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Experimental Investigation of a Nnanofibrous Membrane Preparation for Dye Removal from Colored Wastewater
, Ph.D. Dissertation Sharif University of Technology ; Vossoughi, Manouchehr (Supervisor) ; Mahmoodi, Niyaz Mohammad (Supervisor)
Abstract
In this research, an adsorptive affinity membrane has been prepared based on the combination of the nanofiber structure’s intrinsic characteristic in the dye adsorption and its membrane filtration properties. Electrospinning method has been used to prepare chitosan/poly(vinyl alcohol) (PVA) nanofibers. The morphology and properties of the prepared nanofibrous membranes were characterized using Fourier-transform infrared spectroscopy (FT-IR), field-emission scanning electron microscopy (FE-SEM), image processing, atomic force microscopy (AFM), and thermogravimetric analysis (TGA). Also, the major drawback of electrospun nanofibrous membranes (ENMs) is their low mechanical resistance. So,...
Nano-composite Conduits with Piezoelectric Properties and Hydrogel as the Luminal Filler for Regeneration of Peripheral Nerve Traumas
, M.Sc. Thesis Sharif University of Technology ; Ramazani Sadatabadi, Ahmad (Supervisor)
Abstract
This article investigates the production of a novel nerve regeneration scaffold by using biodegradable and biocompatible components. In this research, we have provided different methods like electrospinning and PE hydrogels to fabricate it. Electrospun fibers are made of PLLA and CS/Gel combinations. ZnO nanoparticles were used as the piezoelectric agent. Piezoelectricity plays an important part in the strcture of neurons giving them the ability to transfer electrical messages throughout the body. NPs were completely dispersed in the PLLA solution. ZnO particles could increase produced voltages as the concentration increases. PLLA is biodegradable and provide good mechanical properties....
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...
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....
Effects of chemical, electrochemical, and electrospun deposition of polyaniline coatings on surface of anode electrodes for evaluation of MFCs' performance
, Article Journal of Environmental Chemical Engineering ; Volume 8, Issue 5 , 2020 ; Yaghmaei, S ; Ghaderi, S ; Bayat, A ; Mardanpour, M. M ; Sharif University of Technology
Elsevier Ltd
2020
Abstract
In this research, different coating methods of polyaniline (PANI) on the anode electrodes and their performance in microbial fuel cells (MFCs) were investigated. The performance of systems in a discontinuous state was studied using the high energy content dairy industry wastewater. The phase enrichment assessment was conducted under open circuit potential (OCP) and the performance of MFCs coated with PANI through three methods was evaluated via chemical oxygen demand (COD), polarization, power density, energy coulombic efficiency (ECE), coulombic efficiency (CE), and potential efficiency (PE) values. The results showed the maximum value for the power density of 28Wm-3, CE of 17%, and COD of...
Construction of 3D fibrous PCL scaffolds by coaxial electrospinning for protein delivery
, Article Materials Science and Engineering C ; Volume 113 , 2020 ; Jooybar, E ; Abdekhodaie, M. J ; Alvi, M ; Sharif University of Technology
Elsevier Ltd
2020
Abstract
In this study, a three-dimensional tablet-like porous scaffold, comprising core-shell fibers to host proteins inside the core, was developed. The fabrication method involved the novel combination of coaxial and wet electrospinning in a single setting. Poly (ε-caprolactone) was chosen as the based polymer and bovine serum albumin was used as a model protein. These 3D tablet-like scaffolds exhibited adequate porosity and suitable pore size for cell culture and cell infiltration, in addition to appropriate mechanical properties for cartilage tissue engineering. The effects of different parameters on the behavior of the system have been studied and the 3D scaffold based on the core-shell fiber...
Synthesis of TiO2/ZnO electrospun nanofibers coated-sewage sludge carbon for adsorption of Ni(II), Cu(II), and COD from aqueous solutions and industrial wastewaters
, Article Journal of Dispersion Science and Technology ; Volume 42, Issue 6 , 2021 , Pages 802-812 ; 01932691 (ISSN) ; Maddah, A. S ; Mehrdadi, N ; Bidhendi, G. N ; Baghdadi, M ; Sharif University of Technology
Bellwether Publishing, Ltd
2021
Abstract
The nanofibers prepared by electrospinning process have high potential for the removal of toxic matters from wastewaters. In the present study, the titanium dioxide and titanium dioxide/zinc oxide (TiO2/ZnO) nanofibers prepared by electrospinning technique were coated on the sewage sludge carbon (SSC) surface for adsorption of Ni(II), Cu(II), and COD from aqueous solutions and industrial wastewaters of Iran. The synthesized adsorbents were characterized using XRD, SEM and EDX analysis. The effect of adsorbent type, pH, adsorbent dosage, contact time and initial concentrations of Ni(II), Cu(II) and COD on the adsorption capacity of synthesized SSC/TiO2 and SSC/TiO2/ZnO nanofibrous adsorbents...
