نشریه پژوهش های شیمیایی و نانو مواد
پیاپی 3 (پاییز 1401)

Cobalt immobilized on amine-functionalized magnetic cellulose nanofiber (Fe3O4@CNF-NH2-CoII) was synthesized as a new bio-based nanocatalyst. The synthesized catalyst was characterized by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), energy diffraction X-ray spectroscopy (EDX), transmission electron microscopy (TEM), thermal gravimetric analysis (TGA), vibrating sample magnetometry (VSM) and inductively coupled plasma atomic emission spectroscopy (ICP-OES) and its morphology was identified. This magnetic nanocatalyst acted well for efficient synthesis of benzimidazole derivatives through the condensation reaction of aromatic aldehydes and aryl 2,1-diamines by using of ethanol as a solvent under air atmosphere. This nanocatalyst was successfully recycled by an external magnet up to 5 times and reused without a significant decrease in its activity. The use of green solvent, good product efficiency, the use of the recovered nanocatalyst without losing catalytic activity and the simple synthesis method present this method environmentally and economically favorable for synthesis of benzimidazoles.

The main goal of all reservoir simulators is to predict the flow performance and oil recovery factor. Most commercial simulators solve the equations governing reservoir behavior with the finite difference approach. To solve the three-dimensional equations of flow in a porous media with the finite difference method, the grid dimension has an effect on the simulation results (i.e., divergence). In addition, the simulation of complex reservoirs with a large number of network blocks needs a long computational time. In order to eliminate the effect of block size and increase the speed of simulation, the streamline method has been proposed, which is widely used in the management of hydrocarbon reservoirs. The streamline method can monitor the flow direction in the reservoir, injection efficiency, pore volume, and well allocation coefficient to determine the volume of fluid transferred between injection and production wells. Also, in recent years, many studies have been conducted on the effect of nanofluid injection on the characteristics of oil reservoirs and the increase in oil recovery. Since the streamline method has not been used to simulate the nanofluid injection in oil reservoirs, in this research the effect of water-silica nanofluid injection on the flow equations of phases has been investigated. The simulation results showed that nanofluid injection into the reservoir is more effective than pure water injection and increases oil production. Moreover, it was observed that the reservoir oil type (light and heavy) has an insignificant effect on the simulation results.

In the present paper, a simple, and reliable method for the preconcentration of cadmium ions based on dispersive liquid-liquid microextraction technique is introduced. A new task specific ionic liquid (TSIL) was used as an extractant for the selective preconceration of Cd2+ ions from aqueous solution and determination by flame atomic absorption spectrometer (AAS). Parameters affecting the extraction of Cd2+ ions such as pH solution, TSIL concentration, centrifugation time, hydrophobic salt concentration, nonionic surfactant concentration, and ionic strength were optimized. Under the optimal conditions, the calibration curve was linear in the concentration range of 5 - 250 µg L-1 with a detection limit of 0.42 µg L-1 Cd2+. Since, TSIL has a high affinity toward cadmium ions, interferents have little effects on the microextraction, so satisfactory recoveries were obtained for the extraction of trace amounts of cadmium ions from real samples (blood serum, milk and honey).

In this research, cheap, eco-friendly and reusable catalysis has been synthesized with a suitable method. For this purpose, firstly, chitosan particles were prepared through the process of deacetylation from Persian Gulf shrimp shell waste, and then the copper-based complex was successfully obtained on a bed of chitosan particles. The structure of chitosan-copper(II) complex was confirmed by using of various techniques such as Fourier transform infrared spectrometry analysis, X-ray diffraction, scanning electron microscopy, X-ray energy diffraction spectroscopy and visible-ultraviolet spectroscopy. Considering the wide application of benzimidazoles in industry and pharmaceuticals, the catalytic properties of the chitosan-copper(II) complex in the two-component reaction of the synthesis of various benzimidazole derivatives were studied under solvent-free conditions. The use of chitosan-copper(II) complex catalyst in the synthesis of benzimidazole derivatives showed several advantages, including significant efficiency, mild reaction conditions, short reaction time, easy separation of the catalyst and avoiding the production of toxic waste. Furthermore, the chitosan-copper(II) complex was easily recovered by filtration and could be reused for five cycles without loss of catalytic activity.

In this paper, graphene oxide is applied as a substrate for the synthesis of the magnetic graphene oxide-zinc oxide nanocomposite. The prepared nanocomposite (GO–ZnO–Fe3O4) are characterized using Field emission scanning electron microscopy(FESEM) and vibrating sample magnetometer(VSM). The photocatalytic performance of the synthesized samples is evaluated according to the photodegradation of methylene blue and methyl orang as organic dyes pollutant. The results of studies on the removal of dye pollution with a UV-Vis spectrometer showed that the removal of methylene blue dye is done completely in a short time and in the presence of sunlight. One of the advantages of the above nanocomposite is its very cheap, convenient and cost-effective synthesis.

Today, along with the progress of the industry, water pollution is also increasing. Pollutants enter the underground sources and surface waters from various routes and become a potential threat to human health and other organisms in the life cycle. Although various methods have been used to purify water and wastewater, most of these methods are not effective enough to remove many persistent organic pollutants, such as dyes, drugs, solvents, pesticides, etc. Antibiotics are among persistent organic pollutants that are rarely completely metabolized in the body after consumption, and 30 to 90% of them remain as active pollutants in the environment after elimination. Therefore, the use of new methods such as photocatalytic processes for antibiotics treatment have attracted the attention of researchers. The use of heterogeneous semiconductor nano photocatalysts as one of the advanced oxidation processes is considered due to their advantages including short-time procedure for synthesis of nano photocatalysts, nano photocatalyst ability to recycle and reuse, the formation of harmless products during the reaction, economic efficiency and compatibility with the environment. So, this approach can be an effective and efficient way to deal with environmental pollution caused by antibiotics. In this article, in addition to introducing the advanced oxidation method, recent studies on using of heterogeneous nano photocatalysts and most effective factors on photocatalytic reaction in water and wastewater treatment containing antibiotics have been reviewed.