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    Preparation of polyaniline/graphene coated wearable thermoelectric fabric using ultrasonic-assisted dip-coating method

    , Article Materials for Renewable and Sustainable Energy ; Volume 9, Issue 4 , 2020 Amirabad, R ; Ramazani Saadatabadi, A ; Siadati, M. H ; Sharif University of Technology
    Springer Science and Business Media Deutschland GmbH  2020
    Abstract: The use of thermoelectric fabrics for powering wearable devices is expected to become widespread soon. A thermoelectric fabric was prepared by coating nanocomposite of polyaniline/graphene nanosheets (PANI/GNS) on a fabric. Four samples of the fabric containing different wt% of GNS (0.5, 2.5, 5, and 10) were prepared. To characterize the samples, Fourier transform infrared (FTIR) spectra, attenuated total reflectance-Fourier transform infrared (AT-FTIR) spectra, field-emission scanning electron microscopy (FE-SEM), electrical conductivity and Seebeck coefficient measurements were used. The electrical conductivity increased from 0.0188 to 0.277 S cm−1 (from 0.5 to 10 wt% of the GNS... 

    Impedance analysis of growth and morphology of electropolymerized polypyrrole nanocomposites [electronic resource]

    , Article Journal of New Materials for Electrochemical Systems ; 2014, Volume 17, Number 2 Torabi, M. (Morteza) ; Sadrnezhaad, S. K ; Sharif University of Technology
    Pure polypyrrole (PPy), PPy/Al2O3 and PPy/SiO2 nanocomposites synthesized galvanostatically using different polymerization charges. Electrochemical impedance measurements of pure polypyrrole revealed that the film thickness affected the impedance responses. The characteristic frequencies vs. film thickness that obtained using Cole-Cole plots showed that electrodeposition mechanism changed from 3D to 1D after nuclei overlapping for pure PPy. Analysis of the nanocomposites impedance spectrums revealed no changes during the film growth, i.e. deposition continues 3D even after nuclei overlapping. Scanning electron microscopy (SEM) confirmed the impedance results and showed that the morphology of... 

    Measuring Concentration of Heavy Metals in Waste Water Using Biosensor

    , M.Sc. Thesis Sharif University of Technology Heydarian Dolatabadi, Ehsan (Author) ; Alemzadeh, Iran (Supervisor) ; Kalantarian, Asadollah (Supervisor)
    Wastewater, especially with heavy metal contamination, is a global environmental concern. Numerous techniques have been tested for online controlling and monitoring the concentration of heavy metal ions; yet, there are many challenges in performing these techniques. Biosensor is cheap, easily available, simple, fast, selective, sensitive, and repeatable so it is an excellent alternative for the detection and quantification of hazardous particles in the wastewater. In this study, a Nano biosensor with high detection of copper ions has been fabricated. PEDOT:PSS as a highly conductive polymer is coupled with gold nanoparticles to modify the surface of graphite electrode and results in higher... 

    Synthesis of new electromagnetic nanocomposite based on modified Fe3O4 nanoparticles with enhanced magnetic, conductive, and catalytic properties

    , Article International Journal of Polymeric Materials and Polymeric Biomaterials ; Volume 65, Issue 8 , 2016 , Pages 384-390 ; 00914037 (ISSN) Pourjavadi, A ; Doroudian, M ; Afshar Saveh, Z ; Doulabi, M ; Sharif University of Technology
    Taylor and Francis Inc  2016
    A new method for the fabrication of an electromagnetic nanocomposite based on Fe3O4 and polyaniline (PANI) is offered. The authors focused on improvement of the physical and electromagnetic properties of the nanocomposite using a new synthetic method. Supermagnetic Fe3O4 nanoparticles were synthesized through coprecipitation method. As a chemical modification, the third generation of poly (amidoamine) dendrimer was grafted on the surface of the nanoparticles. PANI was grafted from -NH2 functional groups of dendrimer via in situ polymerization of aniline. Finally, Au nanoparticles were loaded on the nanocomposite and its catalytic activity for reduction reactions was studied  

    Compressive modulus and deformation mechanisms of 3DG foams: Experimental investigation and multiscale modeling

    , Article Nanotechnology ; Volume 32, Issue 48 , 2021 ; 09574484 (ISSN) Mahdavi, S. M ; Adibnazari, S ; Del Monte, F ; Gutiérrez, M. C ; Sharif University of Technology
    IOP Publishing Ltd  2021
    Due to the wide applications of three-dimensional graphene (3DG) foam in bio-sensors, stretchable electronics, and conductive polymer composites, predicting its mechanical behavior is of paramount importance. In this paper, a novel multiscale finite element model is proposed to predict the compressive modulus of 3DG foams with various densities. It considers the effects of pore size and structure and the thickness of graphene walls on 3DG foams' overall behavior. According to the scanning electron microscope images, a unit cell is selected in the microscale step to represent the incidental arrangement of graphene sheets in 3DG foams. After derivation of equivalent elastic constants of the... 

