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polyacrylonitriles
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Manipulation of the electric field of electrospinning system to produce polyacrylonitrile nanofiber yarn
, Article Journal of the Textile Institute ; Volume 98, Issue 3 , 2007 , Pages 237-241 ; 00405000 (ISSN) ; Hosseini, Y ; Hosseini Ravandi , S. A ; Sharif University of Technology
2007
Abstract
Electrospinning is a process that produces nanofiber through the action of an external electric field imposed on a polymer solution or melt. This paper introduces a new system capable of producing continuous uniaxially aligned PAN nanofiber yarn by manipulating the electric field. The manipulation was carried out by employing a negative charged bar in the electric field of conventional electrospinning system, leading to the formation of an electrostatic multipolar field. As a result, the main stream was redirected towards a rotating take up unit, collecting the twisted yarn consisting of uniaxially aligned nanofibers. The yarns were then treated in boiling water under tension and their...
New polysaccharide-g-polyacrylonitrile copolymers: synthesis and thermal characterization [electronic resource]
, Article Polymers for Advanced Technologies ; Volume 14, Issue 7, pages 508–516, July 2003 ; Pourjavadi, Ali ; Sharif University of Technology
Abstract
Various natural and modified polysaccharides (i.e. arabic gum, tragacanth gum, xanthan gum, sodium alginate, chitosan, sodium carboxymethyl cellulose, hydroxyethyl cellulose, methyl cellulose) were modified using ceric-initiated graft polymerization of acrylonitrile under inert atmosphere. Grafting was confirmed using spectral (FT-IR) proofs. The grafting parameters were determined by conventional methods. Thermal characteristics of the homopolymer-free copolymers were studied using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) under nitrogen atmosphere. The major thermal transitions as well as the activation energy of the major decomposition stages were...
Superabsorbent hydrogels from starch-g-PAN: Effect of some reaction variables on swelling behavior
, Article Journal of Polymer Materials ; Volume 20, Issue 1 , 2003 , Pages 113-120 ; 09700838 (ISSN) ; Pourjavadi, A ; Sharif University of Technology
2003
Abstract
Two series of alkali hydrolyzed starch-g-polyacrylonitrile (H-SPAN) superabsorbents were prepared from granular and gelatinized corn starches. The grafting parameters of SPAN copolymers were determined and the polymers were analyzed by FTIR spectroscopy. A combination of three influencing factors (i.e. thermal pre-treatment of the initial starch, presence or absence of oxygen in the stage of ceric-initiated PAN grafting, and neutralization after alkali treatment) on swelling characteristics of the final hydrogel was evaluated in a practical viewpoint. The superabsorbents were discriminated according to their swelling behavior in water and different aqueous salt solutions. The swelling...
Synthesis and superswelling behavior of carboxymethylcellulose-poly(sodium acrylate-co-acrylamide) hydrogel
, Article Journal of Applied Polymer Science ; Volume 108, Issue 2 , 2008 , Pages 1142-1151 ; 00218995 (ISSN) ; Hosseinzadeh, H ; Sharif University of Technology
2008
Abstract
In this paper, attention is paid to synthesis and swelling behavior of a superabsorbent hydrogel based carboxymethylcellulose (CMC) and polyacrylonitrile (PAN). The physical mixture of CMC and PAN was hydrolyzed in NaOH solution to yield hydrogel, CMC-poly(NaAA-co-AAm). During alkaline hydrolysis, the nitrile groups of PAN were completely converted to a mixture of hydrophilic carboxamide and carboxylate groups followed by in situ crosslinking of the grafted PAN chains. A proposed mechanism for hydrogel formation was suggested and the structure of the product was established using FTIR spectroscopy. The reaction variables affecting the swelling capacity of the hydrogel were systematically...
