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triazines
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Magnetic nanocomposite of cross-linked Mmelamine groups decorated with large amounts of gold NPs: reduction of nitro compounds and Suzuki–Miyaura coupling reactions in aqueous media
, Article ChemistrySelect ; Volume 3, Issue 10 , March , 2018 , Pages 2716-2722 ; 23656549 (ISSN) ; Keshavarzi, N ; Matloubi Moghaddam, F ; Hosseini, S. H ; Sharif University of Technology
Wiley-Blackwell
2018
Abstract
A magnetic nanocomposite was prepared based on magnetic Fe3O4 nanoparticles entrapped into a cross-linked nitrogen rich polymer which has high loading capacity for immobilization of gold nanoparticles. The synthesized catalyst was characterized using various methods including Atomic absorption spectroscopy (AAS), Transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FT-IR), Energy-dispersive X-ray spectroscopy (EDX), Thermogravimetric analysis (TGA), scanning electron microscope (SEM), Brunauer–Emmett–Teller (BET), VSM and X-ray diffraction (XRD) techniques. The catalyst was proven to be highly efficient for reduction of nitroarenes as well as Suzuki–Miyaura...
New mononuclear manganese(II) complexes with 2,4,6-tris(2-pyridyl)-1,3,5- triazine (tptz) - Selective catalyst in UHP oxidation of sulfides
, Article Polyhedron ; Volume 34, Issue 1 , February , 2012 , Pages 202-209 ; 02775387 (ISSN) ; Hołyńska, M ; Shamkhali, A. N ; Amini, M ; Kazemi, S. H ; Zaynalpoor, S ; Mohamadi, R ; Bagherzadeh, M ; Lis, T ; Sharif University of Technology
2012
Abstract
A new manganese complex of the formula [Mn(tptz)(OH 2) 3](CF 3SO 3) 2·EtOH, (1, where tptz = (2,4,6-tris(2-pyridyl)-1,3,5-triazine) is presented, exhibiting an excellent catalytic activity and selectivity in oxidation of various sulfides to the corresponding sulfoxides with UHP (urea hydrogen peroxide) as oxidant under air at room temperature. A modified preparation procedure produces another new manganese complex of the formula [Mn(tptz)(CH 3COO)(OH 2) 2](CF 3SO 3)·3H 2O (2). X-ray structures of both Mn(II) complexes, properties (elemental analysis, electrochemistry, EPR, IR, Raman, and UV-Vis spectra), as well as DFT studies results are reported
A stable nitrogen-rich zinc-based metal organic framework to investigate the structural similarity effect on the sorption efficiency of nitrogen-containing compounds
, Article Microchemical Journal ; Volume 170 , 2021 ; 0026265X (ISSN) ; Naderi, M ; Bagheri, H ; Sharif University of Technology
Elsevier Inc
2021
Abstract
A stable porous zinc-based metal organic framework (MOF) containing nitrogen-rich bis-tetrazolate ligand was synthesized to study the role of similar structures concerning both extractive phase and the desired solutes to achieve greater sorption efficiency. With implementing a dispersive micro-solid phase extraction (d-µ-SPE) methodology, the sorption capability and influencing structural parameters i.e., porosity, surface area and interactions types were investigated for the synthesized zinc-bis-tetrazolate (ZnBT) MOF and compared with some synthesized sorbents such as MIL-101, MIL-101-NH2, cadmium naphthalene dicarboxylic acid dimethyl formamide [Cd(NDC)(DMF)], polyaniline and LiChrolut®...
Electrospinning of Core-shell Nanofibers for Extraction and Determination of Pesticide Residues from Aquatic Media
, M.Sc. Thesis Sharif University of Technology ; 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...
Polybutylene Terephethalate-based Magnetic Nanofibers for Micro-solid phase Extraction of Triazines from Aquatic Media
, M.Sc. Thesis Sharif University of Technology ; Bagheri, Habib (Supervisor)
Abstract
Porosity and high surface area is a profound concept for creating advance materials. Nanofibers are an important class of nanomaterials with high surface to volume ratio as a result of long lengths and nano-to-micro-scale diameters. Electrospinning is a simple method for producing nanofibers from different polymers and composites and prepare highly efficient sorbents. Polymeric nanocomposites are claimed to exhibit markedly improved mechanical, magnetic, thermal and electrical properties. Magnetic iron oxide nanoparticles have gained great attentions due to their low toxicity, stability and biocompatibility and have been extensively used to induce magnetic property to the desired sorbents....
