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Gamma irradiated electro-conductive polylactic acid/polyaniline nanofibers
, Article Synthetic Metals ; Volume 259 , 2020 ; Frounchi, M ; Dadbin, S ; Sharif University of Technology
Elsevier Ltd
2020
Abstract
In this study, polyaniline nanoparticles (PANI NPs) in emeraldine base (EB) form were prepared by a modified method and characterized by FTIR and UV–vis spectroscopies. The average size of the nanoparticles was 140 nm measured by DLS method. The nanoparticles were embedded into polylactic acid (PLA) nanofibers prepared by electrospinning method. It was found that inclusion of PANI NPs in PLA resulted in reduced diameter of the fibers during the electrospinning process. Also, the surface of nanofibers appeared smooth in FE-SEM images without formation of beads. Improvement in mechanical and electrical properties of PLA/PANI nanofibers over the neat PLA nanofibers implied a good dispersion of...
Step-by-step improvement of mixed-matrix nanofiber membrane with functionalized graphene oxide for desalination via air-gap membrane distillation
, Article Separation and Purification Technology ; Volume 256 , 2021 ; 13835866 (ISSN) ; Karimi Sabet, J ; Abbasi, F ; Moosavian, M. A ; Sharif University of Technology
Elsevier B.V
2021
Abstract
A straightforward three-stage method was applied to fabricate a super-hydrophobic mixed-matrix nanofiber membrane using the electrospinning method for desalination purpose. First, a hydrothermal technique was applied to synthesize a super-hydrophobic nano-sheet, called octadecylamine-reduced graphene oxide (ODA-rGO) with a water contact angle of 162°, which was then added to PVDF-HFP dope solution. After, 0.005 wt% LiCl was added to the dope solution to decrease the mean pore size by increasing solution conductivity. Moreover, some membranes were hot-pressed to improve liquid entry pressure (LEP). Eventually, a top-quality nanofiber membrane was synthesized using 0.1 wt% ODA-rGO and 0.005...
Highly conductive self-electrical stimuli core-shell conduit based on PVDF-chitosan–gelatin filled with in-situ gellan gum as a possible candidate for nerve regeneration: a rheological, electrical, and structural study
, Article Applied Nanoscience (Switzerland) ; Volume 11, Issue 8 , 2021 , Pages 2199-2213 ; 21905509 (ISSN) ; Ramazani Saadatabadi, A ; Sharif University of Technology
Springer Science and Business Media Deutschland GmbH
2021
Abstract
In the context of peripheral nerve injuries treatment, self-electrical stimuli nerve guidance conduit is a promising technique. To fabricate such structures, PVDF-chitosan–gelatin was considered for the outside walls of conduit and gellan gum containing conductive polyaniline-graphene (PAG) nanocomposite particles in the middle. PVDF-chitosan–gelatin nanofibers were prepared using the dual-electrospinning method and highly conductive binary-doped polyaniline-graphene was synthesized by chemical oxidative polymerization in the presence of aniline and sodium dodecyl sulfate. The morphology and chemical structure of nanofibers and PAG were characterized using SEM and FTIR analyses. The...
Gellan gel comprising short PVDF based-nanofibers: The effect of piezoelectric nanofiber on the mechanical and electrical behavior
, Article Materials Today Communications ; Volume 26 , 2021 ; 23524928 (ISSN) ; Ramazani S. A., A ; H-Shirazi, F ; Hassanzadeh Nemati, N ; Sharif University of Technology
Elsevier Ltd
2021
Abstract
Gel-fiber structure with the potential of extracellular matrix (ECM) mimics can be introduced as a suitable candidate for bioengineering applications. In this study, piezoelectric gellan gel-fiber was prepared with incorporating poly(vinylidenefluoride) (PVDF)/glass-flake in the gellan matrix. Glass-flake nanoparticles were modified with silane group, PVDF/glass-flake nanofibers were synthesized and short-strand nanofibers were fabricated using the mechanical homogenizer method. Brunauer–Emmett–Teller (BET), Fourier-transform infrared spectroscopy (FTIR), and Thermogravimetric analysis (TGA) analyses were used for surface modification study, and scanning electron microscopy (SEM),...
In-situ crosslinking of electrospun gelatin-carbodiimide nanofibers: fabrication, characterization, and modeling of solution parameters
, Article Chemical Engineering Communications ; Volume 208, Issue 7 , 2021 , Pages 976-992 ; 00986445 (ISSN) ; Alemzadeh, I ; Vossoughi, M ; Shamloo, A ; Sharif University of Technology
Taylor and Francis Ltd
2021
Abstract
This work has focused on in-situ crosslinking of gelatin (G) to produce electrospun scaffold with improved fiber morphology retention and mechanical properties. As per this approach, we prepared G nanofibers through mixing G, 1-ethyl-3-(3 dimethylaminopropyl) carbodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS) in the new solvent system. Response surface methodology (RSM) was employed to study the influence of solution parameters on fiber diameter. The morphological structure was examined, and the appropriate level of setting to obtain smooth fibers with a favorable diameter was reported. Results revealed using EDC/NHS for in-situ crosslinking improves the mechanical properties...
