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    Development of electrophoretically deposited hydroxyapatite coatings on anodized nanotubular TiO2 structures: Corrosion and sintering temperature

    , Article Applied Surface Science ; Vol. 301 , May , 2014 , pp. 250-257 ; ISSN: 01694332 Goudarzi, M ; Batmanghelich, F ; Afshar, A ; Dolati, A ; Mortazavi, G ; Sharif University of Technology
    Abstract
    Hydroxyapatite (HA) coatings in and onto anodized TiO2 nanotube arrays were presented and prepared by electrophoretic deposition technique (EPD). Coatings were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). EPD proved to be an innovative and versatile technique to coat HA on and into nanotubular structures of TiO2 with enhanced adhesion between nanotubes and HA particles provided by mechanical interlocking. After EPD of HA on TiO2 layer, samples were sintered at 400 °C, 600 °C and 800 °C for 2 h in an Ar atmosphere. Effect of EPD processing parameters on thickness of the deposits and rate of deposition was elucidated for HA coatings on the nanotubular TiO2... 

    Electronic structure and morphological study of BaTiO 3 film grown by pulsed-laser deposition

    , Article Materials Letters ; Volume 72 , April , 2012 , Pages 107-109 ; 0167577X (ISSN) Ahadi, K ; Mahdavi, S. M ; Nemati, A ; Tabesh, M ; Ranjbar, M ; Sharif University of Technology
    Abstract
    The morphological characteristics and electronic structure of the BaTiO 3 films grown by pulsed-laser deposition technique have been investigated. AFM and FE-SEM images reveal columnar growth characteristic of these films. Utilizing spectrophotometer, optical band gap of the films were reckoned to be about 3.76 eV. Both dα/dE and PL vs. E plots reveal numerous luminance states in the gap. Despite the presence of many luminance faults in the gap, cations manage to preserve their electronic states  

    Surface modifications of titanium implants by multilayer bioactive coatings with drug delivery potential: antimicrobial, biological, and drug release studies

    , Article JOM ; Volume 68, Issue 4 , 2016 , Pages 1100-1108 ; 10474838 (ISSN) Ordikhani, F ; Petrova Zustiak, S ; Simchi, A ; Sharif University of Technology
    Abstract
    Recent strategies to locally deliver antimicrobial agents to combat implant-associated infections—one of the most common complications in orthopedic surgery—are gaining interest. However, achieving a controlled release profile over a desired time frame remains a challenge. In this study, we present an innovative multifactorial approach to combat infections which comprises a multilayer chitosan/bioactive glass/vancomycin nanocomposite coating with an osteoblastic potential and a drug delivery capacity. The bioactive drug-eluting coating was prepared on the surface of titanium foils by a multistep electrophoretic deposition technique. The adopted deposition strategy allowed for a high... 

    Facile synthesis of CuO@PbS core/shell nanowire arrays

    , Article Materials Letters ; Volume 193 , 2017 , Pages 259-262 ; 0167577X (ISSN) Farshidi, H ; Youzbashi, A. A ; Heidari Saani, M ; Rashidi, A ; Kazemzadeh, A ; Kiani, F ; Sharif University of Technology
    Abstract
    Nanowire arrays of copper oxide were first grown vertically using simple and cost effective thermal oxidation method on a copper foil. Subsequently, in order to deposit and grow PbS nanocyrstalline thin films on CuO NWs by utilizing the chemical bath deposition technique, these arrays were immersed as the substrate in the reaction solution consisting of Pb(NO3)2, (NH2)2CS and NaOH. The final products were characterized in detail by which the formation of uniform, unique arrays of CuO@PbS core–shell NWs was confirmed. Due to the nature of methods employed in synthesis of this hetero structure, the tuning of core and shell size and consequently properties of the novel structure is easily... 

    Photovoltaic performance improvement in vacuum-assisted meniscus printed triple-cation mixed-halide perovskite films by surfactant engineering

    , Article ACS Applied Energy Materials ; Volume 2, Issue 9 , 2019 , Pages 6209-6217 ; 25740962 (ISSN) Parvazian, E ; Abdollah Zadeh, A ; Dehghani, M ; Taghavinia, N ; Sharif University of Technology
    American Chemical Society  2019
    Abstract
    Scalable coating methods have recently emerged as practical alternative deposition techniques to the conventional spin-coating despite their lower yielding power conversion efficiencies (PCEs). The most important barrier acting against the use of scalable deposition methods to get a highly absorbing (>95%) film with controlled morphology in the high crystallinity of perovskite particles is the impossibility of antisolvent dripping during the deposition. Here, we demonstrate the positive role of both the surfactant-engineering and the vacuum-annealing (<100 Pa) process in improving the device performance to overcome this limit. A detailed optimization of the vacuum-assisted meniscus printing... 

