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Investigation of synergistic effect of nano sized Ag/TiO2 particles on antibacterial, physical and mechanical properties of UV-curable clear coatings by experimental design
, Article Progress in Organic Coatings ; Vol. 77, issue. 2 , February , 2014 , pp. 502-511 ; ISSN: 03009440 ; Bastani, S ; Hashemi, M. M ; Sharif University of Technology
Abstract
The synergistic effect of nano titanium dioxide (10 and 30 nm) and nano silver (10 nm) as antibacterial agents were investigated on UV curable clear coating. Antibacterial and physical-mechanical properties of coating were optimized using experimental design in response surface method. Twenty different samples of nano Ag and nano TiO2 were prepared in this method. Antibacterial properties on Gram-negative bacteria (Escherichia coli) were investigated. The results revealed that using equal amounts of two sizes of nano TiO2 promote the antibacterial activity of nano Ag. So, the coating shows strong activity against E. coli. Physical-mechanical properties such as surface hardness, abrasion...
Synthesis and characterization of salep sulfate and its utilization in preparation of heavy metal ion adsorbent
, Article Journal of Applied Polymer Science ; Volume 130, Issue 4 , 2013 , Pages 3001-3008 ; 00218995 (ISSN) ; Doulabi, M ; Alamolhoda, A. A ; Tavakkoli, E ; Amirshekari, S ; Sharif University of Technology
2013
Abstract
A multicomponent polysaccharide obtained from dried tubers of certain natural terrestrial orchids was chemically modified by sulfonation using chlorosulfonic acid-dimethylformamide (HClSO3-DMF) complex as a reagent. For a structural characterization of salep sulfate 1H nuclear magnetic resonance (NMR), Fourier transform infrared (FTIR) spectra, and Thermogravimetric analysis (TGA) curves were recorded. The sulfate content of modified salep was determined using elemental analysis. This modified biopolymer was used to prepare a new environment-friendly heavy metal ion adsorbent, salep sulfate-graft-polyacrylic acid hydrogel (SS-g-PAA). Swelling rate and equilibrium water absorbency in various...
Biomimetic apatite layer formation on a novel citrate starch scaffold suitable for bone tissue engineering applications
, Article Starch/Staerke ; Volume 68, Issue 11-12 , 2016 , Pages 1275-1281 ; 00389056 (ISSN) ; Shahriarpanah, S ; Asadzadehzanjani, N ; Khaleghpanah, S ; Heidari, S ; Sharif University of Technology
Wiley-VCH Verlag
2016
Abstract
The formation of biomimetic bone-like apatite layers throughout the biopolymer-based hydrogel scaffold is an attractive approach in bone tissue engineering. Here, the starch scaffold was prepared using a combination of particulate leaching and freeze-drying techniques. The fabricated structures were then modified by citric acid to investigate the formation of bone-like apatite layer on the porous citrate-based scaffold after soaking in simulated body fluid (SBF). The Fourier Transform Infrared (FTIR) spectra and X-ray diffraction (XRD) patterns revealed that the B-type carbonated apatite has successfully deposited on the scaffold after immersing in SBF for 28 days. Indeed, high chemical...
Characterisation of nanocrystalline sulfated titania modified with transition metals and aluminum as solid acids for esterification
, Article Progress in Reaction Kinetics and Mechanism ; Volume 41, Issue 1 , 2016 , Pages 57-66 ; 14686783 (ISSN) ; Abolhasani, E ; Ghasemi, S ; Sharif University of Technology
Science Reviews 2000 Ltd
2016
Abstract
TiO2, transition metal (Cr, Mn, Fe, Co, Ni, Cu, and Zn)- and aluminum-doped TiO2 nanoparticles were prepared by the sol-gel technique. The sulfated catalysts were prepared by the impregnation method with H2SO4 solution. The catalysts were characterised by X-ray diffraction (XRD), BET surface area measurement, diffuse reflectance spectroscopy (DRS), and Fourier transform infrared (FTIR) techniques. The sulfate content of the metal-incorporated samples was considerably higher than for SO4 2-/TiO2. The metal doping brought about a considerable reduction in the extent of sulfate loss from the catalyst surface due to the wide dispersion on the surface. The SO4 2-/TiO2 and SO4 2-/M/TiO2...
