Loading...
Search for: polypyrroles
0.007 seconds
Total 56 records

    Investigation of the electrochemical behavior of mesalazine on the surface of a glassy carbon electrode modified with CNT/PPY doped by 1,5-naphthalenedisulfonic acid

    , Article Electroanalysis ; Volume 25, Issue 11 , 2013 , Pages 2481-2491 ; 10400397 (ISSN) Shahrokhian, S ; Hosseini, P ; Kamalzadeh, Z ; Sharif University of Technology
    2013
    Abstract
    A glassy carbon electrode (GCE) was modified with a thin layer of multiwalled carbon nanotubes (MWCNTs) and subsequently, electrochemically deposited poly-pyrrole. The electrochemical behavior of mesalazine was studied on the surface of the modified electrode by applying linear sweep voltammetry (LSV). The electropolymerization process and the electrochemical response toward mesalazine were investigated in the presence of different aromatic anion dopants including, benzenesulfonic acid (BSA), 1,3-benzenedisulfonic acid (1,3-BDSA), 1,5-naphthalenedisulfonic acid (1,5-NDSA) and new coccine (NC). By using 1,5-NDSA as dopant, a significant increase (~418 times) in the peak current of mesalazine... 

    Application of glassy carbon electrode modified with a bilayer of multiwalled carbon nanotube and polypyrrole doped with Nitrazine Yellow for voltammetric determination of naltrexone

    , Article Electroanalysis ; Volume 23, Issue 12 , NOV , 2011 , Pages 2925-2934 ; 10400397 (ISSN) Shahrokhian, S ; Kamalzadeh, Z ; Saberi, R. S ; Sharif University of Technology
    2011
    Abstract
    A new sensitive electrochemical sensor was fabricated based on a layer by layer process. In this process the glassy carbon electrode (GCE) is first coated by a thin film of multiwalled carbon nanotubes (MWCNTs). In the next step, the electropolymerization of pyrrole in the presence of Nitrazine Yellow (NY) as a dopant anion is performed on the surface of the MWCNTs precoated electrode. The electrochemical response characteristics of the modified electrode toward naltrexone (NTX) were studied by means of linear sweep voltammetry (LSV). A remarkable increase (~19 times) was observed in the anodic peak current of NTX on the surface of the modified electrode relative to the bare GCE. The effects... 

    Sensitive electrochemical sensor for determination of methyldopa based on polypyrrole/carbon nanoparticle composite thin film made by in situ electropolymerization

    , Article Electroanalysis ; Volume 23, Issue 9 , 2011 , Pages 2248-2254 ; 10400397 (ISSN) Shahrokhian, S ; Saberi, R. S ; Kamalzadeh, Z ; Sharif University of Technology
    2011
    Abstract
    A composite surface coating is prepared by electropolymerization of a mixture of pyrrole and carbon nanoparticles onto a glassy carbon electrode (GCE). The microscopic structure and morphology of the composite film is characterized by scanning electron microscopy. The modified electrode offers a considerable improvement in voltammetric sensitivity toward methyldopa (m-dopa), compared to the bare and polypyrrole-coated GCEs. A significantly enhanced anodic peak current together with a remarkable increase in sharpness of the cyclic voltammetric (CV) signals are observed for the detection of m-dopa. The effect of experimental parameters, such as scan rate and pH, are investigated by monitoring... 

    Nanostructured ternary composites of PPy/CNT/NiFe2O4 and PPy/CNT/CoFe2O4: Delineating and improving microwave absorption

    , Article Comptes Rendus Chimie ; Volume 21, Issue 9 , 2018 , Pages 862-871 ; 16310748 (ISSN) Ghashghaei, E ; Kheirjou, S ; Asgari, S ; Kazerooni, H ; Sharif University of Technology
    Elsevier Masson SAS  2018
    Abstract
    Two different ternary nanocomposites, PPy/CNT/CoFe2O4 and PPy/CNT/NiFe2O4, were synthesized by in situ polymerization method. The resulting composites were characterized using Fourier transform infrared spectroscopy, transmission electron microscopy, scanning electron microscopy, energy-dispersive spectroscopy, and X-ray diffraction. They were evaluated with the aim of investigating microwave absorption properties. The results showed that the value of microwave reflection decreases as that of prepared nanocomposites increases. This happens with increase in the PPy content and polymerization on the surface. © 2018 Académie des sciences  