    Hydrophobic octadecylamine-functionalized graphene/TiO2 hybrid coating for corrosion protection of copper bipolar plates in simulated proton exchange membrane fuel cell environment

    , Article International Journal of Hydrogen Energy ; Volume 45, Issue 30 , 2020 , Pages 15380-15389 Sadeghian, Z ; Hadidi, M. R ; Salehzadeh, D ; Nemati, A ; Sharif University of Technology
    Elsevier Ltd  2020
    Abstract
    In the present work, G-TiO2 and G-ODA-TiO2 hybrids were prepared by concurrent surface functionalization and reducing of graphene oxide (GO) using octadecylamine (ODA). The G-TiO2 and G-ODA-TiO2 powders were deposited on the copper surface by electrophoretic deposition (EPD) technique. The wettability of coatings revealed the preferable hydrophobic characteristic of G-ODA-TiO2 compared to G-TiO2 and bare copper with water contact angles of 130°, 101°, and 87°, respectively. The anti-corrosion performance of specimens in a 0.5 M H2SO4 solution was appraised by the potentiodynamic polarization (Tafel analysis), which clearly showed that G-TiO2 and G-ODA-TiO2 coatings can act as a great barrier... 

    Effect of pH and carbon nanotube content on the corrosion behavior of electrophoretically deposited chitosan-hydroxyapatite-carbon nanotube composite coatings

    , Article Ceramics International ; Volume 39, Issue 5 , July , 2013 , Pages 5393-5402 ; 02728842 (ISSN) Batmanghelich, F ; Ghorbani, M ; Sharif University of Technology
    2013
    Abstract
    In the first stage, chitosan (CH)-hydroxyapatite (HA)-multiwalled carbon nanotube (MWCNT) composite coatings were synthesized by electrophoretic deposition technique (EPD) on 316L stainless steel substrates at different levels of pH and characterized by X-ray diffraction (XRD), Raman spectroscopy, FTIR and field emission scanning electron microscopy (FESEM). A smooth distribution of HA and MWCNT particles in a chitosan matrix with strong interfacial bonding was obtained. In the next stage, effects of pH and MWCNT content of the suspension on the corrosion behavior and deposition mechanism were studied. Potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) curves... 

    Effect of chemical substitution on the morphology and optical properties of Bi1-xCaxFeO3 films grown by pulsed-laser deposition

    , Article Journal of Materials Science: Materials in Electronics ; Volume 24, Issue 1 , 2013 , Pages 248-252 ; 09574522 (ISSN) Ahadi, K ; Mahdavi, S. M ; Nemati, A ; Sharif University of Technology
    2013
    Abstract
    The morphological characteristics as well the optical properties of Ca-doped BiFeO3 films grown by pulsed-laser deposition technique have been investigated. AFM images revealed that calcium has a radical effect on the surface features of BiFeO3 films. By utilizing spectrophotometer, transmission behaviour of the films was investigated. Local IV characteristics of the films disclosed about three orders of magnitude enhancement concerning electrical conductivity through Ca doping. X-ray photoelectron spectroscopy results revealed that Ca can reduce the valence state of iron in the compound  

    Conductor-insulator transition and electronic structure of Ca-doped BiFeO 3 films

    , Article Materials Letters ; Volume 83 , 2012 , Pages 124-126 ; 0167577X (ISSN) Ahadi, K ; Nemati, A ; Mahdavi, S. M ; Sharif University of Technology
    Elsevier  2012
    Abstract
    The electronic conductor-insulator transition in Ca-doped BiFeO 3 films grown by pulsed-laser deposition technique has been investigated. Nature of the transition is resolved to be Mott type through the control of band-filling. Calcium resolved to have colossal effect on enhancing the electrical conductivity of BiFeO 3, but it did not affect band gap of the mother phase perceptibly. UV-visible study yielded band gap of 2.72-2.81 eV (at 300 K) for different concentrations of calcium. Both UV-visible and photoluminescence spectra revealed sub-band gap transitions at 2.17 and 2.38 eV, of which the latter might be ascribed to the oxygen vacancies  

    A study of the electrophoretic deposition of bioactive glass-chitosan composite coating

    , Article Ceramics International ; Volume 38, Issue 1 , January , 2012 , Pages 471-476 ; 02728842 (ISSN) Mehdipour, M ; Afshar, A ; Sharif University of Technology
    2012
    Abstract
    Bioactive glass is coated on implant's surface to improve corrosion resistance and osseointegration, when placed in the body. Bioactive glass particles were synthesized through a sol-gel process and deposited along with chitosan to form a composite coating on a stainless steel substrate using electrophoretic deposition technique. Stable suspensions of chitosan-bioactive glass were prepared using bioactive glass particles (<1 μm) and 0.5 g/l chitosan solution. The influence of ethanol-water ratio on deposition yield was investigated. For all process conditions, best results were achieved with suspension of 30 vol% water in ethanol-water containing 2 g/l bioactive glass. FTIR studies showed... 