Fabrication of one Dimensional Nano-Structured of Titanium Dioxide and their Application in Dye Sensitized Solar Cells
, M.Sc. Thesis Sharif University of Technology ; Iraji Zad, Azam (Supervisor)
Abstract
In this research we focus on study and fabrication of titanium dioxide nanofibers and their application in preparation of dye sensitized solar cell’s photo anode in order to improve optical and electrical properties. Titanium dioxide nanofibers was prepared by electroespinning method. To investigate the effect of nanofiber diameter on optical and electrical properties of photo anode, three different diameter of titanium dioxide nanofibers with diameters of 100-200 nm, 200-300 nm and 500-600 nm was prepared by varying the type or amount of polymer in the electrospinning solution and fixing other conditions of electrospinning process. By use of these structures, paste of pure fibers in form of...
Electrospun Functionalized Silica / Polyvinyl Alcohol Nanofibers for On-Line μ-Solid Phase Extraction of Estrone and Estradiol in Biological Samples
, M.Sc. Thesis Sharif University of Technology ; Bagheri, Habib (Supervisor)
Abstract
A method for determination of estrogens in biological samples was developed. This method was based on high performance liquid chromatography using online micro-solid phase extraction with 25 mg sorbent synthesized by electrospining of silica/PVA nanofibers. Poly (vinyl alcohol) (PVA) is an easily electrospun polymer with unique properties such as biocompatibility, processability, and hydrophilicity. Silica is biocompatible, thermally stable, and comparatively inert. Incorporation of silica with PVA produces hybrids with enhanced thermal and chemical stability in sample media and elution solvents without relinquishing the biocompatibility of PVA. The sufficient numbers of disc sheets were cut...
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....
Design and Fabrication of Nerve Guidance Conduit for Perioheral Nerve Regeneration based on Gelatin/Graphene
, M.Sc. Thesis Sharif University of Technology ; Ramazani Saadatabadi, Ahmad (Supervisor) ; Mashayekhan, Shohreh (Co-Advisor)
Abstract
The the nervous system as a most comlicated body system , plays an important and vital role for the body systems. damage to the peripheral nervous system result in nervous system disorders which claissified to Neuropraxia, Axonotmesis and Neurotmesis based on damage itensity. tissue engineering considered as one of the repairing nervous damage way, which by creating 3D substrat (scaffold) with proper physical structure, increses possibility of adhesion, growth and proliferation of cells to increase regeneration rate of damaged nerve. in this study, a combination of dual-electrospinning and rolling the spun film used to preparate a nerve guidance conduit (NGC) based on gelatin, PCL and...
Surface Modification of Bacterial Cellulose-Reinforced Keratin Nanofibers using Pluronic/Gum Tragacanth Hydrogel Nanoparticles Produced by Concurrent gel Electrospray/Polymer Electrospinning Method
, M.Sc. Thesis Sharif University of Technology ; Simchi, Abdolreza (Supervisor) ; Tamjid, Elnaz (Supervisor)
Abstract
In this work, wool keratin/polyethylene oxide (PEO) nanofibrous scaffolds were fabricated by electrospinning method. Bacterial cellulose nanofibrils (BCNFs) were embedded in the electrospun keratin/PEO nanofibers. Incorporation of BCNFs into the nanofibers enhances their hydrophilicity, mechanical properties and cell viability, adhesion and proliferation. Water contact angle of the nanofibers decreased from 126˚ to 83˚by addition of 1 wt % BCNFs. A thermogelling hydrogel based on carboxylated pluronic (Pl-COOH) and gum tragacanth (GT) was fabricated and polymer conjugation was confirmed by FTIR and H-NMR spectroscopy. Morphological and viscoelastic properties of GT-grafted Pl-COOH hydrogels...