    Thermal synergistic effect in hybrid filler epoxy composites consisting of graphene nanoplatelets and SiC particles

    , Article Thermal Science and Engineering Progress ; Volume 25 , 2021 ; 24519049 (ISSN) Nouri Borujerdi, A ; Kazemi Ranjbar, S ; Sharif University of Technology
    Elsevier Ltd  2021
    The use of hybrid filler is a promising strategy for development of thermally conductive polymer composites. This paper reported the measurement of thermal conductivity of the epoxy composite filled with a hybrid filler of graphene nanoplatelet (GNP) and silicon carbide (SiC) microparticles. For this hybrid filler, the effect of the average size of SiC on composite thermal conductivity was examined. The results showed that the thermal synergistic effect was highly affected by the average size of the SiC. By using a hybrid filler of 11% vol. GNP and 9% vol. 1 µm-size SiC micro-particles thermal conductivity has reached 3.44 W m−1 K−1. This value is 42% higher than the thermal conductivity of... 

    An easy method to modify PEDOT:PSS/perovskite interfaces for solar cells with efficiency exceeding 15%

    , Article RSC Advances ; Volume 6, Issue 70 , 2016 , Pages 65594-65599 ; 20462069 (ISSN) Shahbazi, S ; Tajabadi, F ; Shiu, H. S ; Sedighi, R ; Jokar, E ; Gholipour, S ; Taghavinia, N ; Afshar, S ; Diau, E. W. G ; Sharif University of Technology
    Royal Society of Chemistry  2016
    Herein, we show that surface treatment of PEDOT:PSS films using propionic acid (PA) results in better device performance for the resulting CH3NH3PbI3 perovskite solar cells (PCE > 15%). N2 blow spreading of PA appears critical in enhanced performance. This weak acid treatment leads to no worse roughness, while providing larger perovskite grains  

    Efficient carrier utilization induced by conductive polypyrrole additives in organic-inorganic halide perovskite solar cells

    , Article Solar Energy ; Volume 207 , 2020 , Pages 1300-1307 Zarenezhad, H ; Balkan, T ; Solati, N ; Halali, M ; Askari, M ; Kaya, S ; Sharif University of Technology
    Elsevier Ltd  2020
    The morphology of the perovskite layer, the effective extraction of the charge carriers, and their transport are the main factors determining the power conversion efficiency (PCE) of the perovskite solar cells (PSCs). In this work, we demonstrated that the geometric and electronic structures of the PSCs could be modified by using a conductive polymer additive in the lead (Pb) halide layer prepared by a two-step deposition method. Polypyrrole (PPy) as a conductive polymer is used in the perovskite layers which could increase the PCE of CH3NH3PbI3-xClx mixed-halide PSCs. By adding an optimized amount of PPy, PCE has been raised from 10.4 to 13.2%. PPy acts as a conductive channel facilitating... 

    Design and Fabrication of Conductive Nanofibrous Scaffolds in Nerve Tissue Engineering

    , M.Sc. Thesis Sharif University of Technology Soleymani, Maryam (Author) ; Mashayekhan, Shohreh (Supervisor) ; Ramezani Saadat, Ahmad (Supervisor)
    The nervous system is the most important communication machine in body which regulates the function of other organs. Peripheral nerves in contrary to central nervous system have the potential for regeneration, but regrowth requires proper environmental conditions and supporting growth factors. Tissue engineered scaffolds create a suitable milieu for disconnected axon to regenerate. The aim of this study in the first stage is the fabrication of nanostructured of conductive polymers (graphene and polyaniline) within a bed of gelatin polymer and then conducting some analyses including conductance, degradation rate and tensile test besides morphological analyses of fibers through SEM and... 

    Design and Fabrication of Conductive Polymeric Nanocomposite Scaffolds for Nerve Tissue Engineering

    , Ph.D. Dissertation Sharif University of Technology Baniasadi, Hossein (Author) ; Ramezani Saadat, Ahmad (Supervisor)
    In the current study, design, fabrication, and characterization of a novel conductive nanocomposite scaffold for nerve tissue engineering applications is reported. For this purpose, the highly conductive polyaniline/graphene nanocomposite (PAG) was synthesized via emulsion polymerization, used for fabrication of conductive chitosan/gelatin/PAG scaffolds, and the effect of PAG amount on the various properties of scaffolds were investigated. The synthesized graphene, polyaniline, and PAG were characterized and the obtained results revealed that partially exfoliated graphene nanosheets and highly conductive PAG with a conductivity of about 12 S.cm-1 and 7 S.cm-1, respectively were obtained. The... 