Degradation of azo dye methyl red by saccharomyces cerevisiae ATCC 9763
, Article International Biodeterioration and Biodegradation ; Volume 125 , 2017 , Pages 62-72 ; 09648305 (ISSN) ; Bagheri Lotfabad, T ; Heidarinasab, A ; Yaghmaei, S
Abstract
Azo dyes are common dye groups widely used in different industries. Industrial effluents which contain these dyes pervade water resources and have various known and unknown physiological effects on living organisms. In this study, methyl red (MR) was proposed as a model azo dye to examine the capability of Saccharomyces cerevisiae ATCC 9763 for cleavage of the azo bond leading to decolourization. The spectrophotometry method showed that complete decolourization occurred statically during ≃12 h and this time reduced to several minutes less than 10 min where cell mass increased. Thin layer chromatography (TLC), mass spectroscopy and Fourier transform infrared (FTIR) confirmed degradation of...
Enhanced mechanical properties of chitosan/nanodiamond composites by improving interphase using thermal oxidation of nanodiamond
, Article Carbohydrate Polymers ; Volume 167 , 2017 , Pages 219-228 ; 01448617 (ISSN) ; Shojaei, A ; Sharif University of Technology
Elsevier Ltd
2017
Abstract
Polymer composite films based on chitosan (CS) and nanodimaond (ND) were prepared using solution casting method. ND with variable contents of carboxylic functional group was prepared using thermal oxidation at temperature of 420 °C under air atmosphere at various durations of 1.5 and 4.5 h. The interfacial interaction between NDs and CS and morphological evolution of CS in presence of NDs were investigated by Fourier transform infrared (FTIR), differential scanning calorimeter (DSC) and X-ray diffraction (XRD) analyses. A significant improvement in tensile strength (∼85%) and tensile modulus (∼125%) of CS was achieved by oxidized ND (OND) obtained at higher oxidation time of 4.5 at low...
Investigation of Tabas anthracite coal devolatilization: Kinetics, char structure and major evolved species
, Article Thermochimica Acta ; Volume 654 , 2017 , Pages 74-80 ; 00406031 (ISSN) ; Askari, M ; Fabritius, T ; Sharif University of Technology
Elsevier B.V
2017
Abstract
The pyrolysis of low-volatile Tabas anthracite coal was investigated by thermogravimetric technique (TGA) in the temperature range from ambient to 1100 °C under non-isothermal heating conditions (1.5, 3, and 7 °C/min heating rates). Higher heating rates showed a small retarding effect on devolatilization toward higher temperatures. Iso-conversional method was used for the kinetic study of non-isothermal Thermogravimetric data. Activation energy calculated for coal conversion of 20–80% was about 319 kJ/mol which may be a result of stable ordered structure of this type of coal. Analysis of evolved gases by Fourier transform infrared spectrometry (FTIR) in 7 °C/min heating rate was conducted...
Fouling control mechanism by optimum ozone addition in submerged membrane bioreactors treating synthetic wastewater
, Article Journal of Environmental Chemical Engineering ; Volume 6, Issue 6 , 2018 , Pages 7294-7301 ; 22133437 (ISSN) ; Hazrati, H ; Shayegan, J ; Sharif University of Technology
Abstract
In this paper, the effect of ozone on membrane fouling of membrane bioreactor (MBR) systems was investigated. Sludge specification such as soluble microbial product (SMP), extracellular polymeric substance (EPS), viscosity, particle size distribution (PSD), microscopic observations and sludge volume index (SVI) in presence of ozone were determined. Further, EPS, Fourier-transform infrared (FTIR) analysis, excitation-emission matrix (EEM) fluorescence spectroscopy, and gel permission chromatography (GPC) are considered to determine cake layer characteristics. The results indicated COD removal did not show significant difference with ozonation. Ozone also increases the particle size and...
