نشریه شیمی کاربردی روز
پیاپی 64 (پاییز 1401)

In this work, the ability to selectively separate CO2 from N2 with a similar composition of flue gas by graphtriyne three-layer membrane was studied using molecular dynamics simulation. For this purpose, two sets of NVT and NPT ensembles were used. In the NPT ensemble, gas molecules were located on either side of the membrane and in the NVT ensemble, gas molecules were located on one side of the membrane. Then the effect of different temperatures and pressures in NPT ensemble and the effect of different temperatures and initial pressures in NVT ensemble on the membrane's ability to separate CO2 from N2 were investigated. The results showed that although the size of the graphtriyne pores were large enough for these molecules to pass through, in both ensembles, more CO2 molecules were adsorbed between the graphtriyne layers. It was also found that with increasing the temperature, the adsorption of N2 molecules decreased more than CO2 molecules, thus increasing the selectivity of CO2 uptake compared to N2 between graphtriyne layers. As the pressure increases, although the percentage of trapped CO2 molecules passing through the layers increases, the membrane still retains the selectivity of CO2 uptake relative to N2. Therefore, graphtriyne three-layer membrane can be introduced as very suitable and efficient for separation of CO2 from N2.

In this research, a novel, low-cost and environmentally friendly nano zeolite clinoptilolite as a catalyst with high thermal stability and reusability was synthesized by an efficient method. For this mind, initially, nano zeolite clinoptilolite synthesized. In continuation of research, a three-stage reaction of nano zeolite clinoptilolite with 3-chloropropyltrimethoxysilan, hexamethylenetetramine and chlorosulfunic acid compounds desired functionalized nanoclinoptilolite NCP@SiO3PrHMTA-SO3H (D) was obtained. The structure of this synthetic functionalized nanoclinoptilolite was confirmed using various techniques such as; XRD, FT-IR, EDS and SEM analyses. Due to, widespread application of xanthene’s in pharmacology and industrial fields, the catalytic activity of the synthetic nano clinoptilolite was studied for the three-component synthesis of different xanthene dione derivatives under solvent-free conditions. In the presence of this novel synthetic nanocatalyst, desired products were synthesized with excellent yield, short reaction time with high purity. The structure of prepared xanthene dione derivatives was characterized by spectroscopic data and melting point.

In the present work, nickel-iron layered double hydroxide was prepared by the hydrothermal method. The synthesized electrocatalyst was studied using X-ray diffraction pattern, infrared spectroscopy, nitrogen absorb-desorption, and scanning electron microscopy. The results confirmed the synthesis of a high surface area electrocatalyst. In the next step, the electrocatalytic activity of the synthesized sample was investigated by dropping the sample on the glassy carbon electrode at neutral media. The voltammetric results show a decrease in the onset potential and overpotential of hydrothermal nickel-iron layered double hydroxide in compared to the nickel-iron layered double hydroxide which was synthesized by the co-precipitation method. High surface area, low onset potential, high stability, and repeatability are the prominent features of this electrocatalyst.

In this work, two magnetic nanocomposites of zinc ferrite coated with polyaniline (PA/ZnFe2O4) and cobalt ferrite coated with polyaniline (PA/CoFe2O4) were synthesized by sol-gel method and in situ polymerization. These nanocomposites were characterized by various identification techniques including SEM, FT-IR, XRD and EDX. These nanocomposites were used to remove Congo red. The effect of polyaniline presence was also investigated and the results showed that the presence of polyaniline polymer coating on the surface of nanoparticles had a significant effect on the process of adsorption of Congo red. The prepared nanocomposites could omitted the Congo red in eques solution of 50 ppm, at mild reaction condition at 180 min in pH=7 by the using of 15 mg absorbents up to 90 and 97%, respectively. Also, the synthesized nanocomposites were used to remove the Congo red from real samples including well water and dyeing wastewater. The results have been shown that the complex matrix has no any effect on nanocomposites efficacy and both nanocomposites were reusable for 4 times. Therefore, synthesized nanocomposites due to their ease of synthesis, and abundance and cheapness of raw materials are good candidates for removal of congo red in real samples and complex matrix on industrial and semi-industrial scales.

