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    A catalyzed method to remove polychlorinated biphenyls from contaminated transformer oil

    , Article Environmental Science and Pollution Research ; 2021 ; 09441344 (ISSN) Maghami, A ; Gholipour Zanjani, N ; Khorasheh, F ; Arjmand, M ; Sharif University of Technology
    Springer Science and Business Media Deutschland GmbH  2021
    The disposal of polychlorinated biphenyls (PCBs) as persistent organic pollutants from the environment has been normally performed by isolation from soil or water because of their biological activity and toxic potential. In the present investigation, catalytic hydrodehalogenation was used to detoxify PCBs-contaminated transformer oil. All reactions were directed on an oil containing 11.09 wt% of PCBs utilizing palladium supported on multi-walled carbon nanotubes (Pd/MWCNTs). The amount of hexa-chlorine homologues reduced considerably from 5.07% to less than 800 ppm utilizing HDC at the atmosphere of argon. Moreover, the amounts of long half-lives and bioaccumulative congener of PCB 153... 

    Hybrid adsorption–photocatalysis properties of quaternary magneto-plasmonic ZnO/MWCNTs nanocomposite for applying synergistic photocatalytic removal and membrane filtration in industrial wastewater treatment

    , Article Journal of Photochemistry and Photobiology A: Chemistry ; Volume 391 , 2020 Irani, E ; Amoli Diva, M ; Sharif University of Technology
    Elsevier B.V  2020
    A new multifunctional filtration membrane was prepared by twofold advantages of conventional polymeric-membrane as the supporting layer and magneto-plasmonic Ag-doped ZnO@Fe3O4/MWCNTs nanocomposite as the functional layer. Poly acrylic acid (PAA)-modified polyamide (PA) discs (PAA-PA) were applied to increase the hydrophilicity of prepared membrane and X-Ray diffraction (XRD) and scanning electron microscopy (SEM) techniques were used for characterization. The grafting yield of PAA in the pores and on the surface of PA was 17 wt.% and weigh difference between PAA-PA membrane before and after modifying with the photocatalyst was 8.7 mg. The amount of photocatalyst loading in the prepared... 

    A continuum constitutive model for mechanical behavior of 5052 resin epoxy containing various percentages of MWCNTs

    , Article Journal of Composite Materials ; Volume 51, Issue 17 , 2017 , Pages 2423-2434 ; 00219983 (ISSN) Hosseini Kordkheili, S. A ; Toozandehjani, H ; Ashouri Choshali, H ; Boroumand Azad, S ; Sharif University of Technology
    SAGE Publications Ltd  2017
    In this article, a continuum-based constitutive model is developed to predict the mechanical behavior of 5052 resin epoxy reinforced by multiwalled carbon nanotubes (MWCNTs) based on experimentally generated data. For this purpose, MWCNTs/epoxy specimens with various percentages of functionalized and nonfunctionalized MWCNTs are prepared. The SEM graphs indicate that functionalization leads to a better bound between epoxy and MWCNTs and a higher level of dispersion. The specimens are then tested under standard ASTM D638-02 a procedure and their true plastic stress–strain curves are extracted. Investigations on experimentally generated data reveal that a wt% dependent equation which is... 

    The effects of multi-walled carbon nanotubes graphitization treated with different atmospheres and electrolyte temperatures on electrochemical hydrogen storage

    , Article Electrochimica Acta ; Volume 55, Issue 16 , June , 2010 , Pages 4700-4705 ; 00134686 (ISSN) Reyhani, A ; Nozad Golikand, A ; Mortazavi, S. Z ; Irannejad, L ; Moshfegh, A. Z ; Sharif University of Technology
    Using multi-walled carbon nanotubes (MWCNTs), the present study focuses on their electrochemical hydrogen storage capacities. The results showed that the hydrogen desorption process is composed of two steps with voltages around -0.75 and -0.15 V. Hydrogen adsorption at -0.15 V took place at temperatures above 30 °C, and the amount of energy required for adsorbing hydrogen was 1.68 eV. The hydrogen storage capacity increased with increasing electrolyte temperature from 30 to 60 °C in both steps. The hydrogen storage capacity of the MWCNTs treated at different atmospheres showed that the decrease in the graphitization of MWCNTs led to the increase in hydrogen adsorption. The results also... 

    Experimental investigation on the thermal performance of ultra-stable kerosene-based MWCNTs and Graphene nanofluids

    , Article International Communications in Heat and Mass Transfer ; Volume 108 , 2019 ; 07351933 (ISSN) Askari, S ; Rashidi, A ; Koolivand, H ; Sharif University of Technology
    Elsevier Ltd  2019
    A simple chemisorption method was used to graft on the surface of MWCNTs and Graphene nanoparticles to prepare stable kerosene-based MWCNTs and Graphene nanofluids. The prepared nanofluids remained stable for more than five months and no sedimentation was observed. Regarding the effect of temperature on thermo-physical properties, it was observed that although increasing nanoparticle concentration led to an increase in the fluid viscosity, it was negligible enough at lower nanoparticle loading. Moreover, adding nanoparticles to the base fluid did not have any noticeable impact on the fluid density which was negligible even at high concentrations. The thermal conductivity improvement was... 