Modified CMC: Part1-optimized synthesis of carboxymethyl cellulose-g-polyacrylonitrile
, Article Iranian Polymer Journal (English Edition) ; Volume 14, Issue 2 , 2005 , Pages 131-138 ; 10261265 (ISSN) ; Pourjavadi, A ; Sadeghi, M ; Sharif University of Technology
2005
Abstract
As the first part of a continued research on conversion of carboxymethyl cellulose-sodium salt (CMC) to useful biopolymer-based materials, large numbers of cyanide functional groups were introduced onto CMC by grafting with polyacrylonitrile (PAN). The graft copolymerization reactions were carried out under nitrogen atmosphere using ceric ammonium nitrate (CAN) as an initiator. Evidence of grafting was obtained by comparing FTIR spectra of CMC and the graft copolymer as well as solubility characteristics of the products. The synthetic conditions were systematically optimized through studying the effective factors including temperature and concentrations of initiator, acrylonitrile monomer,...
Preparation and Characterization of Electrospun Nanofiberous Membranes for Wastewater Treatment
, M.Sc. Thesis Sharif University of Technology ; Bastani, Daruoosh (Supervisor) ; Moosavi, Ali (Supervisor)
Abstract
The aim of the current project is preparation, characterization and microfiltration evaluation of nanofiberous membrane. In order to prepare membranes, the electrospinning method was utilized and polyacrylonitrile and N-N, dimethylformamide (DMF) were used as the polymer and the solvent, respectively. As the nanofiber diameter controls the structure of the membrane and also bead formation reduces the membrane uniformity, at first the effects of four most influential electrospinning parameters, such as solution concentration, applied voltage, floe rate, and the distance between needle tip and the collector, on average fiber diameter and bead area density were investigated via response surface...
Preparation and characterization of PVC/PAN blend ultrafiltration membranes: Effect of PAN concentration and PEG with different molecular weight
, Article Desalination and Water Treatment ; Volume 58 , 2017 , Pages 1-11 ; 19443994 (ISSN) ; Mojtaba Seyedi, S ; Rabiei, H ; Alvandifar, N ; Arya, A ; Sharif University of Technology
Desalination Publications
2017
Abstract
The current study investigates the effect of polyacrylonitrile (PAN) addition on morphology and antifouling properties of poly(vinyl chloride) (PVC) asymmetric flat ultrafiltration (UF) membranes. The membranes are prepared via phase inversion method induced by immersion precipitation at different PVC/PAN blending ratio up to 40 wt% PAN. Also, membranes with blending ratio of PVC/ PAN:70/30, which showed the highest water flux and flux recovery ratio, were used for membrane preparation with 4 wt% of Polyethylene glycol (PEG) addition in four different molecular weight, 600 Da, 1,000 Da, 6,000 Da and 20,000 Da, which was used as pore former and hydrophilic polymeric additive. The performance...
Partially hydrolyzed kappa carrageenan - polyacrylonitrile as a novel biopolymer-based superabsorbent hydrogel: synthesis, characterization, and swelling behaviors
, Article Polymer Engineering and Science ; Volume 46, Issue 12 , 2006 , Pages 1778-1786 ; 00323888 (ISSN) ; Pourjavadi, A ; Sharif University of Technology
2006
Abstract
In this paper, synthesis and swelling behavior of a novel superabsorbent hydrogel based on kappa carrageenan (κC) and polyacrylonitrile (PAN) was investigated. To achieve partially hydrolyzed κC-PAN hydrogel, physical mixture of κC and PAN was hydrolyzed by NaOH solution. During alkaline hydrolysis, the nitrile groups of PAN are converted to a mixture of hydrophilic carboxamide and carboxylate groups follow by in situ crosslinking of the grafted PAN chains. The reaction variables affecting on the swelling capacity of the hydrogel were systematically optimized to achieve a hydrogel with swelling capacity as high as possible. Under the optimized conditions concluded, super swelling hydrogel...