Na[Ln(edta)(H2O)n] (Ln = Dy, Ho, Yb and Er, n = 1-3) complexes were synthesized using lanthanide salts and Na4(edta). The synthesized lanthanide complexes were characterized using different techniques including elemental analysis, UV-Vis, FT-IR and fluorescence spectroscopy. Their structures were also optimized using DFT method. Then, the complexes were refluxed in the presence of a mixture of Al(OH)3 and H3BO3 for 24 h. The reaction mixture was then calcined at 400°C for 5 h. The obtained powder as a new phosphorescent pigment was dispersed in water and acrylicpolyurethane resin, and new phosphorescent pigments were finally prepared by adding different percentages of lanthanide oxides to the original pigment. The prepared phosphorescent pigments were investigated using XRD, XRF, and solid state phosphorescence spectroscopy.

A simple and selective method for the preconcentration of Fe(III) and Zn ions prior to flame atomic absorption spectrometric (FAAS) determinations using a column packed with nano graphene oxide (GO) as a solid-phase extractant has been presented in this manuscript. The method is based on the sorption of mentioned ions on synthesized GO with use of Methyl-2-(4-methoxy-benzoyl)-3- (4-methoxyphenyl)-3-oxopropanoylcarbamate) as chelating agent. Some effective parameters on the extraction and complex formation were selected and optimized. Under the optimized conditions (pH 9, flow rate 9 mL min−1), metal ions were retained on the column, then quantitatively eluted by 5 mL 3.0 mol L−1 HNO3 solution. The preconcentration factor was calculated as 240. The detection limits for the understudy analyte ions were found in the range of 0.22 ng mL-1 to 0.28 ng mL-1 (for Fe3+ and Zn2+, respectively). The column packed with GO was good enough for metal ions separation in matrixes containing alkali, alkaline earth, transition and heavy metal ions. This method was also used to determine the recovery rate of the studied ions in real samples.

Pheromones are the secreted or excreted chemical factor that triggers a social response in members of the same species. Pheromones are chemicals capable of acting outside the body of the secreting individual to impact the behavior of the receiving individual. Terrestrial snails are one of the major pests that cause significant damage to crops. These snails use volatile pheromones to communicate with each other, thereby exchanging various messages between members of their species. Pheromones are able to stimulate message recipients outside the body that produces the message and influence their behavior. Herein, the volatile pheromones that play a major role in the communication between snails of a particular species were investigated. To this end, the pheromones were extracted using liquid phase extraction technique and identified by gas chromatography-mass spectrometry instrument (GC-MS). First, a specific species of the snails were selected, the samples were collected and the pheromones were evaluated. Finally, by comparing the obtained peaks with the reference peaks related to pheromones, the pheromones were identified. The extraction was performed using LLE. The identification was also performed using GC-MS. The results indicated that 2-(3,4-Dimethoxyphenyl)-2-methoxy-N,N-dimethylethanamine, 3,4-Octadiene, 7-methyl-, 2-Pentadecanone- 6,10,14-trimethyl، 4-Hexadecen-6-yne, (E)-، Dimethyl aminomethyl (triethyl) stannane, desmosterol, 2,3-dihydroxypropyl ester, 3,4-Octadiene, 7- methyl- and 4-Methyl-2,5-dimethoxybenzaldehyde are the responsible pheromones. The present study is an experimental study in which the volatile pheromones that play a role in the communication between snails of a particular species were investigated. As a result, the identified pheromones can be used to make pheromone traps.

Dye-sensitized solar cells (DSSC) are among the interesting generations of solar cells that require further research to achieve industrial production. Current platinum (Pt) counter electrodes used in DSSCs is expensive and should be replaced by cheaper materials. In this study, we propose the tin-selenide (SnSe) material prepared on ITO substrates by the electrodeposition method as a Pt replacement. Our prepared materials demonstrated excellent electrocatalytic behavior and charge transport with iodide/triiodide electrolyte that is confirmed by cyclic voltammetry and electrochemical impedance spectroscopy. Our best DSSC reached efficiency of 4.9% that was slightly lower than the DSSC fabricated with Pt counter electrode. Therefore, our study shows that the low cost and earth-abundant SnSe prepared by the electrodeposition method is a suitable replacement for Pt in DSSCs.

