Journal of Applied Research in Chemistry
Year:2019 | Volume:13 | Issue:1 |Papers Count:15

Due to the importance and applicability of the catalysts in the oil, automobile, pharmaceutical, polymer, and food industries, they are one of the important links between basic sciences and applied technology with new technologies. Nanocatalysts are more efficient and more active than homogeneous catalysts, and operate in milder conditions. They also have a higher selectivity. The ZnS-ZnFe2O4 magnetic nanocatalyst was synthesized for the first time by a simple procedure, and was characterized using energy-dispersive X-ray spectroscopy (EDAX), field emission scanning electron microscopy (FESEM), X-ray diffraction analysis (XRD), and vibrating sample magnetometer (VSM). Then, it was used for the efficient synthesis of 1, 2-disubstituted benzimidazole derivatives using 1, 2-diamines and various aldehydes in ethanol. This heterogeneous catalyst can be recovered easily and reused without any significant loss of the catalytic activity. The present methodology offers several advantages such as high yields of products, shorter reaction time, and use of environmentally-friendly solvent.

In this paper, CuMn2O4nanospinel was synthesized by sol-gel auto combustion method and characterized by X-ray diffraction (XRD), Fourier Transform Infra red (FTIR), BET specific surface area, scanning electron microscopy (SEM), Temperature-programmed reduction (TPR) and X-ray photoelectron spectroscopy (XPS). The catalytic performance of the nanospinel was evaluated in reduction of NO by CO and above 400 ° C the total of NO was converted. The correlation between physical-chemical properties and activity was investigated. The mechanism opf the reduction was determined at lower and higher temperatures. The XNO/XCO was around 2 at lower temperature, whereas it is around 1 at low temperatures. The results indicated that nano spinels could be promising and cheap catalysts for the process.

Recent studies show that nanoparticles of copper and copper compounds are effective antibacterial agents. Unlike silver, copper is an essential element for human health although in excess amount it has undesirable effects. In this study, the spherical structure of CuO nanoparticles was synthesized in the large mordenite matrix with solid-state reaction method. The samples were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, Transmission electron microscopy, Scanning electron microscope and BET. XRD results revealed diffraction peaks for each of the two compounds in the nanocomposite. In the FT-IR spectra, all bands in nanocomposite sample show a shift with respect to that of the matrix, indicating that the CuO is incorporated in the matrix. Transmission electron microscopy images showed small spherical nanoparticles belong to CuO nanoparticles with maximum diameter 22 nm. The zone diameters of CuO-large mordenite nanocomposite were 14 mm for Gram-negative (E. coli) and Gram-positive (S. aureus) bacteria.

In this research, a novel efficient heterogeneous and reusable catalyst was designed and synthesized through functionalization of halloysite nanotubes with ionic liquid. The catalyst was fully characterized by using various characterization techniques such as SEM/EDS, FTIR, XRD, TGA and BET. The results established that low amount of the catalyst could promote the reaction efficiently in relatively short reaction times, superior to many reported homogeneous catalysts. Moreover, the catalyst was reusable and could be reused up to four times with slight loss of the catalytic activity.

The use of ionic liquids along with alkanolamine-based solvents, as efficient absorbents with some of the improved properties, such as reduced solvent loss and easy regeneration performance in order to absorption and separation of carbon dioxide gas has been considered recently. Therefore, in this research, the experimental study of carbon dioxide solubility in aqueous solutions of monoethanolamine (MEA) and 1-hexyl-3-methylimidazolium nitrate ([Hmim][NO3]) ionic liquid in the form of quaternary systems with different weight percent as new absorbent solutions with an emphasis on the absorption capacity measurements were carried out. For this purpose, the measurements of vapor-liquid equilibrium were performed at a temperature range of 298– 343 K and pressures up to 40 bar using a static phase equilibrium apparatus. The results indicated that in all of the absorbent solutions, carbon dioxide solubility increased with decreasing temperature and increasing pressure. Moreover, by adding [Hmim][NO3] ionic liquid to MEA aqueous solutions, carbon dioxide solubility in absorbent solutions diminished relatively.