    Electrochemical synthesis of polypyrrole in the presence of congo red; application to selective voltammetric determination of dopamine in the presence of ascorbic acid

    , Article Electroanalysis ; Volume 21, Issue 2 , 2009 , Pages 157-164 ; 10400397 (ISSN) Shahrokhian, S ; Zare Mehrjardi, H. R ; Sharif University of Technology
    2009
    Abstract
    The electrosynthesis of polypyrrole (PPy) film has been achieved on glassy carbon electrode (GCE) in aqueous medium of Congo red (CR) by means of cyclic voltammetry (CV). The modified electrode exhibits high electrocatalytic activity toward dopamine (DA) oxidation, with drastic enhancement of the reversibility and peak currents. This modified electrode, due to electrostatic interactions, is capable to mask the response of ascorbic acid (AA) completely and provide an effective method for the detection of minor amounts of dopamine in the presence of high concentrations of AA. The electrochemical response of the film modified electrode is strongly dependent to the switching potential applied in... 

    On-line trace enrichment of phenolic compounds from water using a pyrrole-based polymer as the solid-phase extraction sorbent coupled with high-performance liquid chromatography

    , Article Analytica Chimica Acta ; Volume 513, Issue 2 , 2004 , Pages 445-449 ; 00032670 (ISSN) Bagheri, H ; Mohammadi, A ; Salemi, A ; Sharif University of Technology
    2004
    Abstract
    A pyrrole-based conductive polymer was prepared and applied as new sorbent for on-line solid-phase extraction (SPE) of phenol and chlorophenols from water samples. Polypyrrole (PPy) was synthesized by chemical oxidation of the monomer in non-aqueous solution. The efficiency of this polymer for extraction of phenol and chlorophenols was evaluated using 35 mg of PPy as the sorbent in an on-line SPE system coupled to reversed-phase liquid chromatography with UV detection. The mobile phase were mixture of phosphate buffer-acetonitrile and compounds were eluted by the mobile phase using a six-port switching valve. High volumes of water, up to 160 ml, could be preconcentrated without the loss of... 

    Pyrrole-based conductive polymer as the solid-phase extraction medium for the preconcentration of environmental pollutants in water samples followed by gas chromatography with flame ionization and mass spectrometry detection

    , Article Journal of Chromatography A ; Volume 1015, Issue 1-2 , 2003 , Pages 23-30 ; 00219673 (ISSN) Bagheri, H ; Mohammadi, A ; Sharif University of Technology
    Elsevier  2003
    Abstract
    A pyrrole-based polymer was synthesized and applied as a new sorbent for solid-phase extraction (SPE) of some environmental pollutants from water samples. Polypyrrole (PPy) was synthesized by chemical oxidation of the monomer in nonaqueous solution. SPE of selected phenols, pesticides, and polyaromatic hydrocarbons (PAHs) from aqueous samples were performed using 200mg PPy. The determination was subsequently carried out by gas chromatography-flame ionization detection (GC-FID) and gas chromatography-mass spectrometry (GC-MS). The polymer showed much higher recoveries for aromatic compounds than aliphatics. Preconcentration of sample volumes up 1l led to acceptable recoveries for aromatic and... 

    An Interior Needle Electropolymerized Pyrrole-Based Coating for Headspace Solid-Phase Dynamic Extraction of Chlorophenols

    , M.Sc. Thesis Sharif University of Technology Kamal Abyaneh, Zahra (Author) ; Bagheri, Habib (Supervisor)
    Abstract
    Nowadays, the inside needle capillary adsorption trap (INCAT) technique as a solventless sample preparation approach and alternative extraction method derived from SPME is gaining rising attentions. The INCAT and needle-trap devices are inexpensive, robust, reusable, and are applicable for sampling and analyzing suitable organic compounds from many different sample matrices. Compared to the fragile silica-based SPME fiber, the needle device is nearly impossible to break mechanically. In addition, the extraction medium possesses quite a large extraction phase volume and a powerful preconcentration capability. Similar to SPME, needle-like devices are particularly convenient for automation and... 