    Physicochemical and biological properties of electrodeposited graphene oxide/chitosan films with drug-eluting capacity

    , Article Carbon ; Volume 84, Issue C , April , 2015 , Pages 91-102 ; 00086223 (ISSN) Ordikhani, F ; Ramezani Farani, M ; Dehghani, M ; Tamjid, E ; Simchi, A ; Sharif University of Technology
    Elsevier Ltd  2015
    Abstract
    In this study, novel graphene oxide/chitosan nanocomposite coatings with long term drugeluting potential are presented. The coatings are fabricated by the facile and reproducible electrophoretic deposition technique. Analysis of the prepared films shows that the graphene oxide nanosheets are exfoliated in the chitosan matrix. Fourier-transform infrared spectrometry reveals polymer attachment to the carboxylic bonds of graphene oxide, providing a strong interaction and exfoliation of the nanolayers. In vitro viability assay by human osteosarcoma cells (MG-63) demonstrates that the nanocomposite films are highly biocompatible up to 30 wt% graphene oxide, but at higher concentrations a slight... 

    Electrophoretic deposition of nano-zirconia coating on AZ91D magnesium alloy for bio-corrosion control purposes

    , Article Surface and Coatings Technology ; Volume 311 , 2017 , Pages 182-190 ; 02578972 (ISSN) Amiri, H ; Mohammadi, I ; Afshar, A ; Sharif University of Technology
    Elsevier B.V  2017
    Abstract
    Magnesium alloys are considered as potential biodegradable biomaterials in hard tissue implants. However, the fast degradation rate of these alloys in the biological environment causes failure of the implant just prior to the desirable time. In the present work, in order to decrease and curb the bio-corrosion rate of AZ91D Magnesium alloy, zirconia, which is classified as a biocompatible ceramic, was coated on the alloy surface through electrophoretic deposition (EPD) technique. The effects of alterations in the EPD parameters such as current density, duration time and ZrO2 particles concentration on coating properties including thickness, morphology and adhesion were then characterized.... 

    Carbon nanoparticles in high-performance perovskite solar cells

    , Article Advanced Energy Materials ; Volume 8, Issue 12 , 2018 ; 16146832 (ISSN) Yavari, M ; Mazloum Ardakani, M ; Gholipour, S ; Marinova, N ; Delgado, J. L ; Turren Cruz, S. H ; Domanski, K ; Taghavinia, N ; Saliba, M ; Gratzel, M ; Hagfeldt, A ; Tress, W ; Sharif University of Technology
    Wiley-VCH Verlag  2018
    Abstract
    In the past few years, organic–inorganic metal halide ABX3 perovskites (A = Rb, Cs, methylammonium, formamidinium (FA); B = Pb, Sn; X = Cl, Br, I) have rapidly emerged as promising materials for photovoltaic applications. Tuning the film morphology by various deposition techniques and additives is crucial to achieve solar cells with high performance and long-term stability. In this work, carbon nanoparticles (CNPs) containing functional groups are added to the perovskite precursor solution for fabrication of fluorine-doped tin oxide/TiO2/perovskite/spiro-OMeTAD/gold devices. With the addition of CNPs, the perovskite films are thermally more stable, contain larger grains, and become more... 

    A Study on Optoelectronic Properties of Copper Zinc Tin Sulfur Selenide: A Promising Thin-Film Material for Next Generation Solar Technology

    , Article Crystal Research and Technology ; Volume 56, Issue 7 , 2021 ; 02321300 (ISSN) Ali, N ; Zubair, M ; Khesro, A ; Ahmed, R ; Uddin, S ; Shahzad, N ; Alrobei, H ; Kalam, A ; Al-Sehemi, A. G ; Ul Haq, B ; Sharif University of Technology
    John Wiley and Sons Inc  2021
    Abstract
    Studies on copper zinc tin sulpher selenide (CZTSSe) thin-film material and its applications as a base material are intensively being researched since it is an earth-abundant, inexpensive, flexible, and interesting material for next-generation optoelectronic technologies. Apropos, this study explores and reports the synthesis of CZTSSe thin films and their key optoelectronics characteristics. The reported films are fabricated on a soda-lime glass substrate by using a physical vapor deposition technique, and then annealed from 250 to 450 °C. From the X-ray diffraction analysis, the structure of the as-deposited thin films is found to be amorphous in nature. Annealed thin films of CZTSSe... 