In this research, a series of mesoporous alumina (MA) nanostructured materials was synthesized by an evaporation-induced self-assembly using the mixture of nonionic surfactant PS-PVP and cationic surfactant CTAB in acidic and basic conditions. The aluminum source was aluminum-tri-sec-butoxide. The effects of surfactant type, pH and calcination temperature on the physical properties of the resulting MAs were investigated. The samples were characterized by N2 adsorption– desorption isotherms, X-ray diffraction (XRD) and scanning electron microscope (SEM). The results showed that the synthesized sample using mixture surfactants have high surface area and high pore volume in basic condition at 550 oC. Poorly soluble curcumin was selected as model drug to evaluate the release behavior from mesoporous alumina. Curcumin was loaded on MAs by the impregnation method. The in vitro release behavior of these compounds was studied in simulated gastric fluid (SGF, pH = 1. 2) and simulated intestinal fluid (SIF, pH = 6. 8). The release of insoluble curcumin was 90% within 12 h. Kinetics of released curcumin followed from Korsmeyer-Peppas model at the both of simulated fluids.

Cationic poly(3-acrylamido propyl) tri methyl ammonium chloride hydrogel was synthesized from (3-acrylamidopropyl) trimethyl ammonium chloride (APTMACl) as monomer, N, Nʹ-methylenebisacrylamide (MBA) as a crosslinker, ammonium persulfate (APS) as an initiators, and N, N, Nʹ , Nʹ-tetramethylmethylenediamine as an accelerator via free radical polymerization reaction techniques in mild condition. The morphology and porosity of the p(APTMACl) hydrogel was characterized by field-emission scanning electron microscopy (FE-SEM). The swelling percent of hydrogel was investigated in water. Palladium ions were loaded into hydrogel network, then, to reduced metal ions within hydrogel network, metal ions loaded hydrogels were treated with NaBH4 as reducing agent. Thermal properties of prepared nano-composit were characterized by thermal gravimetric analysis (TGA). To investigate the nanostructure, the sample was examined with TEM observations. The amounts of metal nanoparticles entrapped in hydrogels were calculated by AA spectroscopy. Catalytic activity of p(AA)-Ag catalyst was investigated in the aerobic oxidation of primary alcohols and reduction of nitro compounds. The catalyst was easily recovered from the reaction medium and it could be re-used for other five runs without significant loss of activity.

In this study, the optical-electrical properties and photoelectrochemical conversion efficiency of a bifacial sensitized solar cell containing of Polyaniline (PANI) deposited on TiO2 nanostructured film have been investigated. The PANI-based counter electrode was prepared by polymerization of aniline with an acid catalyst, while TiO2 film, as a photo-anode, was prepared at low temperature by the sol-gel chemical route and dip-coating process. The transparency of the prepared cell makes it possible to excite a higher density of color molecules through photochemical processes due to light exposure from both sides. Also due to the high light scattering by TiO2-corallike nanostructures and the high surface area of PANI nanofibers, it is expected that more electron transfer occurs between layers. These factors led to an increase in the conversion efficiency of the prepared cell in the presence of ruthenium-based molecules based on the N719 dye up to 22. 8%, which is more appropriate than that of a similar cell made with platinum electrodes (with a yield of 7. 75%). The low cost of manufacturing and the high optical transmission of up to 71% in the visible light region allow the use of PANI and TiO2 electrodes with special morphology to produce bifacial solar cells in an industrial scale.