    Electrospun composite of polypyrrole-polyamide as a micro-solid phase extraction sorbent

    , Article Analytical and Bioanalytical Chemistry ; 2011 , Pages 1-7 ; 16182642 (ISSN) Bagheri, H ; Aghakhani, A ; Akbari, M ; Ayazi, Z ; Sharif University of Technology
    Abstract
    A micro-solid phase extraction technique was developed using a novel polypyrrole-polyamide nanofiber sheet, fabricated by electrospinning method. The applicability of the new nanofiber sheet was examined as an extracting medium to isolate malathion as a model pesticide from aqueous samples. Solvent desorption was subsequently performed in a microvial, and an aliquot of extractant was injected into gas chromatography-mass spectrometry. Various parameters affecting the electrospinning process including monomer concentration, polyamide content, applied voltage, and electrospinning time were examined. After fabricating the most suitable preparation conditions, influential parameters on the... 

    Microextraction of antidepressant drugs into syringes packed with a nanocomposite consisting of polydopamine, silver nanoparticles and polypyrrole

    , Article Microchimica Acta ; Volume 183, Issue 1 , 2016 , Pages 195-202 ; 00263672 (ISSN) Bagheri, H ; Bani Hashemi, S ; Zandian, F. K ; Sharif University of Technology
    Springer-Verlag Wien 
    Abstract
    We describe a nanocomposite prepared from polydopamine, silver nanoparticles, and polypyrrole (PDA-Ag-PPy) that can be used for the microextraction in packed syringe (MEPS) of tricyclic antidepressants from urine samples. The PDA-Ag-PPy composite was prepared in-situ by the reduction of silver ion - doped PPy during oxidative polymerization of dopamine. The PDA-Ag coatings on the nanoribbon – shaped PPy represent a highly porous, inorganic–organic hybrid nanomaterial that has a wide range of applications. The nanocomposite was characterized by FTIR and scanning electron microscopy. It is shown to be an efficient sorbent for the MEPS of the tricyclic antidepressants amitriptyline, imipramine... 

    Facile preparation of a highly sensitive non-enzymatic glucose sensor based on the composite of Cu(OH)2 nanotubes arrays and conductive polypyrrole

    , Article Microchemical Journal ; Volume 169 , 2021 ; 0026265X (ISSN) Manafi Yeldaghermani, R ; Shahrokhian, S ; Hafezi Kahnamouei, M ; Sharif University of Technology
    Elsevier Inc  2021
    Abstract
    A novel amperometric non-enzymatic glucose sensor is designed by the facile preparation method. It is made by electrodeposition of Cu clusters and converting them to Cu(OH)2 nanotubes (Cu(OH)2NTs) arrays along with thin-film electro-polymerized of spindle-shaped polypyrrole (PPy@Cu(OH)2NTs), which have been doped by using sodium Benzene-1,3-disulfonate as an anion dopant. Various electrochemical methods investigate the electrochemical performance of the modified electrode toward glucose detection. Under the optimized conditions, a significant electrochemical response improvement is observed toward the electro-oxidation of glucose on the PPy@Cu(OH)2NTs electrode's surface relative to the... 

    A polypyrrole-based sorptive microextraction coating for preconcentration of malathion from aquatic media

    , Article Chromatographia ; Volume 74, Issue 9-10 , 2011 , Pages 731-735 ; 00095893 (ISSN) Bagheri, H ; Aghakhani, A ; Ayazi, Z ; Khakinezhad, M ; Sharif University of Technology
    Abstract
    A new micro-solid phase extraction method was developed by combining solid-phase extraction and stir bar sorptive extraction to benefit from the advantages of both techniques. A polypyrrole coating was electrochemically synthesized on the surface of an already used graphite furnace, employed in electro-thermal atomic absorption spectroscopy. The cylindrical geometry of the graphite tube provided a rather huge surface area, suitable for sorptive extraction. The novel sorbent coating was examined as an extracting medium to isolate malathion. Effects of different parameters such as extraction time, salt concentration, sample volume, desorption solvent and time were investigated and optimized.... 