Evaluation of UiO-66 metal organic framework as an effective sorbent for curcumin's overdose
, Article Applied Organometallic Chemistry ; Volume 32, Issue 4 , 2018 ; 02682605 (ISSN) ; Zamani, M ; Aghajanzadeh, M ; Kheiri Manjili, H ; Danafar, H ; Shojaei, A ; Sharif University of Technology
John Wiley and Sons Ltd
2018
Abstract
Metal organic frameworks (MOFs) UiO-66 (UiO stands for University of Oslo) and NH2-UiO-66 were prepared and characterized as sorbent (antidotal agents) for curcumin (CUR) adsorption. The structure of products were characterized by X-ray powder diffraction (XRD), Field emission scanning electron microscopy (FESEM), thermogravimetric analysis (TGA), Attenuated Total Reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), and N2 adsorption–desorption measurements. FESEM showed NH2-UiO-66 displayed symmetrical crystals with triangular base pyramid morphology, with the particle size around 100 nm and uniform size distribution. Adsorption capacities of CUR/MOFs with different mass ratios...
Self-assembly of tryptophan-capped gold nanoparticles onto DNA network template
, Article Journal of Dispersion Science and Technology ; Volume 30, Issue 2 , 2009 , Pages 254-258 ; 01932691 (ISSN) ; Vosoughi, M ; Alemsadeh, I ; Sharif University of Technology
2009
Abstract
In this study, a simple route to the formation of DNA-gold complex has been reported, using immobilized DNA as a template. The nanoporous gold films have been prepared by the electrostatic self assembly of gold nanoparticles capped with tryptophan. Tryptophan would improve surface properties of gold nanoparticles for strongly attaching to DNA. Fourier transform infrared spectroscopy confirmed that gold nanoparticles have been capped by tryptophan. Also measured zeta potential shows that there are positive charges on the surface of gold nanoparticles. Investigations by atomic force microscopy substantially confirm that tryptophan-capped gold nanoparticles can be bonded to DNA template...
Microstructure and characteristic properties of gelatin/chitosan scaffold prepared by the freeze-gelation method
, Article Materials Research Express ; Volume 6, Issue 11 , 2019 ; 20531591 (ISSN) ; Kamali, A ; Bahrani Fard, M. R ; Sharif University of Technology
Institute of Physics Publishing
2019
Abstract
Three-dimensional porous scaffolds are essential in tissue engineering applications. One of the most conventional methods to form porosity in scaffolds is freeze-drying, which is not energy efficient and cost effective. Therefore in this work, it was experimentally investigated whether gelatin, with its unique mechanical properties and cell binding applications, could be used as a comprising polymer of scaffolds with porous structure made by the freeze-gelation method. Chitosan, gelatin and chitosan/gelatin scaffolds were fabricated by the freeze-gelation method and their behaviors, determined by analysis of scanning electron microscopy images, Fourier transform infrared spectroscopy,...
Evaluation of the performance and temperature susceptibility of gilsonite- and SBS-modified asphalt binders
, Article Construction and Building Materials ; Volume 207 , 2019 , Pages 679-692 ; 09500618 (ISSN) ; Ameri, M ; Amini, A ; Sabouri, M ; Norouzi, A ; Sharif University of Technology
Elsevier Ltd
2019
Abstract
This study investigated the effect of gilsonite and Styrene-Butadiene-Styrene (SBS) as asphalt binder modifiers on the physical and rheological properties of asphalt binders. For this, binder tests such as penetration test, softening point, rotational viscosity (RV), Dynamic Shear Rheometer (DSR), and Bending Beam Rheometer (BBR) were conducted on the neat and modified binders. The effect of gilsonite and SBS on the binder temperature susceptibility was also investigated by measuring Penetration Index (PI), Activation Energy (AE) and Viscosity-Temperature Susceptibility (VTS) of all the study binders. Fourier-Transform Infrared Spectroscopy (FTIR) test was directed toward investigation of...
