فصلنامه نانو مقیاس
سال هشتم شماره 2 (پیاپی 30، تابستان 1400)

In this paper, Graphene was exfoliated and doped simultaneously with magnetic metals and their oxide derivatives based on electrochemical method. The electrochemical properties of the as-prepared samples are investigated as advanced electrode materials for supercapacitors which was coated on nickel foam substrate. The structure and composition of the synthesized samples were studied by X-ray diffraction (XRD), Energy-dispersive X-ray spectroscopy (EDS) and Raman spectroscopy. The morphologies were characterized by field emission scanning electron microscopy (FESEM), Transmission electron microscopy (TEM) and High-resolution transmission electron microscopy (HRTEM). Cyclic voltammetry and galvanostatic charge-discharge measurments have shown that the behavior of the synthesized material is battery-like. According to the results of the specific capacity at different scan rates of 5, 10, 20, 30, 40, 50 and 70 mV/s in 1 M KOH, the highest capacity related to the scan rate of 5 mV/s, which has a capacity equal to 1124.63 F/g.

In this study, efficiency of sonophotocatalytic process by CMCD-Fe3O4@TiO2 in order to remove of PCB compounds from transformer oil were investigated by applying the response surface methodology (RSM) in the central composite design (CCD). Then, the effect of important parameters such as catalyst dosage, time, temperature and oil to ethanol ratio were investigated to optimize the maximum PCBs removal. The concentration and types of PCBs congeners in the contaminated oil were determined using a gas chromatography equipped with electron capture detector (ECD) and mass spectrometer (MS). Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) were used to examine the physical and chemical properties of synthesized photocatalyst. Based on the statistical results, the removal efficiency of PCBs was achieved 98 % in the optimum conditions of catalyst dose of 7.74 mg/mL, temperature of 25 °C, exposure time of 15 min and ratio of oil to ethanol 1: 5. Among the parameters studied, temperature and ethanol (p <0.0001) had the greatest effect on PCBs removal rate. The experimental results suggests that the use of CM-β-CD-Fe3O4@TiO2 in the presence of ultrasound waves possess a high efficiency in the removal of PCB compounds and can also be used an ideal and promising method on an industrial scale for purification of PCB compounds from contaminated transformer oil.

In the present study, HKUST-1 magnetic nanocomposite was prepared using the hydrothermal method and pre-synthesis modification. The aforementioned magnetic nanocomposite was characterized by the FT-IR, SEM, XRD and VSM techniques. In addition, the ability of this metal-organic framework to remove of the non-steroidal anti-inflammatory drug, Meloxicam, from aqueous solutions was studied. The widespread application of Meloxicam and the inefficient treatment of wastewater have resulted in the detect of the drug in water resources which can affect human health and/or ecosystems negatively. Therefore, the removal process of meloxicam was investigated by Fe3O4@HKUST-1 as the sorbent. Thus, the effect of variables factors on the removal process such as pH (7), absorbent weight (0.7 mg) and absorbent and absorbed proximity time (3 min) were optimized by the Central Composite Design at Design Expert software (10.0.7 version), the optimal conditions with desired function were obtained by the response surface methodology. Investigating the absorption isotherm confirms the adsorption behavior based on Freundlich and Langmuir isotherm. The most important advantages of the proposed nanocomposite as the absorbent include fast absorption process, low costs, high efficiency due to the large surface area and the porous structure of the Metal-organic framework. The resulted data showed the high removal efficiency (93.14%) and adsorption capacity (125.11mg g -1 ) of the proposed sorbent.

Propargylamines derivatives have been reported to possess a wide range of pharmaceutical activities or can be converted to some compounds with similar properties In this project, sulfamic acid stabilized on silica coated Fe3O4 magnetic nano particles was prepareded and characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), thermal gravimetric analysis (TGA). Then this catalyst used as a magnetically retrievable catalyst in the synthesis of different propargylamines by the reaction of various aldehydes, secondary amines and terminal alkynes at 80 °C under solvent-free conditions in high yields. This method is not only high yields and low cost due to solvent free conditions, but also due to having magnetic core catalyst can be easily separated using an external magnetic field and reused up to five times. It is worth noting that the difference in yields between the first and fifth catalyst recycling was less than 12%.

Magnetic nanoparticles of nickel ferrite were synthesized through a solid-state procedure and then calcined at high temperatures. In order to prevent oxidation and aggregation and also increase the quantity of functional groups on the surface of nanocatalyst, the NiFe2O4 nanoparticles were modified by copper hydroxide in alkaline medium and magnetic nanocomposite of NiFe2O4/Cu(OH)2 was successfully obtained. The synthesized magnetic nanoparticles were characterized by VSM, FT-IR, EDS, SEM, TEM and XRD techniques and then used as a new catalyst in the one-pot efficient conversion of different epoxides bearing aryl, allyl and alkyl substituents to the corresponding β-chloroesters in the presence of nickel chloride and acetic anhydride at room temperature under solvent-free conditions. Synthesis of β-chloroesters was carried out within 10-32 min with 80-96% yields. The magnetic nanocatalyst was easily separated using a simple magnet and reused in consecutive cycles without any significant loss of catalytic activity or magnetic property.