    On the functionality of the polypyrrole nanostructures for surface modification of Co-free Li-rich layered oxide cathode applied in lithium-ion batteries

    , Article Journal of Electroanalytical Chemistry ; Volume 914 , 2022 ; 15726657 (ISSN) Vahdatkhah, P ; Khatiboleslam Sadrnezhaad, S ; Voznyy, O ; Sharif University of Technology
    Elsevier B.V  2022
    Abstract
    Co-free Li-rich manganese nickel oxide (LMNO) materials are emerging as an up-and-coming candidate for high-energy–density cathodes. However, they suffer from severe cycling capacity fading and poor performance rates. Herein, the surface functionalization of an LMNO cathode is designed by polypyrrole (PPy) nanostructure coating. We found that PPy nanoparticles@LMNO cathode exhibits high-capacity retention and enhanced rate capabilities, delivering a discharge capacity as high as 191 mAh g−1, with capacity retention of 96%, after ∼ 200 cycles at a current density of 20 mA g−1. The results indicate that the intercalation and doping pseudocapacitance can be varied depending on the synthesis... 

    Theoretical Study of Adsorption of Organic Pollutants on Polypyrrole with Density Functional Theory (DFT)

    , M.Sc. Thesis Sharif University of Technology Rezaee, Mozafar (Author) ; Rahman Setayesh, Shahrbanoo (Supervisor)
    Abstract
    Phenolic compounds, which are one of the most dangerous compounds for the environment, are present in many effluents of various industries such as petrochemicals and pharmaceuticals, and the need to eliminate these compounds is increasingly felt. In this study, adsorption of three compounds of para-chlorophenol, para-nitrophenol and hydroquinone on polypyrrole adsorbent in the form of neutral, charged, copolymer with polyaniline and phosphorus-doped have been investigated using density functional theory (DFT). Calculations are performed at two levels of b3lyp/6-31+G(d,p) and wb97xd/631+G(d,p) for two different orientations of adsorbate molecules that the correlation-exchange function wb97xd... 

    Simultaneous Analysis of Aliphatic Alcohols Mixtures Using an Electronic Nose Based on Nano/Microstructured Conducting Polypyrrole Film Prepared by Catalytic Electropolymerization on Cu/Au Interdigital Electrodes Using Multivariate Calibration

    , Article IEEE Sensors Journal ; Volume 16, Issue 2 , 2016 , Pages 418-425 ; 1530437X (ISSN) Alizadeh, N ; Babaei, M ; Alizadeh, M. S ; Mani Varnosfaderani, A ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc 
    Abstract
    In this paper, nano/microstructured-conducting polypyrrole has been prepared on Cu/Au interdigital electrode surfaces by using constant potential amperometry technique. The Fe(II) ions were used as catalyst and X = ClO4 -, pTs-, Cl-, TCA-, DS-, DBS- was implemented as anion dopants. The morphologies of the films were investigated by field emission scanning electron microscope. A remarkable dependence was observed between the type of anion dopant and the morphology of polypyrrole (PPy). The sensing behavior of the PPy-X sensor has been studied toward acetone, methanol, ethanol, 1-propanol, 2-propanol, nitromethane, propylamine, pyridine, and gas mixtures of aliphatic alcohols. The responses... 

    Designing a dual-functional epoxy composite system with self-healing/barrier anti-corrosion performance using graphene oxide nano-scale platforms decorated with zinc doped-conductive polypyrrole nanoparticles with great environmental stability and non-toxicity

    , Article Chemical Engineering Journal ; Volume 382 , 15 February , 2020 Mohammadkhani, R ; Ramezanzadeh, M ; Saadatmandi, S ; Ramezanzadeh, B ; Sharif University of Technology
    Elsevier B.V  2020
    Abstract
    Designing a novel epoxy composite system with dual self-healing/barrier anti-corrosion functions using graphene oxide (GO) nano-platforms decorated by polypyrrole (PPy) nanoparticles doped with zinc metal ions is the major objective of this research attempt. GO-PPy-Zn nanoplatform was fabricated via one-pot polymerization of pyrrole monomers on GO and two direct/indirect methods of zinc doping. In order to verify the PPy nanoparticles synthesis on GO sheets several analyses such as UV–visible, XPS, HR-TEM and FE-SEM were performed. The epoxy nanocomposite coatings containing GO-PPy and GO-PPy-Zn nanoplatforms were fabricated and applied on carbon steel. The nanocomposite coatings... 