Synthesis and Characterization of Electrospun N/S Doped ZnO and Investigation of their Applications in Dye Degradation
, M.Sc. Thesis Sharif University of Technology ; Poujavadi, Ali (Supervisor)
Abstract
In this research, the synthesis of the electrospum nano fiber doped zinc oxide and its photocatalyst usage was investigated. The band gap of the zinc oxide in the area of UV leads to deactivation of this material at the visible light. With due the attention to sunny weather in Iran and the fact that about 50 percentage of sunlight is visible light, producing and usage of catalyst materials actived at visible light is economical. Doping is one of the ways of activating ZnO at visible light, so in this research thiourea is used as the source of ZnO doping. The results of the expriments done at visible light and also spectrums of DRS, XPS and XRD prove that the doping is happened. Also, in this...
Preparation and Characterization of Polymeric Nanocomposite Membrane used in Li-Ion Batteries
, M.Sc. Thesis Sharif University of Technology ; Pircheraghi, Gholamreza (Supervisor)
Abstract
In Lithium ion batteries, the separator is membrane that placed between the cathode and the anode is one of critical components. Its primary function is to effectively transport ionic charge carriers between two electrodes as an efficient ionic conductor as well as to prevent the electric contact between them as a good electric insulator. The separator does not involve directly in any cell reactions, but its structure and properties play an important role in determining the battery performance. Commercially available polyolefin separators low cost, good electric resistance, high electrochemical stability, and effectively prevent thermal runaway caused by the electrical short-circuits or...
Experimental Study of Using Cellulosic Compounds in Tissue Engineering
, M.Sc. Thesis Sharif University of Technology ; Vossoughi, Manouchehr (Supervisor) ; Karimi, Afzal (Supervisor) ; Faghihi, Faezeh (Co-Supervisor)
Abstract
Fabrication and characterization of different surface charged cellulose electrospun scaffolds including cellulose acetate, cellulose, carboxymethyl cellulose and quaternary ammonium cationic cellulose for biomedical applications have been reported in this research. We describe preparation of cellulosic nanofibers through the electrospinning following deacetylation cellulose acetate. Moreover, surface modification of electrospun cellulose nanofibers is carried out to obtain carboxymethyl cellulose and quaternized cellulose nanofibers, respectively. At last, the structural, morphological, mechanical, swelling, wettability and the cell culture properties of the scaffolds were analyzed and...
Design and Construction of PCL Nanofiber Scaffold for Bladder Tissue Engineering
, M.Sc. Thesis Sharif University of Technology ; Yaghmaei, Soheyla (Supervisor) ; Mashayekhan, Shohreh (Co-Advisor)
Abstract
In this project, a novel system of bioactive electrospun scaffold for bladder tissue engineering , has been investigated to control in vitro cell differentiation, and utilize in in vivo vascularization and tissue formation. This method doesn’t have custom bioactive scaffolds problems such as, protein instability, technical complexity and, difficulties in accurate kinetics prediction. First of all, protein loaded chitosan nanoparticles based on ionic gelation interaction between chitosan and Sodium tripolyphosphate were prepared. Maximum protein loading efficiency (80% for BSA & 99% for TGF-beta1) in chitosan nanoparticles was obtained at mean diameter of 51nm. Moreover polycaprolactone...
Electrically Conductive Fibers and Films Based on PLA and Nano PANI
, M.Sc. Thesis Sharif University of Technology ; Frounchi, Masoud (Supervisor) ; Dadbin, Susan (Supervisor)
Abstract
Nowadays, the use of processed conductive polymers for conducting matrix polymers, as well as improving other properties for planting in the body, is very common. In this project, the fabrication and identification of electrically conductive films and fibers from biocompatible poly lactic acid and conductive polyAniline polymer in the form of nano-fibers or nanoparticles was intended. These fibers and films have been made in form of a plate or tube then, have been used as biosensors. These polymeric prostheses should be sterilized before planting in human body. Gamma rays are the best sterilization methods and are used at low doses (25 kGy) to sterilize plastic medical supplies. On the other...