Nano materials are now used in different industries as they can solve many environmental issues. In this line, cooling towers as important parts of petrochemical industries have always received special attention where their role in increasing the environmental issues are taken into account. In this study new samples of organic-metallic nickel nanostructures were synthesized as new nanofluid options in the field of dry cooling towers and using ultrasonic method. Synthetic samples were analyzed by SEM, XRD and FTIR analyses. The results showed that the nanofluids developed have a uniform morphology and that their crystal properties were confirmed by the XRD model. As the application of nanofluids in the dry cooling tower is expected; hence, they can improve the thermal specifications and that the analysis results of TG-DSC confirmed this claim.

The efficiency of medlar core powder as a low-cost adsorbent for removing a cationic dye methylene blue (MB) from aqueous solution has been investigated by using batch mode and continuous systems experiments. The effects of different parameters namely amount of adsorbent, initial dye concentration, contact time, temperature and pH solution of dye solution have been studied to understand the adsorption behavior of the adsorbent under various conditions. Various techniques for characterizing the adsorbent have been applied including, zero point charge measurement (pHpzc), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The experimental isotherm data have been analyzed using Langmuir and Freundlich isotherm equation. Methylene blue adsorption fitted the Langmuir isotherm. The kinetic results of adsorption obeyed a pseudo-second order model. Thermodynamic parameters including the Gibbs free energy ΔG°, enthalpy ∆H° and entropy ∆S° have revealed that the adsorption of methylene blue on the medlar core powder is feasible, spontaneous and endothermic. The maximum removal percent 25mL of methylene blue solution is 96.4% for 100 mɡ/L of MB under conditions, pH=7 at a temperature 25 °C and 0.08 ɡ/L of adsorbent.

In this study, a carbon paste electrode with a composite of NiFe2O4 and cross-linked chitosan (NF@Ch) was used as a simple, rapid and sensitive method with a modified carbon paste electrode (mCPE) for study and determination of Atorvastatin (ATV) content in different samples. At first, the effect of some experimental parameters such as the percent of carbon paste, pH of electrolyte, the scan rate and accumulation time on electrochemical behavior of the drug was independently evaluated and optimized. The electrochemical oxidation mechanism of the drug on the surface of the modified electrode was obtained by the resulted cyclic voltammograms in different scan rates and pHs. In the next step, differential pulse voltammetry was used for detection of atorvastatin in the optimized condition. The response of the mCPE to ATV was found to be linear from 0. 1 nM to 5.0 nM and also from 5.0 nM to 100.0 nM and the sensor had a limit of detection (LOD) of 35 pM. Also, the successful application of the modified electrode in real samples (tablets) was evaluated and appropriate accuracy was obtained.

Azolo-annulated pyrimidines have attracted continuing interest due primarily to their structural similarity to heterocyclic bases of DNA and RNA. As a consequence, these compounds can act as antimetabolites, being effective biologically active compounds. Numerous advantageous properties of azolopyrimidines such as important industrial, agrochemical and pharmaceutical applications, especially in biological science, material chemistry and medicinal chemistry impelled us to design and synthesis of a number of various and interesting derivatives of 3-alkyl-9-methyl-tetrazolo[1,5-a][1,2,3]triazolo[4,5-d]pyrimidine as a novel heterocyclic system which has not been reported previously. In the present work, initially the reaction of 2,4-dichloro-6-methylpyrimidin-5-amine (1) with different primary amines in refluxing i-PrOH gave the corresponding sec-amino derivatives (2a-e) which were consequently treated with NaNO2/HCl solution to yield quantitatively the corresponding diazo derivatives of 5-chloro-3-alkyl-7-methyl-3H-[1,2,3]triazolo[4,5-d]pyrimidine (3a-e). Further reaction of compounds (3a-e) with NaN3 in EtOH was resulted in various derivatives of novel heterocyclic system of tetrazolo[1,5-a][1,2,3]triazolo[4,5-d]pyrimidine (4a-e) that are in equilibrium with azide forms.