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nanofibers
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Synthesis And Preparation of SiBNC Nanofibers
, M.Sc. Thesis Sharif University of Technology ; Faghihi Sani, Mohammad Ali (Supervisor) ; Mahdi Navaz Eghdam, Rouhoulah (Supervisor)
Abstract
Amorphous SiBNC ceramics have been developed as new high temperature materials. They show a high resistance against crystallization, high mechanical properties, low density, and high oxidation stability. Three synthesis methods have been developed for synthesis of SiBNC ceramics namely, Reactive magnetron sputtering, Mechanical alloying plus sintering, and polymer-derived ceramics. In this research among polymeric methods one pot synthesis due to high ceramic yield and high mechanical properties have been chosen. Two major methods for nanofiber preparation are Meltspinning and Electrospinng. It is notable that all of researches for SiBNC Nanofiber preparation has been conducted on...
Electrospun nanofibers: A promising horizon toward the detection and treatment of cancer
, Article Analyst ; Volume 145, Issue 8 , 2020 , Pages 2854-2872 ; Rezaei, Z ; Mahmoudifard, M ; Sharif University of Technology
Royal Society of Chemistry
2020
Abstract
Due to the increase in the number of cancer patients, because of environmental parameters, high stress, low immunity, etc., there is an urgent need to develop cost-effective sensors for early targeted detection of cancerous cells with adequate selectivity and efficiency. Early disease diagnosis is important, as it is necessary to start treatments before disease progression. On the other hand, we need new, more efficient cancer treatment approaches with minimized side effects, more biocompatibility, and easy disposal. Nanobiotechnology is a field that can assist in developing new diagnostic and treatment approaches, specifically in fatal cancers. Herein, a study on the different applications...
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...
Electric and Buckling Instabilities Effects on the Dynamics and Geometry of the Fibers in Electrospinning
, Ph.D. Dissertation Sharif University of Technology ; Iraji Zad, Azam (Supervisor) ; Ejtehadi, Mohammad Reza (Supervisor)
Abstract
Since previous models can not give a complete description for electrospinning electrical instability, using polymer solutions with diifferent properties, the aim of the existing thesis is to propose a new model that covers a range of materials from non-conducting to conducting and from viscous to elastic and also the initial jet’s tension. In addition, since the previous models have used large wave length approxiamtions, using accurate calculations we showed that the new model has better results for small wavelengths of about two times the jet’s radii. To compare the model to experimental results, we designed and made a proper setup to record the electrospinning process for a PEO solution...
Electrospun composite of polypyrrole-polyamide as a micro-solid phase extraction sorbent
, Article Analytical and Bioanalytical Chemistry ; 2011 , Pages 1-7 ; 16182642 (ISSN) ; 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...
Vanadium dioxide-anchored porous carbon nanofibers as a Na+ intercalation pseudocapacitance material for development of flexible and super light electrochemical energy storage systems
, Article Applied Materials Today ; Volume 10 , 2018 , Pages 72-85 ; 23529407 (ISSN) ; Shahrokhian, S ; Sharif University of Technology
Elsevier Ltd
2018
Abstract
The development of a flexible binder free electrode based on 3D vanadium dioxide (VO2) nano-architectures has materialized as an effective strategy for fabrication of advanced wearable, portable, and stretchable electronic devices. However, most of the stretchable energy storage devices based on VO2 suffer from a relatively low operating voltage, high weight, low specific capacitance, and thus low energy density. Here, a novel binder free supercapacitor electrode composed of hierarchical VO2 nanosheet arrays grown on porous carbon nanofibers (VO2@PCNFs) is designed using a simple hydrothermal method followed by annealing treatment. The electrochemical evaluation confirmed that the energy...
Pressure-engineered electrophoretic deposition for gentamicin loading within osteoblast-specific cellulose nanofiber scaffolds
, Article Materials Chemistry and Physics ; Volume 272 , 2021 ; 02540584 (ISSN) ; Panahi, M ; Akhavan, O ; Mansoorianfar, M ; Sharif University of Technology
Elsevier Ltd
2021
Abstract
Multi-component nanocomposite thin films (composed of cellulose nanofiber (CNF), alginate, bioglass nanoparticles (BG NPs) and gentamicin) were prepared by using cathodic electrophoretic deposition (EPD) under different isostatic pressures of 10−2 mbar (LP), atmospheric (AP), and 5 bar (HP). According to thermal gravity analysis, larger amounts of CNF and alginate could be deposited on the surface at the AP condition in comparison with the LP and HP conditions. On the other hand, higher amounts of the BG NPs could be deposited at the LP condition as compared to the other conditions. The drug (gentamicin) loading/releasing of the samples prepared at the HP condition was found to be higher...