New polysaccharide-g-polyacrylonitrile copolymers: Synthesis and thermal characterization
, Article Polymers for Advanced Technologies ; Volume 14, Issue 7 , 2003 , Pages 508-516 ; 10427147 (ISSN) ; Pourjavadi, A ; Sharif University of Technology
2003
Abstract
Various natural and modified polysaccharides (i.e. arabic gum, tragacanth gum, xanthan gum, sodium alginate, chitosan, sodium carboxymethyl cellulose, hydroxyethyl cellulose, methyl cellulose) were modified using cericinitiated graft polymerization of acrylonitrile under inert atmosphere. Grafting was confirmed using spectral (FT-IR) proofs. The grafting parameters were determined by conventional methods. Thermal characteristics of the homopolymer-free copolymers were studied using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) under nitrogen atmosphere. The major thermal transitions as well as the activation energy of the major decomposition stages were...
Modified CMC. V. synthesis and super-swelling behavior of hydrolyzed CMC-g-PAN hydrogel
, Article Journal of Applied Polymer Science ; Volume 103, Issue 2 , 2007 , Pages 877-883 ; 00218995 (ISSN) ; Zohuriaan Mehr, M. J ; Ghasempoori, S. N ; Hossienzadeh, H ; Sharif University of Technology
2007
Abstract
Polyacrylonitrile (PAN) was grafted onto carboxymethyl cellulose (CMC) sodium salt backbones by using cerie ammonium nitrate (CAN) as an initiator. The graft co-polymer, CMC-g-PAN, was hydrolyzed by NaOH solution to yield hydrogel, H-CMC-g-PAN. The nitrile groups of CMC-g-PAN were completely converted to a mixture of hydrophilic carboxamide and carboxylate groups during alkaline hydrolysis, followed by in situ crosslinking of the grafted PAN chains. The structure of the products was confirmed by FTIR spectroscopy. The synthetic parameters affecting the swelling capacity of the hydrogel (i.e., CMC-g-PAN add-on value, the hydrolysis time and temperature, and concentration of NaOH) were...
Synthesis of an alginate-poly(sodium acrylate-co-acrylamide) superabsorbent hydrogel with low salt sensitivity and high pH sensitivity
, Article Journal of Applied Polymer Science ; Volume 101, Issue 5 , 2006 , Pages 2927-2937 ; 00218995 (ISSN) ; Sharifnia, N ; Hosseinzadeh, H ; Sharif University of Technology
2006
Abstract
This article describes the synthesis and swelling behavior of a superabsorbing hydrogel based on sodium alginate (NaAlg) and polyacrylonitrile (PAN). The physical mixture of NaAlg and PAN was hydrolyzed with a solution of NaOH to yield an alginate-poly(sodium acrylate-co-acrylamide) [Alg-poly(NaAA-co-AAm)] superabsorbent hydrogel. A proposed mechanism for hydrogel formation was suggested, and the structure of the product was established with Fourier transform infrared spectroscopy. The effects of reaction variables were systematically optimized to achieve a hydrogel with a swelling capacity as high as possible. Under the optimized conditions concluded, the maximum capacity of swelling in...
High Saline Water Treatment by the Process of Membrane Distillation Combined with Solar Energy
, M.Sc. Thesis Sharif University of Technology ; Rajabi, Abbas (Supervisor) ; Musavi, Abbas (Supervisor)
Abstract
In this study, membrane distillation process was used for treatment of high salinity waters. The focus of this study is to simulate and build a setup of membrane distillation process. Since the membrane distillation process is based on the driving force of the temperature difference, the required temperature is provided by both the use of heaters and the use of solar energy. To increase the feed temperature by solar energy, a black polymer coating on the main membrane is used. The main membrane used in this process is PVDF polymer and the polymer coated on the surface is the PAN polymer. After simulating and constructing the laboratory setup, the influence of a variety of parameters on the...
