Search for: fourier-transform-infrared-spectroscopy
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    Improvement in CO2/H2 separation by fabrication of poly(ether-b-amide6)/glycerol triacetate gel membranes

    , Article Journal of Membrane Science ; Vol. 469, issue , 2014 , pp. 43-58 ; ISSN: 03767388 Rabiee, H ; Soltanieh, M ; Mousavi, S. A ; Ghadimi, A ; Sharif University of Technology
    The purpose of this study is to investigate separation performance of poly(ether-b-amide6) (Pebax1657)/glycerol triacetate (GTA) gel membranes for CO2 removal from H2, N2 and CH4. GTA as a low molecular weight and highly CO2-phill compound was added to membrane structure at various weight fractions, 20%, 40%, 60% and 80% of Pebax, to fabricate a new high solubility selective membrane with improved performance. Permeation of pure gases was studied at different temperatures from 25 to 65°C and pressures from 4 to 24bar and ideal selectivities were calculated. Results indicated enhancement in permeation for all tested gases. For example, at a pressure of 4bar and a temperature of 25°C, membrane... 

    Synthesis and characterization of gold nanotube/nanowire-polyurethane composite based on castor oil and polyethylene glycol

    , Article Materials Science and Engineering C ; Vol. 42 , 2014 , pp. 341-349 ; ISSN: 09284931 Ganji, Y ; Kasra,M ; Salahshour Kordestani, S ; Bagheri Hariri, M ; Sharif University of Technology
    Gold nanotubes/nanowires (GNT/NW) were synthesized by using the template-assisted electrodeposition technique and mixed with castor oil-polyethylene glycol based polyurethane (PU) to fabricate porous composite scaffolds for biomedical application. 100 and 50 ppm of GNT/NW were used to synthesize composites. The composite scaffolds were characterized by Fourier transform infrared spectroscopy, dynamic mechanical thermal analysis, differential scanning calorimetry, and scanning electron microscopy. Cell attachment on polyurethane-GNT/NW composites was investigated using fat-derived mesenchymal stem cells. Addition of 50 or 100 ppm GNT/NW had significant effects on thermal, mechanical, and cell... 

    Chemo-physical properties of renal capsules under ultraviolet-c exposure

    , Article Journal of Applied Physics ; Vol. 116, Issue. 5 , 2014 ; ISSN: 00218979 Baghapour, Sh ; Parvin, P ; Reyhani, A ; Mortazavi, S. Z ; Mokhtari, S ; Amjadi, A ; Sharif University of Technology
    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  

    Enhancement of efficient Ag-S/TiO2 nanophotocatalyst for photocatalytic degradation under visible light

    , Article Industrial and Engineering Chemistry Research ; Vol. 53, issue. 23 , 2014 , Pages 9578-9586 ; ISSN: 08885885 Feilizadeh, M ; Vossoughi, M ; Zakeri, S. M. E ; Rahimi, M ; Sharif University of Technology
    A new photocatalyst (Ag-S/PEG/TiO2) was synthesized by adding polyethylene glycol (PEG) to an efficient Ag-S/TiO2 photocatalyst, to obtain a photocatalyst that is highly active under visible light. In addition to Ag-S/PEG/TiO2, Ag-S/TiO2 and pure TiO2 were prepared to compare their properties and activities. Specifically, the morphologies and microstructures of the nanophotocatalysts were characterized by means of powder X-ray diffraction (XRD), N2 adsorption-desorption measurements, scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) microanalysis, transmission electron microscopy (TEM), UV-visible diffuse reflectance spectroscopy (DRS), photoluminescence (PL) spectroscopy,... 

    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 Bayat, Y ; Zarandi, M ; Zarei, M. A ; Soleyman, R ; Zeynali, V ; Sharif University of Technology
    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.... 

    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 Labbani-Motlagh, A ; Bastani, S ; Hashemi, M. M ; Sharif University of Technology
    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... 

    Influence of glycerol and clay contents on biodegradability of corn starch nanocomposites

    , Article International Journal of Engineering, Transactions B: Applications ; Vol. 27, issue. 2 , 2014 , pp. 203-214 ; ISSN: 10252495 Heydari, A ; Alemzadeh, I ; Vossoughi, M ; Sharif University of Technology
    In this study, biodegradation of corn starch/glycerol/Na-MMT nanocomposites by soil burial tests were carried out for up to 6 months. Films were prepared by casting method according to central composite design and response surface methodology was applied for analysis of the results. The effects of formulation on the water solubility, contact angle and tensile strength of starch films were investigated. Increasing in Na-MMT content decreased biodegradability; while presence of glycerol, increased it. The effect of nanoparticles content might have been attributed to interactions between starch and Na-MMT that further prevented enzymatic attack on the biopolymer. In addition, the films with... 

    Nano-magnetic poly (vinyl alcohol) hydrogels

    , Article Advanced Materials Research ; Volume 829 , 2014 , Pages 539-543 ; ISSN: 10226680 ; ISBN: 9783037859070 Asadi, S ; Frounchi, M ; Dadbin, S ; Sharif University of Technology
    Surface modified magnetic nanoparticles (M-NPs) were synthetized and stabilized in poly (vinylalcohol) solution. The solutions with various magnetic nanoparticles contents were gammairradiated and magnetic poly (vinyl-alcohol) (M-PVA) hydrogels were synthesized. The magnetic hydrogels and also the un-irradiated magnetic poly (vinyl alcohol) nanocomposite films were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), vibrating sample magnetometer (VSM), Fourier transform infrared spectroscopy (FTIR) and mechanical measurement. The M-NPs were uniformly dispersed in the polymer matrix due to a strong interaction between the surface-modified M-NPs and polymer matrix.... 