The Interaction Study of Thio-Organophosphate Pesticides with Colloidal Silver Nanoparticles for Colorimetric Sensing Applications
, M.Sc. Thesis Sharif University of Technology ; Hormozi-Nezhad, Mohammad Reza (Supervisor)
Abstract
Pesticides are broadly applied in croplands, glasshouses, and orchards in order to increase agricultural products and their quality. Among the variety of pesticides, organophosphorus pesticides (OPs), possessing high insecticidal activity, acute toxicity and relatively short environmental persistence, have been widely used for pest control in agriculture. However, this effect might lead to adverse health impacts or death for mammals and humans. Thus, even at trace levels, it is of great importance to develop a simple, sensitive, inexpensive and real-time detection method for monitoring the levels of pesticides in the environment, foodstuffs and biological samples. The integration of metallic...
Preparation of Nitrogen Rich Magnetic Nanocomposite for Immobilization of Transition Metals and Investigation of their Catalytic Activity in Organic Reactions
, Ph.D. Dissertation Sharif University of Technology ; Pourjavadi, Ali (Supervisor) ; Matloubi, Firouz (Supervisor)
Abstract
In this thesis, heterogeneous magnetic catalysts immobilize have been designed and synthesized in a triazine polymer support. Triazine polymeric support increases the amount of nitrogen due to their high levels of nitrogen, which in turn reduces the amount of catalyst consumed and reduces metal waste and increases catalyst activate. Melamine and TCT from the triazine family are used because of the ability to form hydrogen bonds, chelate with metals, and the interaction of π-π as an appropriate ligand for stabilizing metals on substrates. In this thesis, various nitrogen-rich polymers based on triazines in the presence of magnetic nanoparticles coated with silica and their compositions with...
Immersed solvent microextraction and gas chromatography-mass spectrometric detection of s-triazine herbicides in aquatic media
, Article Analytica Chimica Acta ; Volume 537, Issue 1-2 , 2005 , Pages 81-87 ; 00032670 (ISSN) ; Khalilian, F ; Sharif University of Technology
Elsevier
2005
Abstract
An immersed solvent microextraction (SME) method was successfully developed for the trace enrichment of s-triazine herbicides from aquatic media. A microdrop of butyl acetate was applied as the extraction solvent. After extraction, the microdrop was introduced directly into a gas chromatography-mass spectrometry (GC-MS) injection port. Some important extraction parameters such as type of solvent, extraction time, stirring rate, and temperature were investigated and optimized. The highest possible microdrop volume of 3 μl, a sampling temperature of 60°C, and use of butyl acetate are major parameters to obtain high enrichment factors. The enrichment factor and linearity was studied by...
Membrane protected conductive polymer as micro-SPE device for the determination of triazine herbicides in aquatic media
, Article Journal of Separation Science ; Volume 33, Issue 8 , 2010 , Pages 1132-1138 ; 16159306 (ISSN) ; Khalilian, F ; Naderi, M ; Babanezhad, E ; Sharif University of Technology
Abstract
A micro-SPE technique was developed by fabricating a rather small package including a polypropylene membrane shield containing the appropriate sorbent. The package was used for the extraction of some triazine herbicides from aqueous samples. Solvent desorption was subsequently performed in a microvial and an aliquot of extractant was injected into GC-MS. Various sorbents including aniline-ortho-phenylene diamine copolymer, newly synthesized, polypyrrole, multiwall carbon nanotube, C18 and charcoal were examined as extracting media. Among them, conductive polymers exhibited better performance. Influential parameters including extraction and desorption time, desorption solvent and the ionic...
Immobilization of nickel ions onto the magnetic nanocomposite based on cross-linked melamine groups: effective heterogeneous catalyst for N-arylation of arylboronic acids
, Article Applied Organometallic Chemistry ; Volume 32, Issue 2 , February , 2018 ; 02682605 (ISSN) ; Keshavarzi, N ; Matloubi Moghaddam, F ; Hosseini, S. H ; Sharif University of Technology
John Wiley and Sons Ltd
2018
Abstract
A new magnetic heterogeneous catalyst was synthesized by immobilization of nickel ions onto a cross-linked polymeric nanocomposite composed of cyanuric chloride, ethylenediamine and functionalized magnetic nanoparticles. The resulting nitrogen rich support was capable of adsorbing large amounts of nickel ions (1.20 mmol g−1). The synthesized catalyst was characterized using AAS, TEM, FT-IR, EDX, TGA, SEM, BET and XRD techniques. The performance of the prepared catalyst was investigated in the C-N coupling of arylamines with aryl boronic acids. The reaction was carried out under a mild condition and good to moderate to good yields of products was obtained using only 5.0 mol% of the catalyst....