    Investigation of mechanical properties, antibacterial features, and water vapor permeability of polyvinyl alcohol thin films reinforced by glutaraldehyde and multiwalled carbon nanotube

    , Article Polymer Composites ; Vol. 35,Issue. 9 , 2014 , pp. 1736-1743 ; ISSN: 1548-0569 Mohammad Mahdi Dadfar, S ; Kavoosi, G ; Mohammad Ali Dadfar, S ; Sharif University of Technology
    Polyvinyl alcohol (PVA) thin films were reinforced by glutaraldehyde and multiwalled carbon nanotubes (MWCNTs) and then mechanical, water solubility, water swelling, water uptake, water vapor permeability, and antibacterial properties of the films were examined. Cross-linking by glutaraldehyde or incorporation of MWCNT caused a significant increase in tensile strength, decrease in elongation at break, and increase in Young's modulus of the PVA films, while MWCNTs were more effective rather than that of glutaraldehyde. Cross-linking by glutaraldehyde or incorporation of MWCNT caused a significant decrease in water solubility, water swelling and water uptake, with a similar manner.... 

    Hydrogen sensing properties of multi-walled carbon nanotube films sputtered by Pd

    , Article International Journal of Hydrogen Energy ; Volume 35, Issue 9 , 2010 , Pages 4445-4449 ; 03603199 (ISSN) Ghasempour, R ; Mortazavi, S. Z ; Iraji zad, A ; Rahimi, F ; Sharif University of Technology
    Multi-Walled Carbon nanotube (MWCNTs) films were obtained by Thermal Chemical Vapor Deposition method and coated by palladium sputtering process. Raman spectroscopy was used to study alteration in quality of the carbon nanotubes after the sputtering process. Fourier Transform Infra Red (FTIR) spectroscopy showed that hydrogenation process can reduce the C{double bond, long}O to C-O and also produce O-H bond. Furthermore, the electrical resistance measurement for Pd/MWNTs films was performed in a chamber with 1% hydrogen gas in a constant dry air flow. Hydrogen sensing behavior of the films was investigated at 50 °C. Pd/MWCNTs films presented an irreversible gas response to hydrogen in the... 

    A study on the effects of Fex/Niy/MgO(1-x-y) catalysts on the volumetric and electrochemical hydrogen storage of multi-walled carbon nanotubes

    , Article International Journal of Hydrogen Energy ; Volume 35, Issue 1 , 2010 , Pages 231-237 ; 03603199 (ISSN) Reyhani, A ; Mortazavi, S. Z ; Zaker Moshfegh, A ; Nozad Golikand, A ; Sharif University of Technology
    The effects of various ratios of Fe/Ni/MgO and growth temperatures on yield, diameter and quality of multi-walled carbon nanotubes (MWCNTs) were studied. Thermal gravimetric analysis (TGA) confirmed that the MWCNT yield depends on Fe/Ni ratio with the following order; Fe0.5 Ni0.5 > Fe > Fe0.75 Ni0.25 > Fe0.25 Ni0.75 > Ni. The results indicated that there is an optimum temperature (940 °C) for the MWCNT growth both from quality and quantity (yield) aspects as compared to other temperatures. Moreover, the changes on Fe/Ni to MgO ratio for the MWCNT growth revealed that Fe/Ni/MgO with the ratio of 17.5/17.5/65 had the highest quality and surface area as compared to the other ratios. The... 

    Effect of long-chain ionic liquids on the capacitive performance of carbon nanotube-sulfonated polyaniline hydrogels for energy storage applications

    , Article Journal of Physical Chemistry C ; Volume 124, Issue 18 , 2020 , Pages 9810-9821 Hekmat, F ; Shahrokhian, S ; Mirzaei, Y ; Sharif University of Technology
    American Chemical Society  2020
    Imidazolium-based ionic liquids (ILs) have been perceived as a promising candidate for bridging polyaniline (PANI) on well-dispersed carbon nanotubes (CNTs) via formation of IL-stabilized multiwalled carbon nanotubes (MWCNTs) dispersion in which outer walls of CNTs, as well as benzene rings of the aniline monomer and the growing polymer, have been potently effective in such procurement. The sulfonated water-soluble PANI-[C16C1im]Cl-MWCNT nanocomposites (SPANI-IL-MWCNTs) are directly deposited on a graphite-based current collector using a simple and cost-effective electrophoretic deposition (EPD) method. The SPANI-IL-MWCNT electrodes exhibit remarkable electrochemical performance compared to... 