Preparation of Healing Pad with PVA/Chitosan/Nano Silice Nanocomposite using Electrospining
, M.Sc. Thesis Sharif University of Technology ; Ramazani Saeedatabad, Ahmad (Supervisor)
Abstract
Electrospinning process has been widely used to produce nanofibers from polymer blends. Poly(vinyl alcohol) (PVA) and chitosan (CS) have numerous biomedical applications such as wound healing and tissue engineering. Nanofibers of CS/PVA have been prepared by many works, however, a complete physicochemical and mechanical characterization as well as cell behavior has not been reported. In this study, Non-toxic, biodegradable, and biocompatible chitosan/poly(vinyl alcohol)(PVA)/nano silica nanofibers were prepared by electrospinning. The properties of the nanofibers at various blend ratios were investigated by differential scanning calorimetry (DSC), Fourier transform infrared (FTIR)...
Development of plasma and/or chemically induced graft co-polymerized electrospun poly(vinylidene fluoride) membranes for solute separation
, Article Separation and Purification Technology ; Volume 108 , 2013 , Pages 196-204 ; 13835866 (ISSN) ; Rana, D ; Matsuura, T ; Tabe, S ; Feng, C ; Sharif University of Technology
2013
Abstract
Nanofiber membranes were fabricated by electrospinning poly(vinylidene fluoride). The electrospun nanofiber membranes were further modified by grafting of acrylic acid (AA) and methacrylic acid (MAA) over the surfaces of the membranes. Plasma AA graft was attempted only, and the results indicated the partial membrane pore filling with grafted AA. For MAA grafting, chemically induced polymerization using benzoyl peroxide and hydrogen peroxide was attempted. The combination of plasma and chemically induced MAA graft polymerization was also attempted. The membranes were characterized by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and static contact angle (SCA)...
Computational-based approach for predicting porosity of electrospun nanofiber mats using response surface methodology and artificial neural network methods
, Article Journal of Macromolecular Science, Part B: Physics ; Volume 54, Issue 11 , 2015 , Pages 1404-1425 ; 00222348 (ISSN) ; Khodaparast Haghi, A ; Kasaei, S ; Hasanzadeh, M ; Sharif University of Technology
Taylor and Francis Inc
2015
Abstract
Comparative studies between response surface methodology (RSM) and artificial neural network (ANN) methods to find the effects of electrospinning parameters on the porosity of nanofiber mats is described. The four important electrospinning parameters studied included solution concentration (wt.%), applied voltage (kV), spinning distance (cm) and volume flow rate (mL/h). It was found that the applied voltage and solution concentration are the two critical parameters affecting the porosity of the nanofiber mats. The two approaches were compared for their modeling and optimization capabilities with the modeling capability of RSM showing superiority over ANN, having comparatively lower values of...
Preparation and characterization of starch-based composite films reinforced by cellulose nanofibers
, Article International Journal of Biological Macromolecules ; Volume 116 , 2018 , Pages 272-280 ; 01418130 (ISSN) ; Keley, M ; Biazar, E ; Sharif University of Technology
Elsevier B.V
2018
Abstract
The current study deals with the preparation and characterization of polysaccharide-based biocomposite films acquired by the incorporation of cellulose nanofiber within glycerol plasticized matrix formed by starch. The application of starch-based films is limited due to highly hydrophilic nature and poor mechanical properties. These problems are solved by forming a nanocomposite of thermoplastic starch (TPS) as matrix and cellulose nanofiber (CNF) as reinforcement. CNF is successfully prepared from short henequen fibers which consist of almost 60% cellulose by a chemo-mechanical process. TPS/CNF composite films are prepared by the polymer solution casting method, and their characterizations...
Conductive nanofiber scaffold for bone tissue engineering
, Article 24th Iranian Conference on Biomedical Engineering and 2017 2nd International Iranian Conference on Biomedical Engineering, ICBME 2017, 30 November 2017 through 1 December 2017 ; 2018 ; 9781538636091 (ISBN) ; Mashayekhan, S ; Abbaszadeh, H. A ; Ansarizadeh, M ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2018
Abstract
In order to fabricate nanofiber scaffold for bone tissue engineering, electrospinning technique was employed. This technique produces nanofiberous scaffold supporting cell adhesion, migration, and proliferation. Here, we developed a novel conductive scaffold from poly-caprolactone, gelatin, and poly aniline/graphene nanoparticles. In this study, co-electrospinning was utilized to fabricate composite electrospun scaffold. The effect of polyaniline/graphene (PAG) nanoparticles on the mechanical properties and electrical conductivity of this hybrid scaffold was investigated. The result showed that PAG nanoparticles enbance both mechanical properties and electrical conductivity of the scaffolds....