Use of second-order calibration for residue screening of some triazines in the presence of coeluting interferences by gas chromatography-selected ion mass spectrometry
, Article Analytica Chimica Acta ; Volume 537, Issue 1-2 , 2005 , Pages 89-100 ; 00032670 (ISSN) ; Vosough, M ; Sharif University of Technology
Elsevier
2005
Abstract
The quantities of residues of some triazines such as prometon, propazine, atrazine and simazine in complex matrices of apple samples were determined, using gas chromatography-selected ion mass (GC-SIM) spectrometry. Generalized rank annihilation method (GRAM) as a second-order calibration technique was used for screening, resolving and finally determining the amounts of the residues. Before the GRAM analysis, different steps of data preprocessing such as background correction, de-skewing and standardization for rank alignment was used for every target analyte. The de-skewing and rank alignment algorithms were used for bilinearity and trilinearity corrections, respectively. The two data...
Multiresidue determination of pesticides from aquatic media using polyaniline nanowires network as highly efficient sorbent for microextraction in packed syringe
, Article Analytica Chimica Acta ; Volume 740 , 2012 , Pages 43-49 ; 00032670 (ISSN) ; Alipour, N ; Ayazi, Z ; Sharif University of Technology
Abstract
A simple, rapid and sensitive method based on microextraction in packed syringe (MEPS), in combination with gas chromatography-mass spectrometry (GC-MS) was developed. Polyaniline (PANI) nanowires network was synthesized and used as sorbent of MEPS for the multiresidue determination of selected analytes from triazine, organochlrorine and organophosphorous pesticides in aqueous samples. The PANI nanowires network was prepared using soft template technique and its characterization was studied by scanning electron microscopy (SEM). The presence of micelles in this methodology showed to be an important parameter in shaping the growing polymer. Hexadecyltrimethylammonium bromide (HTAB) was used...
A flow injection μ-solid phase extraction system based on electrospun polyaniline nanocomposite
, Article Journal of Chromatography A ; Volume 1433 , 2016 , Pages 34-40 ; 00219673 (ISSN) ; Khanipour, P ; Roostaie, A ; Sharif University of Technology
Elsevier
Abstract
In this study, a fast and sensitive flow injection μ-solid phase extraction (FI-μ-SPE) technique based on an electrospun polyaniline (PANI) nanocomposite in conjunction with gas chromatography-mass spectrometry (GC-MS) was developed. The PANI-based nanocomposite was synthesized by electrospinning of a solution containing polyvinyl alcohol (PVA)/PANI. The majority of PVA template was subsequently removed from the whole PVA/PANI nanofibers blend by exposing the electrospun nanocomposite to hot water. The homogeneity, porosity and characterization of the electrospun nanofibers were investigated by the scanning electron microscopy (SEM) and Fourier transform infrared (FT-IR) spectroscopy. Due to...
A single–step synthesized supehydrophobic melamine formaldehyde foam for trace determination of volatile organic pollutants
, Article Journal of Chromatography A ; Volume 1525 , 2017 , Pages 10-16 ; 00219673 (ISSN) ; Zeinali, S ; Baktash, M. Y ; Sharif University of Technology
Abstract
Superhydrophobic materials have attracted many attentions in recent years while their application in sample preparation remained almost intact. In this project, a rough surface of melamine formaldehyde foam was silanized by chemical deposition of trichloromethylsilane to form a highly porous and superhydrophobic material, presumably a suitable medium for extracting non–polar compounds such as benzene and its methyl derivatives. The prepared sorbent was packed in a needle for the headspace needle–trap microextraction of benzene, toluene, ethylbenzene and xylenes (BTEX). Major parameters associated with the extraction/desorption processes were considered for optimization. Under the optimized...
Implementing a superhydrophobic substrate in immersed solvent–supported microextraction as a novel strategy for determination of organic pollutants in water samples
, Article Ecotoxicology and Environmental Safety ; Volume 163 , 2018 , Pages 104-110 ; 01476513 (ISSN) ; Asem Yousefi, A ; Bagheri, H ; Sharif University of Technology
Academic Press
2018
Abstract
In this research, a new approach for extraction and determination of polycyclic aromatic hydrocarbons from sea and rain water samples was developed by implementing a superhydrophobic substrate and consuming the least amount of solvent. This version of solvent–supported microextraction enabled us to perform the procedure in the immersion mode with the slightest troubles arising from water leakage into the gas chromatography. The superhydrophobic property leads to the fixation of extracting solvent on the substrate surface during water sampling. To prepare a superhydrophobic substrate, a piece of melamine foam was coated by tannic acid and silica nanoparticles using methyltrimethoxysilane and...