Evaluation of the Performance of Polyacrylonitrile Membrane Modified with TiO2@MIL-88A (Fe) Photocatalyst for Humic acid Removal in Photocatalytic Membrane Reactor under Visible Light
, M.Sc. Thesis Sharif University of Technology ; Fotovat, Farzam (Supervisor) ; Musavi, Abbas (Supervisor)
Abstract
Membranes are one of the best water and wastewater treatment methods that could successfully replace other less-effective conventional techniques such as adsorption, coagulation, etc. Moreover, relative to other techniques, the quality of the water produced by membrane separation is very high compared to others. One of the main drawbacks of membrane treatment is fouling of the surface and internal pores of the membranes restricting its widespread application in the industry.In this study, TiO2@MIL-88A (Fe) photocatalyst and polyacrylonitrile membrane were modified with this photocatalyst to remove humic acid under visible light irradiation inside the PMR photocatalytic reactor was...
Coke deposition mechanism on the pores of a commercial Pt-Re/γ- Al2O3 naphtha reforming catalyst
, Article Fuel Processing Technology ; Volume 91, Issue 7 , 2010 , Pages 714-722 ; 03783820 (ISSN) ; Mohammadi, M ; Ghorbanpour, A ; Sharif University of Technology
2010
Abstract
Coke deposition mechanism on a commercial Pt-Re/γ-Al 2O3 naphtha reforming catalyst was studied. A used catalyst that was in industrial reforming operation for 28 months, as well as the fresh catalyst of the unit were characterized using XRD, XRF, and nitrogen adsorption/desorption analyses. Carbon and sulfur contents of the fresh and the used catalysts were determined using Leco combustion analyzer. The pore size distributions (PSD) of the fresh and the used reforming catalysts were determined using BJH and Comparison Plot methods. The Comparison Plot method produced the most reasonable PSDs for the catalysts. Through comparison of the PSDs of the fresh and the used catalysts, it was...
PVDF/PAN blend membrane: preparation, characterization and fouling analysis
, Article Journal of Polymers and the Environment ; 2016 , Pages 1-11 ; 15662543 (ISSN) ; Azimi Yancheshme, A ; Rekaabdar, F ; Hemmati, M ; Tavakolmoghadam, M ; Safekordi, A ; Sharif University of Technology
Springer New York LLC
2016
Abstract
Ultrafiltration membranes were prepared from blend of the poly(vinylidene fluoride) (PVDF) with polyacrylonitrile (PAN) via phase inversion method induced by immersion precipitation. N,N-dimethylacetamide (DMAc) and water were used as solvent and coagulant (non-solvent), respectively. The effect of blending ratio on the morphology and antifouling behavior of the prepared membranes was investigated. The performance of the membranes was evaluated by using cross flow filtration of pure water and buffered bovine serum albumin (BSA) solution as feed. Contact angle measurements indicated that the hydrophilicities of the PVDF/PAN membranes increased by increasing PAN concentration in the casting...
Polyamide/polyacrylonitrile thin film composites as forward osmosis membranes
, Article Journal of Applied Polymer Science ; Volume 133, Issue 42 , 2016 ; 00218995 (ISSN) ; Abbaszadeh, M ; Mousavi, S. A ; Soltanieh, M ; Bakhshi, H ; Sharif University of Technology
John Wiley and Sons Inc
Abstract
Thin film composites (TFCs) as forward osmosis (FO) membranes for seawater desalination application were prepared. For this purpose, polyacrylonitrile (PAN) as a moderately hydrophilic polymer was used to fabricate support membranes via nonsolvent-induced phase inversion. A selective thin polyamide (PA) film was then formed on the top of PAN membranes via interfacial polymerization reaction of m-phenylenediamine and trimesoyl chloride (TMC). The effects of PAN solution concentration, solvent mixture, and coagulation bath temperature on the morphology, water permeability, and FO performance of the membranes and composites were studied. Support membranes based on low PAN concentrations (7 wt...