CeO2/TiO2 core-shell nanoparticles are known as volatile compounds sensors. The sensing properties of these nanoparticles changes by doping with different elements. In this work, the titania shell of the CeO2/TiO2 core-shell nanoparticles was doped by different molar ratios of Zr4+ and V5+. The existences of cerium, titanium, zirconium and vanadium elements were confirmed by energy dispersive spectroscopy (EDS). Formation of ceria and doped titania nanoparticels were approved by field emission scanning electron microscopy (FESEM). High-resolution transmission electron microscopy (HRTEM) used to show the formation of core/shell structure. The sensing properties of prepared CeO2/TiO2 core-shell nanoparticles were thoroughly investigated in the presence of methanol, ethanol and 2-propanol. Compared with pure CeO2/TiO2 core-shell nanoparticle, the 2% vanadium doped CeO2/TiO2 exhibits enhanced ethanol sensing properties at room temperature. The sensitivity as a function of volatile organic compounds (VOCs) concentration was linear with suitably short response and recovery times at room temperature. The mechanism of sensor’ s response was described based on the depletion region. In summary, the results show that CeO2/V2%-TiO2 is the most suitable sensor for ethanol, based on the quantitative and qualitative measurement properties.

The removal of nitroaromatic explosive is of importance in low concentration of aqueous samples. These compounds are toxic and lead to genetic mutations in humans, fish and microorganisms. 2, 4-Dinitrotoluen (2, 4-DNT) is the most common nitroaromatic explosive material; it has a wide spectrum of applications in manufacturing many ammunitions because of its easy production. Molecularly imprinted polymers )MIP( are intelligent nano-systems which are formed in the presence of a target molecule and exhibit large chemical and exclusive affinity towards the target molecule, with their mechanism resembling that of anti-bodies or enzymes. Surface area to volume ratio in nanoparticles have a significant effect on the particle properties. MIP nanoparticles possesses many excellent characteristics such as high surface and low cost, easy synthesis, high stability under various physical and chemical conditions, and reusability. In the present study, nanoparticles of MIP were synthesized in an inverse suspension system using, polyvinyl alcohol (PVA) as functional polymer, 2, 4-DNT as the template and glutaraldehyde as the cross-linker. The nanoparticles of MIP were characterized using scanning electron microscopy (SEM), attenuated total reflectance fourier transform infrared spectroscopy (ATR-FTIR). All of the absorption bands appeared in ATR-FTIR spectroscopy indicated the aldehyde reaction between PVA and glutaraldehyde and the formation of MIP nanoparticles. The SEM micrograph showed the average size of the synthesized polymer nanoparticles to be 45 nm with a relatively uniform particle size distribution. The saturated adsorption capacity could reach to 11. 91 mg. g− 1 and the selectivity coefficients relative to DNT is 14. 04.

Ionic liquid-based dispersive liquid-liquid microextraction and HPLC were applied for extraction, preconcentration, and determination of 3-indole butyric acid in pea plant samples. The effect of some factors such as chemical structure of ionic liquid, pH of the sample solution, temperature, extraction time, centrifugation time, volume of ionic liquid, and volume of aqueous sample solution were studied. Percent extraction of 3-indole butyric acid was strongly affected by pH of the sample solution, chemical structure of the ionic liquid, ionic strength of sample solution, and temperature. Back-extraction of 3-indole butyric acid from ionic liquid phase to basic aqueous solution were also studied. Preconcentration factor of 40 was obtained before HPLC analysis of real samples. The calibration plot ranged from 30. 4×10− 2 to 38. 6 mg L-1 of 3-indole butyric acid. The LOD (based on 3s) was 29. 3×10− 2 mg. l-1. The RSD for suggested method was calculated as 1. 8% at 20. 3 mg. l-1 of 3-indole butyric acid. It was found that each IL phase was reusable for at least four microextraction/back-extraction cycles. This method was successfully applied for extraction of 3-indole butyric acid in pea plant samples.