Mechanical and corrosion protection properties of a smart composite epoxy coating with dual-encapsulated epoxy/polyamine in carbon nanospheres
, Article Industrial and Engineering Chemistry Research ; Volume 58, Issue 8 , 2019 , Pages 3033-3046 ; 08885885 (ISSN) ; Ramazani, S. A ; Mahdavian, M ; Taheri, P ; Mol, J. M. C ; Sharif University of Technology
American Chemical Society
2019
Abstract
Carbon nanocapsules doped separately with epoxy and polyamine were used to fabricate an epoxy nanocomposite coating. Carbon nanospheres with dual-encapsulated epoxy/polyamine were dispersed uniformly in the epoxy resin at concentrations of 2, 5, and 10 wt %. The mechanical properties of the nanocomposites were studied by tensile testing and scratch hardness measurements. Furthermore, nanocomposites were applied on mild steel substrates, and their corrosion protection and barrier performance were evaluated using electrochemical impedance spectroscopy (EIS). Adhesion loss measurements of coatings after 240 h exposure to 3.5 wt % NaCl solution were performed by pull-off adhesion testing. Also,...
Development of a quartz crystal microbalance biodetector based on cellulose nanofibrils (CNFs) for glycine
, Article Journal of Materials Science: Materials in Electronics ; Volume 31, Issue 20 , 2020 , Pages 17451-17460 ; Iraji zad, A ; Vossoughi, M ; Kalantarian, A ; Sharif University of Technology
Springer
2020
Abstract
The performance of a quartz crystal microbalance (QCM) used as a sensor/detector relies on the performance and quality of the film coated onto the quartz crystal sensor. This study focuses on the sensor coating preparation for the detection of glycine. Cellulose nanofibrils (CNFs), natural polymers, were coated on a quartz crystal (QC) surface by a spin-coating method. The prepared CNF-coated QC was characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), cyclic voltammetry (CV), Fourier transform infrared spectrophotometry-attenuated total reflectance (FTIR-ATR), Raman spectroscopy, and water contact angle (WCA). The stable and fully covered QCs without further...
Room temperature selective sensing of aligned Ni nanowires using impedance spectroscopy
, Article Materials Research Express ; Volume 7, Issue 2 , 24 February , 2020 ; Fardindoost, S ; Iraji Zad, A ; Almasi Kashi, M ; Sharif University of Technology
Institute of Physics Publishing
2020
Abstract
Room temperature gas sensing behavior of arrayed one-dimensional (1D) nickel nanowires (Ni NWs) are investigated using impedance spectroscopy. Ni nanowires synthesized via electrochemical deposition method based on anodic aluminum oxide (AAO) templates. Their structural characterization verified by scanning electron microscopy (SEM), x-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FT-IR) analysis. Impedance spectroscopy as an essential technique utilized to understand the mechanism of gas interaction with the wires through the changes in their electronic behavior. Bode and Nyquist plots with the real and imaginary impedances are plotted versus frequency range of 500 Hz...
Self-assembly of dandelion-like hydroxyapatite nanostructures via hydrothermal method
, Article Journal of the American Ceramic Society ; Volume 91, Issue 10 , 2008 , Pages 3292-3297 ; 00027820 (ISSN) ; Mazloumi, M ; Mohajerani, M ; Kajbafvala, A ; Zanganeh, S ; Arami, H ; Sadrnezhaad, S. K ; Sharif University of Technology
2008
Abstract
Self-assembled dandelion-like hydroxyapatite (HAp) nanostructures were successfully synthesized via a mild template-free hydrothermal process, using ethylenediaminetetraacetic acid (EDTA) as the surfactant. The obtained dandelion-like HAp nanostructures were between 5 and 8 μm in diameter and were composed of radially oriented nanorods with an average diameter of about 200 nm. The X-ray diffraction analysis and Fourier transform infrared spectroscopy were used to characterize the crystalline phase and purity of the synthesized nanostructures. The Brunauer-Emmett-Teller surface area of the dandelion-like nanostructures was measured to be about 39 m2/g. The results of thermal analysis revealed...