    Efficient carrier utilization induced by conductive polypyrrole additives in organic-inorganic halide perovskite solar cells

    , Article Solar Energy ; Volume 207 , 2020 , Pages 1300-1307 Zarenezhad, H ; Balkan, T ; Solati, N ; Halali, M ; Askari, M ; Kaya, S ; Sharif University of Technology
    Elsevier Ltd  2020
    Abstract
    The morphology of the perovskite layer, the effective extraction of the charge carriers, and their transport are the main factors determining the power conversion efficiency (PCE) of the perovskite solar cells (PSCs). In this work, we demonstrated that the geometric and electronic structures of the PSCs could be modified by using a conductive polymer additive in the lead (Pb) halide layer prepared by a two-step deposition method. Polypyrrole (PPy) as a conductive polymer is used in the perovskite layers which could increase the PCE of CH3NH3PbI3-xClx mixed-halide PSCs. By adding an optimized amount of PPy, PCE has been raised from 10.4 to 13.2%. PPy acts as a conductive channel facilitating... 

    Electrospinning of Core-shell Nanofibers for Extraction and Determination of Pesticide Residues from Aquatic Media

    , M.Sc. Thesis Sharif University of Technology Rezvani, Omid (Author) ; Bagheri, Habib (Supervisor)
    Abstract
    Porosity and high surface area is a profound concept for creating advance materials. Nanofibers are an important class of nano materials which would be used as novel sorbents because of their high surface to volume ratio as a result of long lengths and nano-to-micro-scale diameters. Electrospining is a simple method for producing fine nanofibers from different meterials such as, polymers, composites and ceramics to prepare highly efficient sorbents. Moreover, electrospining has been developed for fabricating nanofibers with core-shell structures. These structures in compared with conventional fibers have gained higher attentions due to their high aspect ratios and flexiblity in surface... 

    Electrochemical Sensors Based on Electrodes Modified with Composites of Carbon Nanostructures and Polypyrrole; Application to Electrochemical Investigations and Determination of Nifedipine and Tizanidine

    , M.Sc. Thesis Sharif University of Technology Shamloofard, Maryam (Author) ; Shahrokhian, Saeed (Supervisor)
    Abstract
    In the first part, the electropolymerization of pyrrole was performed in the presence of Titan Yellow (TY) as a dopant anion on the surface of the electrode precoated with CNTs. The modified electrode was used to study the voltammetric response of tizanidine (TIZ). A remarkable increase was observed in the anodic peak current of TIZ on the surface of the modified electrode relative to the bare GCE. The surface morphology PPY/CNT/GCE was thoroughly characterized by scanning electron microscopy (SEM) and cyclic voltammetry (CV) techniques. Under the optimized analysis conditions, the modified electrode showed two linear dynamic ranges of 0.01 - 1 μM and 1-10 μM with a detection limit of 3 nM... 

    Solid Phase Dynamic Extraction Based on Polypyrrole Fiber for Determination Trace Amount of Atrazine in Aqueous Samples with GC-MS

    , M.Sc. Thesis Sharif University of Technology Rouhi, Zahra (Author) ; Bagheri, Habib (Supervisor)
    Abstract
    This research is a bout a novel sample prepration procedure that used polypyrrole film into a stainless steel needle as a fiber coating for solid phase dynamic extraction(SPDE) with using a home-made SPDE devise and gas chromatography – mass spectroscopy for the extraction and detectionof Atrazine from the aqueous sample in direct mode of SPDE. Polypyrrole film was directly electrodeposited into the needle in a aqueous sodium dodecyl sulfonate solution with pecial set up in optimom condition of potential, time and concentration of polypyrrole. To enhance the sensitivity of the SPDE , variables affecting adsorption and desorption steps such as temperature,time,PH, flowrate and ionic strength...