    Design and Fabrication of Nanocamposite Scaffold for Neural Tissue Engineering

    , M.Sc. Thesis Sharif University of Technology Ramezani Farani, Marzieh (Author) ; Ramazani Saadat Abadi , Ahmad (Supervisor) ; Neamati, ZiaratAli (Supervisor)
    Nervous system plays an intricate biological process of man body.Damage of nervous system has serious consequences and is hard to recover, as well as the other parts of the body may not work properly. Many strategies have been used to repair spinal cord injuries in which the main objective is to improve the regeneration of axons and functional recovery. The purpose of this research is introducing neural tissue engineering concepts (e.g. scaffolds, stimulation and etc.) and also design and fabrication suitable for neural tissue engineering. For this purpose the combination of biodegradable polymers (chitosan),conductive polymer (poly-aniline) and carbon nanosheets (graphene) was chosen as the... 

    Synthesis of Silver Based Nanocomposite

    , M.Sc. Thesis Sharif University of Technology Jelvani Esfahani, Samaneh (Author) ; Bagheri, Habib (Supervisor)
    Recently, conductive nanocomposites have found great deals of attentions due to their vast applications in different fields. According to the definition of nanocomposite, the filler component should be in the range of 10-100 nm. In this study, silver nanoparticles was used as filler with 4 nm size and synthesized by microemulsion method that is known as the best approach for fabricating silver nanoparticles with small sizes, narrow size distribution and high stability.
    Copoly (ortho-phenylenediamine/dopamine) was used as matrix component. Ortho-phenylenediamine is one of the conductive polymers that was used less than other conductive polymers such as polyaniline in this research area.... 

    Enhancing seebeck coefficient and electrical conductivity of polyaniline/carbon nanotube–coated thermoelectric fabric

    , Article Journal of Industrial Textiles ; 2021 ; 15280837 (ISSN) Amirabad, R ; Ramazani Saadatabadi, A ; Pourjahanbakhsh, M ; Siadati, M. H ; Sharif University of Technology
    SAGE Publications Ltd  2021
    In this work, flexible thermoelectric fabrics, polyester/yarn fabrics coated with polyaniline/carbon nanotube (PANI/CNT) nanocomposite, were fabricated by sequential processing: (I) polyaniline/carbon nanotube nanocomposites preparation by a one-step in-situ polymerization and (II) dip coating of a mixture solution of CNT-doped PANI on a polyester/yarn fabric. Nanocomposites were synthesized with various CNT content (0.5, 2.5, 5, and 10 wt%) and characterized using different methods. The Seebeck coefficient and electrical conductivity measurements were used to determine their thermoelectric properties. The results revealed significant improvement in both electrical conductivity and the... 

    In pursuit of a replacement for conventional high-density polyethylene tubes in ground source heat pumps from their composites – a comparative study

    , Article Geothermics ; Volume 87 , September , 2020 Narei, H ; Fatehifar, M ; Ghasempour, R ; Noorollahi, Y ; Sharif University of Technology
    Elsevier Ltd  2020
    Ground-source heat pumps, as the most environmentally friendly and energy-efficient air conditioning technology, suffer from a great required length of ground heat exchanger, partly arising from the low thermal conductivity of high-density polyethylene tubes commonly used in ground heat exchangers. In an attempt to find a replacement with an acceptable thermal conductivity for high-density polyethylene tubes, in this study, first, a comprehensive comparative study on fillers commonly used in thermally conductive polymer composites and resulting high-density polyethylene composites was conducted. Then, based on the advantages and disadvantages presented, an appropriate composite was selected... 

    Fabrication of Hybrid Supercapacitors Based on Graphene-Conducting Polymers and Some Metallic Oxides and Sulfides and Investigation of Their Electrochemical Behavior

    , Ph.D. Dissertation Sharif University of Technology Asen, Parvin (Author) ; Shahrokhian, Saeed (Supervisor) ; IrajiZad, Azam (Co-Supervisor)
    In this research, metal oxides and hydroxides with carbon materials and conductive polymers (CPs), as well as transition metal oxysulfide nanostructures (TMOS), hybrid of Tin oxide and sulfie and polyphasphate-reduced graphene oxide (PPO-RGO) have been used as an active electrode materials for supercapacitors. In the first section of thesis, Tiron and graphene oxide (GO) were used as an anionic dopants to increase the capacity and stability of polypyrrole (PPy). In order to increase the capacity of Tiron/PPy/GO nanocomposite, vanadium oxide (V2O5) was used. The Tiron/PPy/GO/V2O5 nanocomposite was deposited on a stainless steel (SS) as a substrate via one-step electrochemical deposition... 