    A study on optoelectronic properties of copper zinc tin sulfur selenide: A promising thin-film material for next generation solar technology

    , Article Crystal Research and Technology ; Volume 56, Issue 7 , 2021 ; 02321300 (ISSN) Ali, N ; Zubair, M ; Khesro, A ; Ahmed, R ; Uddin, S ; Shahzad, N ; Alrobei, H ; Kalam, A ; Al Sehemi, A. G ; Ul Haq, B ; Sharif University of Technology
    John Wiley and Sons Inc  2021
    Abstract
    Studies on copper zinc tin sulpher selenide (CZTSSe) thin-film material and its applications as a base material are intensively being researched since it is an earth-abundant, inexpensive, flexible, and interesting material for next-generation optoelectronic technologies. Apropos, this study explores and reports the synthesis of CZTSSe thin films and their key optoelectronics characteristics. The reported films are fabricated on a soda-lime glass substrate by using a physical vapor deposition technique, and then annealed from 250 to 450 °C. From the X-ray diffraction analysis, the structure of the as-deposited thin films is found to be amorphous in nature. Annealed thin films of CZTSSe... 

    Electrophoretic deposition of bioactive glass coating on 316L stainless steel and electrochemical behavior study

    , Article Applied Surface Science ; Volume 258, Issue 24 , 2012 , Pages 9832-9839 ; 01694332 (ISSN) Mehdipour, M ; Afshar, A ; Mohebali, M ; Sharif University of Technology
    Elsevier  2012
    Abstract
    In this research, submicron bioactive glass (BG) particles were synthesized by a sol-gel process and were then coated on a 316L stainless steel substrate using an electrophoretic deposition (EPD) technique. Stable suspension of bioactive glass powders in ethanol solvent was prepared by addition of triethanol amine (TEA), which increased zeta potential from 16.5 ± 1.6 to 20.3 ± 1.4 (mv). Thickness, structure and electrochemical behavior of the coating were characterized. SEM studies showed that increasing EPD voltage leads to a coating with more agglomerated particles, augmented porosity and micro cracks. The results of Fourier transformed infrared (FTIR) spectroscopy revealed the adsorption... 

    Antibiotic-loaded chitosan–Laponite films for local drug delivery by titanium implants: cell proliferation and drug release studies

    , Article Journal of Materials Science: Materials in Medicine ; Volume 26, Issue 12 , December , 2015 ; 09574530 (ISSN) Ordikhani, F ; Dehghani, M ; Simchi, A ; Sharif University of Technology
    Kluwer Academic Publishers  2015
    Abstract
    Abstract: In this study, chitosan–Laponite nanocomposite coatings with bone regenerative potential and controlled drug-release capacity are prepared by electrophoretic deposition technique. The controlled release of a glycopeptide drug, i.e. vancomycin, is attained by the intercalation of the polymer and drug macromolecules into silicate galleries. Fourier-transform infrared spectrometry reveals electrostatic interactions between the charged structure of clay and the amine and hydroxyl groups of chitosan and vancomycin, leading to a complex positively-charged system with high electrophoretic mobility. By applying electric field the charged particles are deposited on the surface of titanium... 

    Corrosion resistance and photocatalytic activity evaluation of electrophoretically deposited TiO 2 -rGO nanocomposite on 316L stainless steel substrate

    , Article Ceramics International ; Volume 45, Issue 11 , 2019 , Pages 13747-13760 ; 02728842 (ISSN) Azadeh, M ; Parvizy, S ; Afshar, A ; Sharif University of Technology
    Elsevier Ltd  2019
    Abstract
    TiO 2 -rGO nanocomposite coatings were obtained by electrophoretic deposition (EPD) technique of TiO 2 nanoparticles and graphene oxide (GO) on stainless steel substrate. First, GO particles were synthesized using a modified Hummers' method. GO was reduced electrochemically to form a coating in the presence of nano-sized TiO 2 particles. The influences of different parameters such as GO concentration, coupling co-electro-deposition parameters (electrophoretic duration and voltage) on thickness, surface morphology and, corrosion behavior of the as-synthesized TiO 2 -rGO nanocomposite coatings were systematically surveyed. The morphology and microstructure were investigated by field emission...