High optical response and anisotropy in electrical and optical properties, adjustable Schottky barrier, make Monolayers TiS3 as a candidate material to fabricate sensitive photo detectors, integrated convertors and polarized light emission devices. To Study of applications, transport is avoidable, This paper, studies transport of Monolayers TiS3 channel by the non-equilibrium green function method (NEGF) with DFT in TranSieta package. A device composed of 2 Au electrode and 13-unit cell as channel of TiS3 monolayer was simulated. Calculation of I-V curves reveals negative resistant from 1.6 V to 1.8 V as bias voltage in electrodes. To explain this events, study of PDOS, shows quality of charge carriers in negative interval, has been reduced which result in negative resistant.

Dyes are scientifically and generally a new type of environmental pollutions, which has caused worldwide concern. Many research has been done in this field to remove dyes from wastewater based on the adsorption process via nano-adsorbents. This study described the synthesis of a new magnetic nano-adsorbent based on chitosan hydrogel beads to remove methylene blue as the cationic dye from aqueous solutions. Chitosan hydrogel beads were cross-linked with cellulose and synthesized in the presence of magnetic bentonite nanoparticles (Fe3O4\Bent). Fe3O4\Bent nanoparticles were obtained from the synthesis of Fe3O4 magnetic nanoparticles in the presence of bentonite nanoclay by co-precipitation and in situ method. The structure of nano-adsorbents were investigated by FT-IR, XRD, FE-SEM, TEM, and VSM techniques. The adsorption capacities of hydrogel beads for Methylene blue dye were studied via different important parameters including the effect of pH, contact time, the effect of initial dye concentration and the effect of temperature. The results showed that the kinetic data and adsorption isotherm were best-correlated to the pseudo-second-order model and Langmuir model, respectively. The thermodynamic data (ΔG, ΔS, and ΔH) indicated that the adsorption process was spontaneous, favorable and endothermic.

Recent advances in synthesis of nanoparticles have paved the way for the development of new nanocomposites with new and unique properties. Precise control of the basic structures of nanoparticles, such as size, shape or formulation, enables us to make composites of these nanoparticles that have superior properties. In this study, a nanocomposite containing cadmium telluride quantum dots in a polyvinyl acetate matrix was synthesized and the capabilities of this nanocomposite as a gamma sensor were studied. Gold nanoparticles were then synthesized and characterized. Three- component nanocomposite of gold nanoparticles / cadmium telluride quantum dots in a polyvinyl acetate matrix was prepared and the properties of this nanosensor against gamma radiation were investigated. The results showed that three-component nanocomposite containing gold nanoparticles have better and more sensitive performance than two-component nanocomposite.

This paper studies the defects graphene and diffusion of helium gas through nanoporous graphene membranes in the presence of natural gas. Due to study the doping effect on to the diffusion process, the helium gas atom passes through the created cavities in the doped nanoporous graphene membranes of C90H27, C90H30, C90H24, and C87H24F3. Because of Helium is one of the most important industrial gases and its separation is important in oil, gas and petrochemical industries. the present study can be used as a theoretical study to develop a new and important industrial method for separation helium in the Presence of Natural Gas. Suitable defective graphene was used as the selective membrane for helium gas release in the presence of natural gas containing methane, nitrogen, hydrogen, helium and carbon dioxide. All DFT calculations were performed using the Gaussian 09 program. The results analysis using (AIM) and (NBO) showed that C90H24 has the highest probability of helium passing through natural gas. Finally, the inlet and outlet concentrations of the pore were investigated to determine the amount of helium. According to this study, it is suggested that this result could be a good solution for extracting helium from natural gas in oil wells.

Ricin is a toxic glycoprotein, it consists of two subunits (RTA&RTB). There are two vaccine candidates based on RTA included RiVax and RVEc. Although different studies about immunized potency of RiVax, alone and with adjuvant, have been performed, but novel delivery system like nanoparticles to improve immunization of this protein has not been used until today. The purpose of this study was the synthesis of alginate nanoparticles (NPs) containing RiVax and evaluation of physicochemical parameters and immunization potential of this system as compared to naked RiVax. In this research, after purification of RiVax, Ionic gelation method was used to prepare alginate nanoparticles, which is a simple and suitable method for heat sensitive materials.Then, NPs containing RiVax and naked protein was administrated into different groups of mice. 8weeks after last immunization, the mice were analyzed. Results showed that the size of NPs was 190nm and the release pattern of protein from nanoparticle is slow (12%of protein during 40days). Also, immunization results showed that NPs containing RiVax compared to naked RiVax could not stimulate the immune system interestingly. We concluded that the alginate NPs could not be able to make a remarkable immune response compared to protein alone due to the slow release of RiVax from them.