    Investigation on Conductivity and Piezoelectric Effects on Biological Properties of Conductive Nerve Regenerating Scaffolds by Nano Composite of Gelatin/Polyvinyl Fluoride/Graphene

    , M.Sc. Thesis Sharif University of Technology Sahrayi, Hamid Reza (Author) ; Ramazani Saadat Abadi, Ahmad (Supervisor) ; Bakhshandeh Abkenar, Haleh (Supervisor) ; Atyabi, Mohammad (Co-Supervisor)
    Neural system in human body due to limitated cell proliferation requires high care, because the damage causes serious hurts and disables different tissues. Limit regeneration in central neural system can cause different neural diseases including brain exhaustions specially in old people, but the peripheral neural system may have been disabled and intrupt some other tissue beacuase of possible external injuries before aging. So that while some damages like neural fibers severing, some new medical care methods are required. Some of these methods are outograft, allograft and xenograft which implants neural tissues either between other patient's tissues or from somebody else's; however these... 

    Production of Thermoelectric Polymer Fabric and Investigation of Their Properties

    , M.Sc. Thesis Sharif University of Technology Amirabad, Reza (Author) ; Ramazani Saadat Abadi, Ahmad (Supervisor) ; Soltanieh, Mohammad (Supervisor)
    Flexible thermoelectric (TE) fabrics were prepared by dip coating of a mixture solution of water base colloidal geraphen nano sheet(GNS) and carbon nano tube(CNT) and polyaniline (PANI) on polyester fabric. The phase composition and morphology of the TE fabrics were investigated by FTIR-ATR diffraction and feld emission scanning electron microscopy. The TE properties of the PANI/GNS or CNT coated fabrics with different GNS and CNT loadings were measured in the temperature range from 303 to 338 K. As the content of GNS increased from 0.5 to 10 wt% and CNT increased from 0.5 to 20 wt%, the electrical conductivity of the PANI/GNS or CNT coated polyester fabrics increased, while the Seebeck... 

    Preparation and Characterization of Chitosan-Gelatin/Polyanilne-Graphene-CNT Nanocomposite for Neural Tissue Engineering

    , M.Sc. Thesis Sharif University of Technology Aein Jamshid, Mohammad (Author) ; Ramazani Saadatabadi, Ahmad (Supervisor)
    Repairing and regeneration of neural tissues have attracted considerable attention due to its direct effect on the quality of patients’ lives. Recent developments in nanotechnology and tissue engineering have facilitated their comprehensive applications in the treatment of neurological diseases, and several effective ways have been proposed to repair defects in neural tissues. The main objective of the researches in this field is to regulate cellular behavior and tissue progression through the design and development of synthetic extracellular matrices, such as novel biomaterials, that enhance cell culture and tissue regeneration. Natural polymers, such as chitosan and gelatin, are suitable... 

    Preparation and Forming of Nerve Growth Channels from Polymeric Nanocomposite by Solution Extrusion and Studing their Properties

    , M.Sc. Thesis Sharif University of Technology Bayat, Arman (Author) ; Ramazani Saadatabadi, Ahmad (Supervisor)
    The nervous system is the most complex body system and controls other body systems. Damages of the peripheral nervous system will interfere with the functioning of the body. Tissue engineering is used as one of the most effective methods for repairing damaged tissues,by providing 3-dimensional (scaffold) bedding with proper properties, allows the proliferation of Myelin sheath and proliferation of axons. In this study, we used a continuous extrusion process, sodium alginate with different percentages of Polyaniline-Graphene nanoparticle (synthesized by solvent emulsion) was extruded and its properties were determined by FTIR, SEM, MTT, tensile properties, Conductivity, contact angles and... 

    Preparation of Conductive and Semi-Conductive Nanocomposites based on Biocompatible Polymers and Investigation of their Conductive, Mechanical and Electrochemical Properties

    , Ph.D. Dissertation Sharif University of Technology Doroudian, Mohadeseh (Author) ; Pourjavadi, Ali (Supervisor)
    In this study, conductive and semi-conductive nanocomposites based on biocompatible and biodegradable polymers were prepared and their applications in different areas were studied. Considering huge environmental contaminants derived from various industries, biodegradable polymers (synthetic or natural) have attracted more attention in industrial and biological applications. Aside from their eco-friendly properties, there are other advantages such as availability, different chemical structures, uniqe physical properties and capability to improve their characteristics.One way to improve the properties of the biocompatible polymers is fabrication of their composites with different materials to...