Fabrication of a Multi-Layered Scaffold to Be Used in Dermal Wound Healing
, M.Sc. Thesis Sharif University of Technology ; Shamloo, Amir (Supervisor) ; Asghari, Mohsen (Co-Advisor)
Abstract
Wound healing by engineered scaffolds is a new step in bio-technology and medical studies in recent years. The goal of the current study is to propose a novel structure for a tissue-engineered scaffold to be used in wound healing. Influenced from the multi-layered structure of natural human skin, the fabricated scaffold consists of two layers to maximize similarity with natural skin. This product is comprised of an electrospun layer made of polycaprolactone and polyvinyl alcohol and a hydrogel layer made of chitosan and gelatin. In order to form a porous medium in the hydrogel layer, freeze-gelation was used instead of freeze drying. The evaluation of fabricated scaffolds was performed by...
Fabrication of a Collagen-Based Scaffold for Corneal Regeneration
, M.Sc. Thesis Sharif University of Technology ; Abdekhodaie, Mohammad Jafar (Supervisor)
Abstract
Corneal diseases are one of the most common causes of blindness worldwide. The most common way to treat these diseases is to replace the damaged cornea with the donor cornea by corneal transplant. But limitations such as donor tissue deficiency, the risk of disease transmission and transplant rejection have made treatment of these diseases very difficult. A cornea made by tissue engineering can be used as a suitable alternative because of the limitations mentioned for corneal transplantation with donated tissue. At the same time, similarity of the scaffold to normal corneal tissue, both in terms of matrial and structural properties, is essential for proper repair of this scaffold by cells...
Fabrication of Transparent Electrode by Metallic Nanofibers
, M.Sc. Thesis Sharif University of Technology ; Sadrnezhad, Khatiboleslam (Supervisor)
Abstract
Transparent conductive electrode (TCE) is one of the indispensable constituent of optoelectronic devices, which heretofore various materials such as ITO, graphene, CNT, metal nanowire and nanofiber network have been used to produce them. It should also be assumed that the use of low-cost materials, which has cost-effective production method, is essential for the construction of transparent electrodes. Copper nanofiber network film which is obtained from electrospinning process is a promising candidate among these materials because it has superiorities, such as low sheet resistance, proper flexibility and abundance in ground resources, scalable and cost-effective fabrication method. There are...
Fabrication and Characterization of ZnO Composites Nanofibers by Electrospinning Method for Photocatalytic Application
, Ph.D. Dissertation Sharif University of Technology ; Moshfegh, Ali Reza (Supervisor) ; Pourjavadi, Ali (Co-Advisor)
Abstract
In this research we focus on study and fabrication of ZnO composite nanofibers by electrospinning method for photocatalytic application. The most important challenges in the field of photocatalyst are photocatalytic activity under the visible light and efficiency enhancement. ZnO is a wide band gap semiconductor and it is not active under the visible light. In Iran, we have more than 300 sunny days in a year. Therefore fabrication and application of photocatalytic material with activity under the sun light that contained 40% of visible light is so vital in our country. In the first part of this project, ZnO-CNT nanofibers were fabricated and carbon doped in the crystal lattice of the ZnO....
Experimental Study of Silver Based Nanostructures Biocompatibility for Tissue Engineering
, M.Sc. Thesis Sharif University of Technology ; Vossoughi, Manouchehr (Supervisor) ; Yaghmaei, Soheyla (Supervisor)
Abstract
Acceleration of healing process for crucial wounds has been remained a challenging issue and it is critical to improve treatments against infection during wound healing period. Among various antimicrobial agents, silver components has been extensively since they are resistant against a wide range of bacteria. In this study, we developed electrospun mats composed of Polycaprolactone (PCL) and Polyvinyl alcohol (PVA) loaded with major silver components using co-electrospinnig method. Chitosan- Ag nanoparticles was synthesized using chitosan via heating prior to electrospinning. Various amounts of Silver components including Ag+, Silversulfadiazine (SSD) and Chitosan- Ag NPs were added to PVA...
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...
PVP-PVA-BaTiO3 Composites for Medical Applications
, M.Sc. Thesis Sharif University of Technology ; Frounchi, Masoud (Supervisor)
Abstract
Polyvinyl alcohol and polyvinyl pyrrolidone polymers are among the biocompatible and widely used polymers that are very important in medical science and their composites are used in tissue engineering, bone engineering, etc. Various nanoparticles have been used to improve the properties of these composites. With this knowledge, in this study, to prepare a biocompatible nanocomposite for medical engineering and improve the piezoelectric, mechanical, and electrical properties of these two polymers, different percentages of these polymers were prepared with barium titanate nanoparticles and scanning electron microscopy using infrared spectroscopy tests. Mechanical properties tests,...