    The effect of various acids treatment on the purification and electrochemical hydrogen storage of multi-walled carbon nanotubes

    , Article Journal of Power Sources ; Volume 183, Issue 2 , 1 September , 2008 , Pages 539-543 ; 03787753 (ISSN) Reyhani, A ; Mortazavi, S. Z ; Nozad Golikand, A ; Moshfegh, A. Z ; Mirershadi, S ; Sharif University of Technology
    Elsevier  2008
    The effects of HCl, HNO3, H2SO4 and HF acids on the purification and the electrochemical hydrogen storage of multi-walled carbon nanotubes (MWCNTs) were studied. The MWCNTs were synthesized on Fe-Ni catalyst by thermal chemical vapor deposition method. The X-ray diffraction and thermal gravimetric analysis results indicated that the MWCNTs purified by HF acid had the highest impurities as compared with the other acids. The N2 adsorption results at 77 K indicated that all the samples were mainly mesoporous and the purified MWCNTs by HF acid had the highest surface area as compared with the other acids. The hydrogen storage capacities of the purified MWCNTs by the following acids were in... 

    H 2 adsorption mechanism in Mg modified multi-walled carbon nanotubes for hydrogen storage

    , Article International Journal of Hydrogen Energy ; Volume 37, Issue 2 , January , 2012 , Pages 1919-1926 ; 03603199 (ISSN) Reyhani, A ; Mortazavi, S. Z ; Mirershadi, S ; Golikand, A. N ; Moshfegh, A. Z ; Sharif University of Technology
    Multi-walled carbon nanotubes (MWCNTs) with diameter of about 50 nm were synthesized using thermal chemical vapor deposition. We have investigated the influence of Mg doping to the MWCNTs on its hydrogen storage property. TEM micrographs showed that Mg was attached to the MWCNTs and discontinuous arrangement of the carbon walls was recognized in the MWCNTs. According to XPS and BET analyses, the surface functional groups and pore size of the Mg-MWCNTs are increased by interactions between the Mg and the MWCNT's outer walls. The electrochemical discharging curves of the MWCNTs and Mg-doped MWCNTs revealed that the hydrogen storage capacity was 363 and 450 mAhg -1, respectively. Volumetric... 

    Enhanced electrochemical hydrogen storage by catalytic Fe-doped multi-walled carbon nanotubes synthesized by thermal chemical vapor deposition

    , Article Journal of Power Sources ; Volume 188, Issue 2 , 2009 , Pages 404-410 ; 03787753 (ISSN) Reyhani, A ; Mortazavi, S.Z ; Moshfegh, A.Z ; Golikand, A.N ; Amiri, M ; Sharif University of Technology
    Hydrogen storage capacities of raw, oxidized, purified and Fe-doped multi-walled carbon nanotubes (MWCNTs) were studied by electrochemical method. Based on transmission electron microscopy and Raman spectroscopic data, thermal oxidation removed defective graphite shells at the outer walls of MWCNTs. The analysis results indicated that the acid treatment dissolved most of the catalysts and opened some tips of the MWCNTs. Thermal gravimetric analysis and differential scanning calorimetry results illustrated that by oxidation and purification of MWCNTs, the weight loss peak shifts toward a higher temperature. N2 adsorption isotherms of the purified and oxidized MWCNTs showed an increase in N2... 

    A selective chemiresistive sensor for the cancer-related volatile organic compound hexanal by using molecularly imprinted polymers and multiwalled carbon nanotubes

    , Article Microchimica Acta ; Volume 186, Issue 3 , 2019 ; 00263672 (ISSN) Janfaza, S ; Banan Nojavani, M ; Nikkhah, M ; Alizadeh, T ; Esfandiar, A ; Ganjali, M. R ; Sharif University of Technology
    Springer-Verlag Wien  2019
    A chemiresistive sensor is described for the lung cancer biomarker hexanal. A composite consisting of molecularly imprinted polymer nanoparticles and multiwalled carbon nanotubes was used in the sensor that is typically operated at a voltage of 4 V and is capable of selectively sensing gaseous hexanal at room temperature. It works in the 10 to 200 ppm concentration range and has a 10 ppm detection limit (at S/N = 3). The sensor signal recovers to a value close to its starting value without the need for heating even after exposure to relatively high levels of hexanal  

    Electrochemical determination of clozapine on MWCNTs/new coccine doped ppy modified GCE: An experimental design approach

    , Article Bioelectrochemistry ; Volume 90 , 2013 , Pages 36-43 ; 15675394 (ISSN) Shahrokhian, S ; Kamalzadeh, Z ; Hamzehloei, A ; Sharif University of Technology
    The electrooxidation of clozapine (CLZ) was studied on the surface of a glassy carbon electrode (GCE) modified with a thin film of multiwalled carbon nanotubes (MWCNTs)/new coccine (NC) doped polypyrrole (PPY) by using linear sweep voltammetry (LSV). The pH of the supporting electrolyte (D), drop size of the cast MWCNTs suspension (E) and accumulation time of CLZ on the surface of modified electrode (F) was considered as effective experimental factors and the oxidation peak current of CLZ was selected as the response. By using factorial-based response-surface methodology, the optimum values of factors were obtained as 5.44, 10 μL and 300 s for D, E and F respectively. Under the optimized...