the optimized geometry shows a good agreement with the experimental results in iridabenzene.The thermodynamic properties at different temperatures were calculated, revealing the correlations between standard heat capacity, standard entropy, standard enthalpy changes and temperature. Quantum theory of atoms in molecule analysis (QTAIM) was used for characterizing of Ir-P and Ir-c bonds.

In current study,a hydrogel based on biocompatible polymerwas prepared. The functionalization of polyvinyl alcohol (PVA)with epichlorohydrin(ECH) to produce epichlorohydrin-g-polyvinyl alcohol (PVA/ECH) as a suitable macroinitiator for atom transfer radical polymerization (ATRP) reaction was investigated.ThenN-vinyl pyrrolidone (NVP) waspolymerized on the surface of macroinitiatorin presence of CuCl as a catalyst and Pentamethyldiethylenetriamine (PMDETA) as aligand using ATRP to produce PNVP-g PVA. The synthesized copolymer was characterized by Fourier transform infrared spectroscopy (FT-IR) and differential scanning calorimetry (DSC). Also equilibrium swelling was studied in distilled water and indicated the sustained expansion of them. At last, loading capacity and release profiles of ceftriaxone as a model drug from the hydrogel were determined by UV– Vis absorption measurement at λmax= 243 nm. In vitro drug release behavior was investigated in three different media (HCl solution: pH=3 and bicarbonate buffer solutions: pH=7 and pH=8).

An efficient and environmentally benign procedure for synthesis of triarylmethanes is developed via condensation of aromatic aldehydes and N,N-dimethylaniline using small quantity of heteropolyphosphotungstic acid (HPW) as catalyst in water. Good functional group tolerance, simple green experimental procedure, and good to excellent yields of products are the most advantages of this work.

In this paper, a new simple and effective method based on dispersive liquid–liquid microextraction procedure is proposed for rapid and simultaneous separation and preconcentration of ultra trace amounts of benzene, toluene, ethyl benzene and xylenes (BTEX) in non-alcoholic Beer samples. In this experiment, a glass syringe was used as extraction unit. With this simple configuration, the centrifugation step, which is a time consuming step was eliminated and also the possibility of using solvents with density lighter than water as extractant solvent was provided; and therefore applicability of DLLME will be expanded to a wider range of solvents. The influence of extraction parameters, such as kind and volume of extractant and disperser solvents, volume of sample and pH of the sample solution and its ionic strength were investigated and optimized. The best efficiency of extraction acquired using acetone and nonanol as dispersive and extraction solvents respectively. Under the optimum condition, the proposed method provided a linear range (10-1300 μg.L−1) with correlation coefficient ( 2) of 0.998, and relative recovery of 97.3-101.5%. The limit of detection was in the range of 2.0- 2.8 μg.L−1. At the end, the proposed micro extraction method was successfully applied for the determination of BTEX compounds in a few real non-alcoholic Beer samples.

In this study, Malvasylvestris flower extract (MFE) was used as a corrosion inhibitor for carbon steel in 1 M HCl solution. Malvasylvestris extract was analyzed by gas chromatography coupled with a mass spectrometry detector (GC-MS). Potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) studies revealed that the inhibition efficiency increases with increasing MFE concentration. Scanning electron microscopy (SEM) studies performed at various contact times of alloy with acid solution showed that the corrosion rate is reduced considerably in the presence of bioinhibitor. Corrosion studies at various temperatures (298 –338 K) showed that even at temperatures higher than 298 K the inhibition efficiency is good (>91%).Thermodynamic test results indicate that the MFE adsorption on the metal surface occurs by a chemisorption mechanism, and its adsorption isotherm is Langmuir.

Ferric ion is a strength oxidant and its precipitation is an undesired phenomenon in the bioleaching process. Previous studies showed that it considerably occurs in bioleaching operations even at optimum conditions. Although there have been many reports on the Fe3 precipitation, no study has made a mathematical modeling of the affecting parameters. The aim of the present work is the development of a model that represents the impact of some parameters on the Fe3 precipitation.The polynomial model was developed. The resulted model presents the positive effect of all parameters on minimization of Fe3 precipitation; particularly, the effects of pH and iron concentration, which are more significant. The validation of model was confirmed using F-test(P temperature> pulp density.

NanoTiO2, nanoZrO2 and TiO2/ZrO2 nanocomposite were prepared via sol gel method by using ultrasonic irradiation. The precursor sol of zirconium was prepared from an aqueous solution of ZrCl4 and titanium tetra 2-propoxide was diluted by 2-propanol and deionized water The TiO2/ZrO2 nanocomposite was synthesized from directly mixing Titanium dried gel into Zirconium gel. The reaction mixture was placed under ultrasonic irradiation probe for 2 hours. The filtrated composite gel was washed and calcinated at 500 °C for 3h in furnace. The FT-IR spectroscopy and the XRD study were exhibited that the crystal structure and purity of the TiO2/ZrO2 nano composite FESEM images were indicated the morphology and the average size of the NPs. The mean crystallite size of the NanoTiO2, nanoZrO2 and TiO2/ZrO2 nanocomposite were determined 57, 19 and 23 nm respectively. The photocatalytic performance was highly increased when nano-composite of TiO2/ZrO2 was used to degradation of Congo red (CR) solution. The TiO2/ZrO2 nano composite was shown higher photo-degradation efficiency than the pure nanoTiO2 and nanoZrO2.