Effect of chemically activated natural vermiculite nanosheets on the performance of mixed matrix polyethersulfone membranes

Mahdie Safarpour,Omid Hosseinpour,Amir Reza Fareghi,Alireza Amani-Ghadim 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.123 No.-

In this study, natural raw vermiculite (RVMT) nanosheets, as an accessible and economic mineral, werechemically activated and used to modify polyethersulfone (PES) membranes. In this way, RVMT wasmodified with acid (AVMT) and cetyltrimethyl ammonium bromide (CTAB, OVMT) to increase its hydrophilicfunctional groups and dispersion properties. Various characterization methods, such as XRD andFTIR, verified the successful preparation of AVMT and OVMT. PES polymeric membranes’ properties wereimproved by the utilization of these additives. The fabrication of AVMT and OVMT/PES mixed matrixmembranes with different quantities (0–1 wt.%) was carried out by a non-solvent-induced phase separationprocedure. The asymmetric structure of the membranes was confirmed by SEM images. By modifyingthe matrix of the PES membranes, the porosity of the obtained membranes was improved from 60.50to 84.92 and 85.09% in the presence of AVMT and OVMT, respectively. Furthermore, the flux of the PESmixed matrix membranes containing 0.5 wt.% AVMT and OVMT were enhanced from 201.76 to 315.89and 272.07 L/m2 h with an improved flux recovery ratio of 51.81 and 49.15%, respectively.

A review on two-dimensional metal oxide and metal hydroxide nanosheets for modification of polymeric membranes

Mahdie Safarpour,Samira Arefi Oskoui,Alireza Khataee 한국공업화학회 2020 Journal of Industrial and Engineering Chemistry Vol.82 No.-

Recently, ultrathin two-dimensional (2D) materials, known as nanosheets, have attracted great interestowning to their ultimate structural and desirable physical, chemical, thermal, electrical, and opticalcharacteristics. Various potential applications of 2D nanomaterials have been reported in electronics/optoelectronics, electrocatalysis, batteries, supercapacitors, solar cells, sensors, photocatalysis, and otherenvironmental processes. Modification of polymeric membranes using nanosheets is increasinglyreported in the literature. The incorporation of inorganic nanostructured additives, such as metal oxideand metal hydroxide nanosheets, can impart desired characteristics to the surface and matrix of themembrane and improves itsfiltration performance. This review summarizes the preparation methods ofthe metal oxide and metal hydroxide nanosheets, with a special emphasis on the recent advances in thisfield. The structural and physicochemical properties of the 2D nanosheets have been discussed, and afterthat, the applications of these nanosheets for modification of polymeric membranes are presented with afocus on the membranes used for environmental applications. Finally, the existing challenges and futureperspectives for synthesis and membrane-related applications of 2D metal oxide and metal hydroxidenanosheets are discussed.

Frequency and thermal buckling information of laminated composite doubly curved open nanoshell

Dai, Humin,Safarpour, Hamed Techno-Press 2021 Advances in nano research Vol.10 No.1

In the present computational approach, thermal buckling and frequency characteristics of a doubly curved laminated nanopanel with the aid of Two-Dimensional Generalized Differential Quadrature Method (2D-GDQM) and Nonlocal Strain Gradient Theory (NSGT) are investigated. Additionally, the temperature changes along the thickness direction nonlinearly. The novelty of the current study is in considering the effects of laminated composite and thermal in addition of size effect on frequency, thermal buckling, and dynamic deflections of the laminated nanopanel. The acquired numerical and analytical results are compared by each other to validate the results. The results demonstrate that some geometrical and physical parameters, have noticeable effects on the frequency and pre-thermal buckling behavior of the doubly curved open cylindrical laminated nanopanel. The favorable suggestion of this survey is that for designing the laminated nano-sized structure should pay special attention to size-dependent parameters because nonlocal and length scale parameters have an important role in the static and dynamic behaviors of the laminated nanopanel.