Development of Microextraction Methods
for the Trace Determination of Organic Compounds in Biological and Environmental Media
,
Ph.D. Dissertation
Sharif University of Technology
;
Bagheri, Habib
(Supervisor)
Abstract
The approach of this thesis is to develop and simplify robust microextraction techniques and apply these developed methods to real samples and complex matrices. Firstly, a modified solvent microextraction with back extraction method (SME/BE) combined with high performance liquid chromatography and fluorescence detection (HPLC-FD) was developed for the determination of citalopram in human plasma. Extraction process was performed in a home-made total glass vial without using a teflon ring, usually employed in SME/BE. The evaluation results demonstrated that the calibration curve showed linearity in the range of 1.0–130.0 ng/mL which covers therapeutic window and even lower amounts which is...
Magnetic Field Assistedand Flow Injection μ-Solid Pahse Extraction Techniques
, M.Sc. Thesis Sharif University of Technology ; Bagheri, Habib (Supervisor)
Abstract
The main goal of this thesis was to develop μ-solid extraction techniques using electrspun nanofibers under the influence of magnetic field along with flow injection system. The thesis is divided into two sections:The first chapter deals with the use of magnetic field for improving μ-solid phase extraction efficiencies. After preparing the magnetic-based electrospun nanofibers (PBt/MNPs), sufficient numbers of disc from the prepared electrospun composite mat were cut and used as packing materials in a cartridge. The prepared system was coupled on-line to liquid chromatography for microextraction of selected drugs of furosemide, naproxene, diclofenac and clobetasol propionate. The homogeneity...
Polypyrrole nanowires network for convenient and highly efficient microextraction in packed syringe
, Article Analytical Methods ; Volume 3, Issue 11 , 2011 , Pages 2630-2636 ; 17599660 (ISSN) ; Ayazi, Z ; Sharif University of Technology
Abstract
A novel method based on microextraction in packed syringe (MEPS), as a sample preparation technique in combination with gas chromatography-mass spectrometry (GC-MS) was developed using a polypyrrole (PPy) nanowires network as the extracting medium. The PPy nanowires network was prepared using a soft template technique and its characterization was studied by scanning electron microscopy (SEM). The use of micelles in this methodology has an important role in the shape of the growing polymer. The pyrrole monomer was introduced into cetyltrimethylammonium bromide (CTAB) micelles and this has led to the formation of nanowires with diameters ranging from 30 to 60 nm. The bulk PPy prepared without...
A flow injection μ-solid phase extraction system based on electrospun polyaniline nanocomposite
, Article Journal of Chromatography A ; Volume 1433 , February , 2016 , Pages 34–40 ; 00219673 (ISSN) ; Khanipour, P ; Roostaie, A ; Sharif University of Technology
Abstract
In this study, a fast and sensitive flow injection μ-solid phase extraction (FI-μ-SPE) technique based on an electrospun polyaniline (PANI) nanocomposite in conjunction with gas chromatography-mass spectrometry (GC-MS) was developed. The PANI-based nanocomposite was synthesized by electrospinning of a solution containing polyvinyl alcohol (PVA)/PANI. The majority of PVA template was subsequently removed from the whole PVA/PANI nanofibers blend by exposing the electrospun nanocomposite to hot water. The homogeneity, porosity and characterization of the electrospun nanofibers were investigated by the scanning electron microscopy (SEM) and Fourier transform infrared (FT-IR) spectroscopy. Due to...
Toward a comprehensive microextraction/determination unit: A chip silicon rubber polyaniline-based system and its direct coupling with gas chromatography and mass spectrometry
, Article Journal of Separation Science ; Volume 39, Issue 21 , 2016 , Pages 4227-4233 ; 16159306 (ISSN) ; Allahdadlalouni, M ; Zamani, C ; Sharif University of Technology
Wiley-VCH Verlag
2016
Abstract
An inexpensive silicon rubber-based chip was constructed by fabricating a triangle-shaped microcanal with a 135 μm width and 234 μm depth by laser ablation technique. The fabricated groove was sealed by a thin glass cover while two pieces of stainless-steel tubing were connected to each side of the canal. Then, a thin polyaniline film was synthesized on the walls of the canal by chemical oxidation using a syringe pump to deliver the relevant reagents. The microfluidic system was eventually connected to a gas chromatography-mass spectrometry. To evaluate the capability of the constructed microfluidic system, it was implemented to the analysis of submilliliter volumes of environmental samples...