Starch and cellulose are naturally abundant biodegradable polymers. Starch has disadvantages such as weak barrier properties against water and poor thermal properties. Polyvinyl alcohol (PVA) is anticipated to be a good candidate for incorporation into these natural polymers. Also PVA shows high resistance to solvents and good barrier properties to oxygen. Because of their weak barrier properties of Starch or carboxymethyl cellulose and PVA polymeric blend other approach is needed. Making nanocomposites by adding nanoclay to improve barrier properties of these films is a new way. In this research, nanocomposites of carboxymethyl cellulose/polyvinyl alcohol/clay and starch/polyvinyl alcohol/clay at three different weight percentage of PVA (15, 30, and 45) and two nanoclay level (5 and 10) were prepared and their films were made after drying. Optical and thermal properties of the nanocomposites were investigated using UV-Vis spectrophotometry, thermogravimetry analysis (TGA/DTG). The energy gap of the samples was calculated using the graph (α hν )2 against hν and tauc equation. The results showed that addition of PVA and nanoclay increased the thermal resistance of nanocomposite. The energy gap of the nanocomposites films is obtained less than the 5 eV, indicating that these nanocomposites has the potential to use in electronic components such as diodes.

This work reports, microwave synthesis and characterization of NiO-nanoparticles in the presence of sodium dodecyl sulfate (SDS) as a stabilizer agent. Ni(NO2)2 and NaOH powder have been used as starting reagents. Particle size distribution and characterization of products were done by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and EDX analysis. NiO-nanocomposites functional groups were deduced by FT-IR spectroscopy. Also, the efficiency of NiO-particles as a new optical material using UV-VIS spectroscopy has been evaluated. Subsequently, synthesized nanoparticles as nanocatalyst were used for the preparation of benzopyran derivatives via one-pot three-component of dimedone, malononitrile and various types of aromatic aldehydes in methanol as solvent. The results confirmed that this nanoparticle are good catalyst for benzo-pyran synthesis after reaction condition optimization.

An ultrasonic promoted facile and convenient procedure for the synthesis of N-aryl nucleobases and other N-heterocyclic derivatives using Cu/aminoclay/reduced graphene oxide nanohybrid as an efficient heterogeneous nano-catalyst has been described. In this approach, room temperature ultrasonic mediated N-arylation reaction of nucleobases and other N-heterocyclic compounds with aryl halides (bromide and iodide) bearing diverse functionalities catalyzed by Cu/aminoclay/reduced graphene oxide nanohybrid in the presence of Cs2CO3 in DMSO at room temperature furnishes the corresponding N-aryl derivatives in good to excellent yields. Utilizing ultrasonic irradiation technique provided the dramatic improvements in terms of higher yields and shorter reaction times compared with conventional heating method. The use of mild reaction conditions, short reaction time, recoverability and reusability of catalyst, and simple purification process are important advantages of the present method.

In this study the substituted strontium hexaferrite with formula SrFe11. 1(ZrZn0. 5Co0. 5)0. 45O19 was firstly synthesized by a sol-gel auto combustion method. Then the ternary nanocomposite of polyaniline/ SrFe11. 1(ZrZn0. 5Co0. 5)0. 45O19/multiwalled carbon nanotubes ( MWCNTs) was prepared by insitu polymerization method. The structure and surface morphology of substituted hexaferrite, and nanocomposite were investigated by using X-ray diffractometer ( XRD), Fourier transform infrared spectroscopy ( FTIR), and field emission scanning electron microscope ( FESEM). The results showed that the substituted hexaferrite and multiwalled carbon nanotubes were effectively coated by polyaniline chains. The magnetic properties of samples were measured by the vibrating sample magnetometer ( VSM). The measured magnetic values decreased from (Ms=60 emu/g, Mr=30emu/g) for substituted hexaferrite, to ( Ms=11. 5emu/g, Mr=6emu/g) for nanocomposite. The microwave absorption properties of samples were determined by vector network analyzer ( VNA). The results indicated that the minimum reflection loss value of the nanocomposite is-30 dB at 10. 1 GHz with appropriate bandwidth in the range of X-band. The reflection loss measurements demonstrated that the nanocomposite has good potential as a microwave absorbent.