Electrochemical degradation of three reactive dyes using carbon paper cathode modified with carbon nanotubes and their simultaneous determination by partial least square method

Nader Djafarzadeh,Mahdie Safarpour,Alireza Khataee 한국화학공학회 2014 Korean Journal of Chemical Engineering Vol.31 No.5

We investigated the treatment of a mixture of three reactive textile dyes (C. I. Reactive Red 195, C. I. ReactiveYellow 84 and C. I. Reactive Blue 69) by electro-Fenton (EF) process using carbon paper cathode modified with carbonnanotubes (CNTs). To study the degradation of mixture of three dyes, a rapid analytical methodology based on recordingUV-Vis spectra during the EF process and the data treatment using partial least square (PLS) as a multivariate calibrationmethod was developed. The three reactive dyes were quantified simultaneously despite the overlap of their spectra. Central composite design was used in the modeling and optimization of the electrochemical decolorization process. The independent variables for modeling were initial concentration of three dyes, applied current in the electrolysis system,and reaction time. Results indicated that the optimum applied current value was about 400 mA for the EF process. Analysis of variance (ANOVA) showed that predicted responses by CCD match the experimental values logically withthe amount of R2 more than 0.92.

Sonocatalytic performance of Er-doped ZnO for degradation of a textile dye

Khataee, A.,Saadi, S.,Safarpour, M.,Joo, S.W. Elsevier Science 2015 Ultrasonics sonochemistry Vol.27 No.-

Pure and erbium (Er)-doped ZnO samples were synthesized through a sonochemical method and characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV-Vis spectroscopy, and X-ray photoelectron spectroscopy (XPS) analysis. The synthesized samples were used as a catalyst for the sonocatalytic decolorization of Reactive Orange 29 (RO29) as a model organic pollutant. The decolorization efficiency was 63%, 68%, 88%, and 75% for undoped, 2%, 4%, and 6% Er-doped ZnO, respectively. The effect of different experimental parameters including catalyst content, dye concentration and ultrasound power was investigated on the sonocatalytic decolorization of RO29. Among several radical scavengers (i.e. chloride, carbonate and sulfate anions and t-butanol), the chloride anion showed the most inhibitive effect on the sonocatalysis performance. Improvement of the sonocatalytic process by K<SUB>2</SUB>S<SUB>2</SUB>O<SUB>8</SUB> and H<SUB>2</SUB>O<SUB>2</SUB> enhancers was also studied. The reusability of the synthesized sonocatalyst was evaluated in several consecutive runs, and a decline of only 4% was observed in the process performance after five runs. The intermediates produced during the degradation of RO29 were identified by GC-MS analysis.

Vibration analysis of inhomogeneous nonlocal beams via a modified couple stress theory incorporating surface effects

Farzad Ebrahimi,Hamed Safarpour 한국풍공학회 2018 Wind and Structures, An International Journal (WAS Vol.27 No.6

This paper presents a free vibration analysis of size-dependent functionally graded (FG) nanobeams with all surface effects considerations on the basis of modified couple stress theory. The material properties of FG nanobeam are assumed to vary according to power law distribution. Based on the Euler–Bernoulli beam theory, the modeled nanobeam and its equations of motion are derived using Hamilton’s principle. An analytical method is used to discretize the model and the equation of motion. The model is validated by comparing the benchmark results with the obtained results. Results show that the vibration behavior of a nanobeam is significantly influenced by surface density, surface tension and surface elasticity. Also, it is shown that by increasing the beam size, influence of surface effect reduces to zero, and the natural frequency tends to its classical value.

Self-cleaning and mechanical properties of modified white cement with nanostructured TiO2.

Khataee, R,Heydari, V,Moradkhannejhad, L,Safarpour, M,Joo, S W American Scientific Publishers 2013 Journal of Nanoscience and Nanotechnology Vol.13 No.7

<P>In the present study, self-cleaning and mechanical properties of white Portland cement by addition of commercial available TiO2 nanoparticles with the average particle size of 80 nm were investigated. X-ray diffraction (XRD), transmission electron microscopy (TEM) and BET were used to characterize TiO2 nanoparticles. For determination of self-cleaning properties of TiO2-modified white cement, colorimetric tests in decolorization of C.I. Basic Red 46 (BR46) in comparison to unmodified cement samples was applied. The results indicated that with increasing the amount of TiO2 nanoparticles in modified cement, self-cleaning property of the samples increased. The mechanical properties of TiO2-modified and unmodified cement samples, such as time of setting of hydraulic cement, compressive strength of hydraulic cement mortar and flexural strength of hydraulic cement mortar were examined. The results indicated that addition of TiO2 nanoparticles up to maximum replacement level of 1.0% improved compressive and flexural strength and decreased its setting time.</P>