Polyaniline-nylon-6 electrospun nanofibers for headspace adsorptive microextraction
, Article Analytica Chimica Acta ; Volume 713 , 2012 , Pages 63-69 ; 00032670 (ISSN) ; Aghakhani, A ; Sharif University of Technology
2012
Abstract
A headspace adsorptive microextraction technique was developed using a novel polyaniline-nylon-6 (PANI-N6) nanofiber sheet, fabricated by electrospinning. The homogeneity and the porosity of the prepared PANI-N6 sheet were studied using the scanning electron microscopy (SEM) and nanofibers diameters were found to be around 200nm. The novel nanofiber sheet was examined as an extracting medium to isolate some selected chlorobenzenes (CBs), as model compounds, from aquatic media. The extracted analytes were desorbed using μL-amounts of solvent and eventually an aliquot of extractant was injected into gas chromatography-mass spectrometry (GC-MS). Various parameters affecting the extraction and...
Synthesis and Characterization of Electrospun Ceramic Nanofibers
, M.Sc. Thesis Sharif University of Technology ; Bagheri, Habib (Supervisor)
Abstract
Electrospinning is a simple and versatile technique for producing polymeric and ceramic nanofibers. The conventional procedure for fabrication of ceramic nanofibers is a combination of sol-gel techniques and electrospinning. The main challenge is the spin polymer nanofiber in fabricate of fibers with diameter from 1 to 100 nm, while their standard deviation are as low as possible. Uniform beads free polyamidenanofibers with lower diameter were fabricated.A 18% w/w of polyamide in formic acid was chosen and the effect of magnetic field, adding magnetic ionic liquid surfactant, auxiliary electrode on the main fiber were investigated. They termsfiber 1 to fiber 5. The mean diameters of 489,...
Effect of TiO2 nanofiber density on organic-inorganic based hybrid solar cells
, Article International Journal of Engineering, Transactions A: Basics ; Vol. 27, issue. 7 , 2014 , p. 1133-1138 ; Kasaeian, A. B ; Nikfarjam, A. R ; Mohammadpour, R ; Sharif University of Technology
Abstract
In this work, a comparative study of hybrid solar cells based on P3HT and TiO2 nanofibers was accomplished. Electrospinning, a low cost production method for large area nanofibrous films, was employed to fabricate the organic-inorganic hybrid solar cells based on poly (3-hexylthiophene) and TiO2 nanofibers. The performance of the hybrid solar cells was analyzed for four density levels of TiO2 nanofibers which resulted in the average power conversion efficiency of about 0.0134% under AM 1.5 simulated illuminations (100 mWcm-2). It is found that the higher densities of TiO2 lead to more interface area and generating exciton, so the power conversion efficiency will be increased till the active...
Nano composite coating based on cellulose nanofibers/carbon nanoparticles: application to voltammetric determination of clonazepam
, Article Journal of Solid State Electrochemistry ; Vol. 19, issue. 1 , 2014 , p. 251-260 ; Balotf, H ; Ghalkhani, M ; Sharif University of Technology
Abstract
A novel electrochemical sensor for clonazepam (CLNP) was fabricated based on immobilizing cellulose nanofibers/carbon nanoparticles (CNFs/CNPs) nanocomposite on glassy carbon electrode (CNFs/CNPs/GCE). The combination of CNFs and CNPs produced a novel kind of structurally uniform and electro-analytically active nanocomposite. The surface morphology of CNFs/CNPs layer deposited onto glassy carbon electrode was characterized by scanning electron microscopy. The results of the voltammetric investigations showed a considerable enhancement in the cathodic peak current of CLNP (up to 60 times) on the surface of CNFs/CNPs/GCE relative to the bare GCE. Under the optimal conditions, the modified...