Synthesis of mesoporous functional hematite nanofibrous photoanodes by electrospinning
, Article Polymers for Advanced Technologies ; Volume 27, Issue 3 , 2016 , Pages 358-365 ; 10427147 (ISSN) ; Latifi, M ; Bagherzadeh, R ; Malekshahi Byranvand, M ; Naseri, N ; Dabirian, A ; Sharif University of Technology
John Wiley and Sons Ltd
Abstract
Iron(III) oxide (hematite, Fe2O3) nanofibers, as visible light-induced photoanode for water oxidation reaction of a water splitting process, were fabricated through electrospinning method followed by calcination treatment. The prepared samples were characterized with scanning electron microscopy, and three-electrode galvanostat/potentiostat for evaluating their photoelectrochemical (PEC) properties. The diameter of the as-spun fibers is about 300nm, and calcinated fibers have diameter less than 110nm with mesoporous structure. Optimized multilayered electrospun α-Fe2O3 nanostructure mats showed photocurrent density of 0.53mA/cm2 under dark and visible illumination conditions at voltage 1.23V...
PVDF/PAN blend membrane: preparation, characterization and fouling analysis
, Article Journal of Polymers and the Environment ; Volume 25, Issue 4 , 2017 , Pages 1348-1358 ; 15662543 (ISSN) ; Yancheshme, A. A ; Rekaabdar, F ; Hemmati, M ; Tavakolmoghadam, M ; Safekordi, A ; Sharif University of Technology
Abstract
Ultrafiltration membranes were prepared from blend of the poly(vinylidene fluoride) (PVDF) with polyacrylonitrile (PAN) via phase inversion method induced by immersion precipitation. N,N-dimethylacetamide (DMAc) and water were used as solvent and coagulant (non-solvent), respectively. The effect of blending ratio on the morphology and antifouling behavior of the prepared membranes was investigated. The performance of the membranes was evaluated by using cross flow filtration of pure water and buffered bovine serum albumin (BSA) solution as feed. Contact angle measurements indicated that the hydrophilicities of the PVDF/PAN membranes increased by increasing PAN concentration in the casting...
A novel magnetic polyacrylonotrile-based palladium core−shell complex: a highly efficient catalyst for synthesis of Diaryl ethers
, Article Journal of Organometallic Chemistry ; Volume 916 , 14 June , 2020 ; Jarahiyan, A ; Eslami, M ; Pourjavadi, A ; Sharif University of Technology
Elsevier B.V
2020
Abstract
The present article describes the synthesis of a new magnetic polyacrylonitrile-based Pd catalyst involving polyacrylonitrile modified via 2-aminopyridine as an efficient support to immobilize Pd nanoparticles. The simple reusability, easy separation and high stability of this Pd complex make it an excellent candidate to generate a C–O bond via Ph-X activation which is a really important subject in achieving biologically active compounds. It is worth to note access to good and high yields as well as broad substrate scope have resulted from superior reactivity of this catalyst complex. Furthermore, the structure of the magnetic polyacrylonitrile-based heterogeneous catalyst was characterized...
Tunable surface plasmon resonance–based remote actuation of bimetallic core-shell nanoparticle-coated Stimuli responsive polymer for switchable chemo-photothermal synergistic cancer therapy
, Article Journal of Pharmaceutical Sciences ; Volume 107, Issue 10 , 2018 , Pages 2618-2627 ; 00223549 (ISSN) ; Sadighi Bonabi, R ; Pourghazi, K ; Hadilou, N ; Sharif University of Technology
Abstract
New dual light/temperature-responsive nanocarriers were synthesized using bimetallic plasmonic Au-Ag and Ag-Au nanoparticles (NPs) as cores of vehicles which subsequently functionalized with an upper critical solubility temperature–based poly acrylamide-co-acrylonitrile using reversible addition-fragmentation chain transfer for spatiotemporally controlled chemo-photothermal synergistic cancer therapy. The bimetallic cores were assigned to sense wavelengths close to the localized surface plasmon resonance of monometallic NP shell to produce heat which not only can increase the surrounding temperature over the upper critical solubility temperature of polymer to open its valves and promote drug...