Clinical Significance of Serum Vascular Endothelial Growth Factor and Complement 3a Levels in Patients with Colorectal Cancer in Southern Iran

Mehrabani, Davood,Shamsdin, Seyedeh Azra,Dehghan, Alireza,Safarpour, Alireza Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.22

Background: Colon cancer (CRC) is perhaps the second most common cause of cancer mortality. This study determined the clinical significance of serum vascular endothelial growth factor (VEGF) and serum complement 3a (C3a) levels in patients with CRC in Fars province, southern Iran. Materials and Methods: Between June 2010 and June 2012, 110 patients with CRC of both genders and different age groups were divided into 3 groups. Group A included patients who had just undergone surgery; Group B had undergone chemotherapy after surgery; and Group C had undergone chemotherapy and radiotherapy after surgery. Twenty one healthy subjects with normal colonoscopy were considered as a control group. ELISA was undertaken to determine VEGF and C3a levels before and after treatment measures. Results: The mean age of patients was $53.9{\pm}14.1$ years. Considering VEGF level, a significant decrease was visible after treatment measures in groups A and B, but not Group C. For VEGF level, the difference was not statistically significant between two genders and various age groups before and after treatment. No significant difference was found for VEGF level between patients and normal group before any treatment. Regarding C3a levels in 101 subjects, they significantly decreased after treatment measures. Before and after treatment, the difference was statistically significant between two genders, but was not statistically significant among various age groups. Conclusions: As VEGF and C3a levels were significantly lower in patients after treatment, these may be beneficial markers in assessment of CRC therapy especially in early stages.

Contra-diffusion synthesis of ZIF-8 layer on polyvinylidene fluoride ultrafiltration membranes for improved water purification

Atefeh Karimi,Vahid Vatanpour,Alireza Khataee,Mahdie Safarpour 한국공업화학회 2019 Journal of Industrial and Engineering Chemistry Vol.73 No.-

Contra-diffusion synthesis method was used to create a uniform layer of zeolitic imidazolate framework-8 (ZIF-8) on the porous polyvinylidenefluoride (PVDF) ultrafiltration membranes. SEM, FTIR, EDX, AFMand water contact angle analyses were used to characterize the prepared membranes. The modifiedmembrane with 5 h contra-diffusion synthesis time showed maximum pure waterflux of 134 L/m2 hnearly twice of that of the bare PVDF membrane (65.8 L/m2 h). The water purification performance of theprepared membranes was evaluated using dye removal efficiency and the ZIF-8 modified membranesexhibited better performance for dye removal due of the negatively charged surface.

Yb-doped ZnSe nanoparticles: synthesis, physical properties and photocatalytic activity.

Khataee, A R,Hosseini, M,Hanifehpour, Y,Safarpour, M,Joo, S W American Scientific Publishers 2014 Journal of Nanoscience and Nanotechnology Vol.14 No.9

<P>In this study, Yb-doped ZnSe nanoparticles were synthesized by co-reduction method at 150 degrees C and pH = 12 for 24 h. The obtained materials were characterized by X-ray diffraction (XRD), UV-Vis diffuse reflectance spectroscopy (DRS), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Powder XRD patterns indicated that the Yb(x)Zn(1-x)Se crystals (x = 0.00-0.10) are isostructural with ZnSe. SEM and TEM images confirmed doping of Yb3+ into the lattice of ZnSe nanoparticles. The UV-Vis diffuse reflectance characteristics of the Yb-doped ZnSe samples were quite similar to that of the undoped sample and showed a strong photoabsorption at visible light range. The electrical conductivity of Yb-doped ZnSe nanomaterials was higher than pure ZnSe at room temperature, and increased with temperature. The photocatalytic activity of synthesized nanoparticles was investigated by the degradation of Orange II solution under visible light irradiation. It was observed that the color removal efficiency of Yb-doped ZnSe catalyst was much higher than that of pure ZnSe (26.28 and 77.10% after 120 min of treatment for ZnSe and Yb(0.06)Zn(0.94)Se, respectively). The results demonstrated the good photocatalytic ability of synthesized nanoparticles under visible light. Also, it was revealed that the decolorization efficiency of Orange II over Yb-doped ZnSe increased with increasing Yb loading up to 6 mol% and then decreased.</P>