A study on the plastic properties of unidirectional nanocomposites with interface energy effects
, Article Acta Mechanica ; Volume 224, Issue 4 , 2013 , Pages 789-809 ; 00015970 (ISSN) ; Naghdabadi, R ; Asghari, M ; Sharif University of Technology
2013
Abstract
In this paper, for obtaining an overall size-dependent yield function for nanocomposites containing aligned cylindrical nanofibers, the effects of interface residual stress and interface elasticity are taken into account within a micromechanical framework. Toward this goal, the modified Hill's condition is used, and then, in order to consider effects of the interface residual stress, strains are decomposed into two parts, a part due to the external loadings and the other due to the interface residual stress. Next, utilizing the field fluctuation method, an overall yield function containing effective elastic constants of the material is derived and then simplified for practical loading...
Electrospinning of nanodiamond-modified polysaccharide nanofibers with physico-mechanical properties close to natural skins
, Article Marine Drugs ; Volume 14, Issue 7 , 2016 ; 16603397 (ISSN) ; Mahmoudi, N ; Rezaie Anaran, F ; Simchi, A ; Sharif University of Technology
MDPI AG
Abstract
Electrospinning of biopolymers has gained significant interest for the fabrication of fibrous mats for potential applications in tissue engineering, particularly for wound dressing and skin regeneration. In this study, for the first time, we report successful electrospinning of chitosan-based biopolymers containing bacterial cellulous (33 wt %) and medical grade nanodiamonds (MND) (3 nm; up to 3 wt %). Morphological studies by scanning electron microscopy showed that long and uniform fibers with controllable diameters from 80 to 170 nm were prepared. Introducing diamond nanoparticles facilitated the electrospinning process with a decrease in the size of fibers. Fourier transform infrared...
Effective shear modulus of solids reinforced by randomly oriented-/aligned-elliptic nanofibers in couple stress elasticity
, Article Composites Part B: Engineering ; Volume 117 , 2017 , Pages 150-164 ; 13598368 (ISSN) ; Alemi, B ; Sharif University of Technology
Abstract
Nowadays, by adding a small amount (about 0.5–5% by weight) of a desired nanomaterial to a matrix having certain properties one may design a multifunctional nanocomposites with a remarkably improved macroscopic properties of interest. The capability of conventional continuum theories in treating the problems of embedded ultra-small inhomogeneity with any of its dimensions comparable to the characteristic lengths of the involved constituent phases is questioned, mainly, on the grounds of the accuracy and the size effect. The micromechanical framework based on the Eshelby's ellipsoidal inclusion theory [1] which has been widely used to estimate the overall behavior of composites falls under...
Advanced binder-free electrode based on core–shell nanostructures of mesoporous Co3V2O8-Ni3V2O8 thin layers@porous carbon nanofibers for high-performance and flexible all-solid-state supercapacitors
, Article Chemical Engineering Journal ; Volume 341 , 2018 , Pages 10-26 ; 13858947 (ISSN) ; Shahrokhian, S ; Sharif University of Technology
Elsevier B.V
2018
Abstract
The development of thin layer structures on flexible current collectors has become as an effective strategy for preparing advanced portable and wearable power sources. Herein, a flexible and efficient electrode was fabricated based on electrospun porous carbon nanofibers (PCNFs) substrate with elaborately designed thin layer Co3V2O8-Ni3V2O8 core–shell nanostructures (Co3V2O8-Ni3V2O8 TLs@PCNFs). The resulting free-standing Co3V2O8-Ni3V2O8 TLs@PCNFs composite was used directly as a flexible electrode in three electrode system for supercapacitor studies without the need for utilization of either binder or metal-based current collector. The unique thin layer structure of Co3V2O8-Ni3V2O8...
Synthesis of ethyl cellulose/aluminosilicate zeolite nanofibrous membranes for oil–water separation and oil absorption
, Article Cellulose ; Volume 26, Issue 18 , 2019 , Pages 9787-9801 ; 09690239 (ISSN) ; Jamshidifard, S ; ZabihiSahebi, A ; Abouchenari, A ; Darabi, M ; Irani, M ; Sharif University of Technology
Springer Netherlands
2019
Abstract
ZSM-5 (Seolite Sconoy Mobil) aluminosilicate zeolites synthesized by the hydrothermal method were incorporated into the hydrophobic ethyl cellulose (EC) nanofibrous membrane. The performance of synthesized nanofibers was investigated for a gravity driven oil–water separation. The synthesized ZSM-5 nanozeolites and EC/ZSM-5 composite nanofibers were characterized using XRD, FESEM, XPS, FTIR and AFM analysis. The permeability of EC/ZSM-5 5 wt% for oil in water mixture was in order of n-hexane (5170 ± 60 L/m2 h) > n-heptane (4600 ± 50 L/m2 h) > cyclohexane (4350 ± 35 L/m2 h) > pump oil (3780 ± 28 L/m2 h) > lubricating oil (3200 ± 25 L/m2 h) > motor oil (2980 ± 20 L/m2 h) with a separation...