Mechanistic investigation of the synergy of a wide range of salinities and ionic liquids for enhanced oil recovery: Fluid-fluid interactions
, Article Energy and Fuels ; Volume 35, Issue 4 , 2021 , Pages 3011-3031 ; 08870624 (ISSN) ; Maghsoudian, A ; Shirazi, M ; Tamsilian, Y ; Kord, S ; Sheng, J.J ; Sharif University of Technology
American Chemical Society
2021
Abstract
In this paper, the performance of three imidazolium-based ionic liquids (ILs) including 1-hexyl-3-methylimidazolium chloride ([HMIM][Cl] or IL6), 1-octyl-3-methylimidazolium chloride ([OMIM][Cl] or IL8), and 1- dodecyl-3-methylimidazolium chloride ([DMIM][Cl] or IL12) in reducing the interfacial tension (IFT) between crude oil and IL solutions was analyzed for the first time under a wide range of salinities (1000 to 195 476 ppm) at a reservoir temperature of 80 °C. The purpose was to microscopically analyze the occurring phenomenon at the fluid-fluid interface to determine the mechanism leading to oil extraction and to address the existing ambiguities in the literature concerning the...
Chemo-physical properties of renal capsules under ultraviolet-c exposure
, Article Journal of Applied Physics ; Vol. 116, Issue. 5 , 2014 ; ISSN: 00218979 ; Parvin, P ; Reyhani, A ; Mortazavi, S. Z ; Mokhtari, S ; Amjadi, A ; Sharif University of Technology
Abstract
The renal capsule tissue of lamb was irradiated with ultraviolet-C light and the treated samples were analyzed by uniaxial tensile test, dynamic mechanical analysis, attenuated total reflectance Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy and contact angle measurements. It was shown that the skin cross-linking is dominant in low doses in accordance with the contact angle assessment. Conversely, the strong bulk degradation takes place at high doses. Similarly, the bulk cross-linking affects the mechanical tests as to enhance the stiffness at low doses, whereas strong degradation occurs at high doses that mainly arises from the strong bulk chain scission
A novel approach for preparation of CL-20 nanoparticles by microemulsion method
, Article Journal of Molecular Liquids ; Vol. 193, issue , May , 2014 , pp. 83-86 ; Zarandi, M ; Zarei, M. A ; Soleyman, R ; Zeynali, V ; Sharif University of Technology
Abstract
2,4,6,8,10,12-Hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (CL-20) as one of the high energy cage nitramines has been used in various propellants and explosive formulations. The performance of energetic materials depends on its particle size and shape. Therefore, in this research, microemulsion method has been applied for the preparation of CL-20 nanoparticles via oil in water (O/W) microemulsions. The optimized formulation contains water 45%, n-butyl acetate 20.5%, sodium dodecyl sulfate (SDS, as anionic surfactant) 6.5% and 2-propanol (as co-surfactant) 26.5%. CL-20 nanoparticles that were obtained by microemulsion method are spherical with an average diameter of 25 nm, based on TEM image....
Fourier transform infrared spectroscopy: A potential technique for noninvasive detection of spermatogenesis
, Article Avicenna Journal of Medical Biotechnology ; Vol. 6, Issue. 1 , 2014 , pp. 47-52 ; ISSN: 2008-4625 ; Moazeni Pouracil, R. S ; Reza Sadeghi, M ; Sharif University of Technology
Abstract
Background: The seminal plasma is an excellent source for noninvasive detection of spermatogenesis. The seminal plasma of normospermic and azoospermic men has been analyzed for detection of spermatogenesis. Methods: Optical spectroscopy (Attenuated Total Reflectance-Infrared spectroscopy (ATR-IR) and Fourier Transform infrared spectroscopy (FT-IR) has been used to analyze the seminal plasma and the metabolome of seminal plasma for detection of spermatogenesis. Results The seminal plasma of normospermic and azoospermic men has been analyzed by ATR-IR. The results show that there is a pattern variation in the azoospermic men compared to normospermic men. However, the seminal plasma is too...