Evaluation of cellular attachment and proliferation on different surface charged functional cellulose electrospun nanofibers
, Article Carbohydrate Polymers ; Volume 207 , 2019 , Pages 796-805 ; 01448617 (ISSN) ; Karimi, A ; Gandomi Ravandi, S ; Vossoughi, M ; Khafaji, M ; Joghataei, M. T ; Faghihi, F ; Sharif University of Technology
Elsevier Ltd
2019
Abstract
Fabrication and characterization of different surface charged cellulose electrospun scaffolds including cellulose acetate (CA), cellulose, carboxymethyl cellulose (CMC) and quaternary ammonium cationic cellulose (QACC) for biomedical applications have been reported in this research. Several instrumental techniques were employed to characterize the nanofibers. MTT assay and cell attachment studies were also carried out to determine the cytocompatibility, viability and proliferation of the scaffolds. Fabricated CA, cellulose, CMC and QACC nanofibers had 100–600 nm diameter, −9, −1.75, −12.8, + 22 mV surface potential, 2.5, 4.2, 7.2, 7 MPa tensile strength, 122, 320, 515, 482 MPa Young modules,...
Interface effects on the electromagnetic radiation emanating from an embedded piezoelectric nano-fiber incident upon by SH-waves
, Article Wave Motion ; Volume 94 , April , 2020 ; Shodja, H. M ; Sharif University of Technology
Elsevier B.V
2020
Abstract
The multiphysics process of the electromagnetic (EM) radiation induced from an embedded nanofiber scatterer subjected to SH-waves is of interest. By discarding the commonly employed electroquasistatic approximation, the fully-coupled elastodynamics and Maxwell's equations have been solved simultaneously within the mathematical framework of piezoelectric surface elasticity theory. Certain subtleties regarding the introduced interface characteristic lengths that make the examination of the size effect on the EM radiated power, scattering cross section, fundamental resonance frequency, and distribution of the magnetic field possible will be discussed. The obtained results can be helpful for...
Gellan gel comprising short PVDF based-nanofibers: the effect of piezoelectric nanofiber on the mechanical and electrical behavior
, Article Materials Today Communications ; 2020 ; Ramazani Saadat Abadi, A ; Shirazi, F. H ; Hassanzadeh Nemati, N ; Sharif University of Technology
Elsevier Ltd
2020
Abstract
Gel-fiber structure with the potential of extracellular matrix (ECM) mimics can be introduced as a suitable candidate for bioengineering applications. In this study, piezoelectric gellan gel-fiber was prepared with incorporating poly(vinylidenefluoride) (PVDF)/glass-flake in the gellan matrix. Glass-flake nanoparticles were modified with silane group, PVDF/glass-flake nanofibers were synthesized and short-strand nanofibers were fabricated using the mechanical homogenizer method. Brunauer–Emmett–Teller (BET), Fourier-transform infrared spectroscopy (FTIR), and Thermogravimetric analysis (TGA) analyses were used for surface modification study, and scanning electron microscopy (SEM),...
An electroconductive, thermosensitive, and injectable chitosan/pluronic/gold-decorated cellulose nanofiber hydrogel as an efficient carrier for regeneration of cardiac tissue
, Article Materials ; Volume 15, Issue 15 , 2022 ; 19961944 (ISSN) ; Maleki Jirsaraei, N ; Simchi, A ; Mohandes, F ; Emami, Z ; Fassina, L ; Naro, F ; Conti, B ; Barbagallo, F ; Sharif University of Technology
MDPI
2022
Abstract
Myocardial infarction is a major cause of death worldwide and remains a social and healthcare burden. Injectable hydrogels with the ability to locally deliver drugs or cells to the damaged area can revolutionize the treatment of heart diseases. Herein, we formulate a thermo-responsive and injectable hydrogel based on conjugated chitosan/poloxamers for cardiac repair. To tailor the mechanical properties and electrical signal transmission, gold nanoparticles (AuNPs) with an average diameter of 50 nm were physically bonded to oxidized bacterial nanocellulose fibers (OBC) and added to the thermosensitive hydrogel at the ratio of 1% w/v. The prepared hydrogels have a porous structure with open...
Electrospun decyl-3-methylimidazolium mono bromate/polyamide nanofibers as solid-phase microextraction coating
, Article Journal of Chromatography A ; Volume 1516 , 2017 , Pages 35-41 ; 00219673 (ISSN) ; Rastegar, S ; Najarzadegan, H ; Ehteshami, S ; Sharif University of Technology
Abstract
In the current study, electrospun-based ionic liquid (IL) doped polyamide (PA) nanofibers were prepared and used as the coating material of solid phase microextration device in the fiber geometry. Addition of IL, decyl-3-methylimidazolium mono bromate, increased the conductivity of the PA solution facilitating the electrospining process. The scanning electron microscopy images of decyl-3-methylimidazolium mono bromated/polyamide nanofibers showed the decreased diameter of the nanofibers in the range of 35–160 nm compared to the PA nanofiber. The factors affecting the structure of nanofibers (e.g. ratio of decyl-3-methylimidazolium mono bromate to PA, coating time and applied voltage) were...