Different PES nanofibrous membrane parameters effect on the efficacy of immunoassay performance
, Article Polymers for Advanced Technologies ; Volume 30, Issue 8 , 2019 , Pages 1968-1977 ; 10427147 (ISSN) ; Vossoughi, M ; Sharif University of Technology
John Wiley and Sons Ltd
2019
Abstract
The contribution of electrospun nanofibrous membranes (e.NFMs) in the biosensing platforms opens up a new prospect for the invention of faster and more sensitive analytical devices. In this paper, we utilized e.NFM of polyethersulfone (PES) as a solid substrate for the protein immobilization through two different approaches: physical and covalent. Scanning electron microscopy (SEM) and Fourier-transform-infrared (FTIR) tests were performed to study the effect of plasma treatment on protein immobilization efficacy. Moreover, taking advantage of ELISA technique, the influence of different parameters, namely, nanofibers diameter, membrane thickness, plasma treatment time, an incubation time of...
Improving the multi-step fabrication approach of copper nanofiber networks based transparent electrode for achieving superb conductivity and transparency
, Article Materials Research Express ; Volume 6, Issue 9 , 2019 ; 20531591 (ISSN) ; Angizi, S ; Sadrnezhaad, S. K ; Nikzad, M. J ; Sharif University of Technology
Institute of Physics Publishing
2019
Abstract
Transparent Conductive Electrode (TCE), as an essential part of the optoelectronic devices, has become popular owing to its unique properties such as high optical transmittance and conductivity. Among utilized materials for fabrication of TCE, copper nanofibers (NFs)-network have been attracting much attention due to its extraordinary properties such as low sheet resistance, the scalable manufacturing and low-cost fabrication method. However, many challenges exist in the way of multi-step fabrication of network to increase the NFs continuity and consequently, improvement of their electrical conductivity as TCE. Herein, we report a deep investigation of the effective parameters on diameter...
Improving the multi-step fabrication approach of copper nanofiber networks based transparent electrode for achieving superb conductivity and transparency
, Article Materials Research Express ; Volume 6, Issue 9 , 2019 ; 20531591 (ISSN) ; Angizi, S ; Sadrnezhaad, S. K ; Nikzad, M. J ; Sharif University of Technology
Institute of Physics Publishing
2019
Abstract
Transparent Conductive Electrode (TCE), as an essential part of the optoelectronic devices, has become popular owing to its unique properties such as high optical transmittance and conductivity. Among utilized materials for fabrication of TCE, copper nanofibers (NFs)-network have been attracting much attention due to its extraordinary properties such as low sheet resistance, the scalable manufacturing and low-cost fabrication method. However, many challenges exist in the way of multi-step fabrication of network to increase the NFs continuity and consequently, improvement of their electrical conductivity as TCE. Herein, we report a deep investigation of the effective parameters on diameter...
Synthesis and morphology optimization of electrospun SiBNC nanofibers
, Article Ceramics International ; Volume 46, Issue 5 , 2020 , Pages 6052-6059 ; Mehdinavaz Aghdam, R ; Shahedi Asl, M ; Faghihi Sani, M. A ; Sharif University of Technology
Elsevier Ltd
2020
Abstract
SiBNC nanofibers were synthesized through the polymeric route by a one-pot synthesis approach. DMTA (dichloroboryl methyl trichlorosilyl amine) polymer was selected as pre-ceramic for SiBNC, which was shaped into nanofibers by electrospinning. Then, the nanofibers were cured in an inert atmosphere in order to obtain the final ceramic. By changing the curing atmosphere, the compound of final ceramic has been manipulated. In addition, the ceramic yield of DMTA as a preceramic was increased in the nitrogen atmosphere. The effects of applied voltage, solution concentration, and feeding rate on the morphology of final electrospun ceramic nanofibers were also investigated. Final ceramic remains...