In this research, manganese ferrite (Mn), calcium ferrite (Ca), and zinc ferrite (Zn) nanoparticles were synthesized by thermal treatment method. Curcumin (CUR) loading and release rate of Mn, Ca, and Zn nanocarriers were investigated at different pHs. The drug loading percentage in Mn nanocarriers were higher than Ca and Zn, which is the result of neutral manganese ferrite in the loading medium. Strong π-π interaction between CUR and manganese ferrite nanocarriers increases drug loading percentage. By changing the pH from 7.4 to 5.5, the release of curcumin from Mn, Ca and Zn nanocarriers increased from 41, 24.7, and 44% to 92, 58.7, and 53%, respectively. The biocompatibility of Mn, Ca and Zn nanocarriers were determined using the MTT method, hemolysis test, and lethal dose test. Studies have shown that although a high percentage of MCF-7 cancer cells are destroyed in the presence of Zn nanocarriers, these nanocarriers have a destructive effect on normal HEK-293 cells.

In pharmacy, the issue of drug delivery is an essential part of drug design and production. In the last decade, nanotechnology has emerged as a new approach to radiopharmaceutical delivery. In this study, magnetite nanoparticles were synthesized and then their surface was modified using thioglycolic acid. It was then labeled with gallium-67 radionuclide. The results of TEM and SEM imaging showed that the average size of nanoparticles is 20 nm, which is a suitable size for biological applications. The results showed that 98% of the labeled nanoparticles were stable for up to 4 hours in the chemical synthesis and human serum albumin medium. Nanoparticles were injected into rats and the uptake and excretion from body was investigated. The results showed that the surface modification of nanoparticles completely changes their absorption and excretion behavior and the prepared nanoparticles have full compatibility and good stability, which, as a result, introduces this nanoparticles as a suitable agent for clinical diagnostic methods.

In this study, titanium dioxide (TiO2) containing 1 wt% of various elements (Ag, Cr, Cu, V, or Pt) was synthesized by a one-pot sol-gel method. The produced materials were extensively characterized by means of X-ray diffraction (XRD), BET surface-area measurements, Raman spectroscopy, UV-Vis spectroscopy and Transmission electron microscopy (TEM). UV-Vis spectroscopy demonstrated a clear shift in the absorbance of modified TiO2 towards the visible light region. The photocatalytic performance of the prepared materials was evaluated in the photooxidation of methylcyclohexane (MCH) under the illumiation of UV or Visible light. The performance was monitored by in situ ATR-FTIR. The best catalytic performance was obtained when Cr/TiO2 was applied. The photocatalytic activity under visible light illumination could be further enhanced by photodeposition of Pt nanoparticles (0.06 wt % Pt) on the surface of Cr/TiO2. The origin of the synergetic effect of Cr6+ and Pt nanoparticles will be discussed.

: In this paper, a transmissive metasurface flat lens is proposed for silicon thin film in solar cells to focus and trap light in the active layer of the cell. Designing metasurface lens is based on the generalized Snell's law, and analyzed using CST simulation. The structure is investigated at the interested wavelengths of solar spectrum and for a wide range of angles of incidence at both TM and TE polarizations. The numerical results show that the transmissive lens increases the absorption in a wide large of wavelengths for both TE and TM polarizations of the incident light, resulting in a short circuit current enhancement of 39% and 32% for TM and TE polarizations, respectively.

Electrochemical synthesis of water-soluble gold nanoparticles with sizes smaller than 10 nm in a green condition is reported. A sacrificial gold anode in the presence of glutathione as a protecting ligand was used under constant current condition. The electrogenerated gold (III) ions were reduced by hydride ions and decorated by glutathione, resulted in the formation of bio-compatible gold nanoparticles. The produced nanoparticles were characterized using different techniques, including Uv-vis spectroscopy, transmission electron microscopy (TEM), and X-ray diffraction (XRD). TEM analysis indicates that the size distribution of nanoparticles is in the range of 4.0 to 7.0 nm. This work provides a new way to produce biocompatible gold nanoparticles.

Dyes colors are one of the most important organic pollutants in the industry which cause a lot of environmental problems. Therefore, the determination and removal of dyes from aqueous effluents is one of the most significant environmental importance. The aim of the present study was to investigate the potential of applicability of CoFe2O4 nanoparticles loaded on activated carbon (AC) (CA-CoFe2O4) for the removal and adsorption of Chrysoidine in water samples. In this research, nanocomposite (CA-CoFe2O4) was prepared. Then, the properties of sorbent (nanocomposite) are characterized by Energy Dispersive Xray Spectroscopy (EDS), and Scanning Electron Microscope (SEM) techniques. In this study, nanoparticles are dispersed in aqueous media by ultrasonic were to facilitate the dispersion of the sorbent. The CA-CoFe2O4containing the extracted dyes was separated from the sample aqueous by centrifuge. The residual Chrysoidine G concentrations were determined by UV-Vis spectroscopy. The factors affecting such as pH, ultrasonic time, adsorbent mass and initial Chrysoidine G concentration on the Chrysoidine G removal of CA-CoFe2O4 was investigated. The experimental results also showed that the adsorption followed with pseudo second-order kinetics model, and the adsorption behavior was accordance with the Freundlich isotherm model. Also, the adsorption capacity of 28.57 mg/g was achieved by CA-CoFe2O4.