    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 Gilany, K ; Moazeni Pouracil, R. S ; Reza Sadeghi, M ; Sharif University of Technology
    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... 

    Enhancing glass ionomer cement features by using the HA/YSZ nanocomposite: A feed forward neural network modelling

    , Article Journal of the Mechanical Behavior of Biomedical Materials ; Vol. 29 , January , 2014 , pp. 317-327 ; ISSN: 17516161 Rajabzadeh, G ; Salehi, S ; Nemati, A ; Tavakoli, R ; Solati Hashjin, M ; Sharif University of Technology
    Despite brilliant properties of glass ionomer cement (GIC), its weak mechanical property poses an obstacle for its use in medical applications. The present research aims to formulate hydroxyapatite/yttria-stabilized zirconia (HA/YSZ) in the composition of GIC to enhance mechanical properties and to improve fluoride release of GIC. HA/YSZ was synthesized via a sol-gel method and characterized by applying X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), X-ray photo-emission spectroscopy (XPS) and simultaneous thermal analysis (STA) along with transmission electron microscopy (TEM) methods. The synthesized nanocomposite was mixed with GIC at a fixed composition of 5.... 

    Electrospun polyamide-polyethylene glycol nanofibers for headspace solid-phase microextration

    , Article Journal of Separation Science ; Vol. 37, issue. 14 , 2014 , pp. 1880-1886 ; ISSN: 16159306 Bagheri, H ; Najarzadekan, H ; Roostaie, A ; Sharif University of Technology
    A solution of polyamide (PA) containing polyethylene glycol (PEG) as a side low-molecular-weight polymer was electrospun. After synthesizing the PA-PEG nanofibers, the constituent was subsequently removed (modified PA) and confirmed by Fourier transform infrared spectroscopy. The scanning electron microscopy images showed an average diameter of 640 and 148 nm for PA and PA-PEG coatings, respectively, while the latter coating structure was more homogeneous and porous. The extraction efficiencies of PA, PA-PEG, and the modified PA fiber coatings were assayed by headspace solid-phase microextraction of a number of chlorophenols from real water samples followed by their determination by gas... 

    Effect of Ti-Zn substitution on structural, magnetic and microwave absorption characteristics of strontium hexaferrite

    , Article Journal of Alloys and Compounds ; Vol. 583, issue , 2014 , p. 325-328 Baniasadi, A ; Ghasemi, A ; Nemati, A ; Azami Ghadikolaei, M ; Paimozd, E ; Sharif University of Technology
    SrFe12-xTix/2Zn x/2O19 (x = 0-2.5) powders were synthesized by use of chlorides through co-precipitation method. The obtained powders were then milled by high energy ball mill to crash hard agglomerates and achieve nanoparticles. In order to evaluate microwave absorption versus frequency, composites including ferrite, as a filler, and matrix of polyvinylchloride (PVC) with weight ratio of 70% ferrite were prepared. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FE-SEM), vibrating sample magnetometer (VSM) and vector network analyzer (VNA) were employed to study the structural, magnetic and microwave absorption properties... 

    Core-shell γ-Fe2O3/SiO2/PCA/Ag-NPs hybrid nanomaterials as a new candidate for future cancer therapy

    , Article International Journal of Nanoscience ; Vol. 13, issue. 1 , February , 2014 Soleyman, R ; Pourjavadi, A ; Masoud, N ; Varamesh, A ; Sharif University of Technology
    In the current study, γ-Fe2O3/SiO 2/PCA/Ag-NPs hybrid nanomaterials were successfully synthesized and characterized. At first, prepared γ-Fe2O3 core nanoparticles were modified by SiO2 layer. Then they were covered by poly citric acid (PCA) via melting esterification method as well. PCA shell acts as an effective linker, and provides vacancies for conveying drugs. Moreover, this shell as an effective capping agent directs synthesis of silver nanoparticles (Ag-NPs) via in situ photo-reduction of silver ions by sunlight-UV irradiation. This system has several benefits as a suitable cancer therapy nanomaterial. Magnetic nanoparticles (MNPs) can guide Ag-NPs and drugs to cancer cells and then... 

    Grafting the sol-gel based sorbents by diazonium salts: A novel approach toward unbreakable capillary microextraction

    , Article Journal of Chromatography A ; Volume 1318 , November , 2013 , Pages 58-64 ; 00219673 (ISSN) Bagheri, H ; Bayat, P ; Piri Moghadam, H ; Sharif University of Technology
    The present work deals with a novel approach for grafting a sol-gel based sorbent, using diazonium salts for preparation of an unbreakable capillary microextraction (CME) device in on-line combination with high performance liquid chromatography (HPLC). The use of diazonium salts modifier allowed all types of metallic and non-metallic substrates to be used without any limitation. Substrates including copper, brass, stainless steel and polytetrafluoroethylene (PTFE) were chosen to be functionalized by chemical or electrochemical reduction of 4-amino phenyl acetic acid. Then, 3-(trimethoxysilyl)propylamine (3TMSPA) was selected as the precursor and the only reagent for preparation of the... 

    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) Pourjavadi, A ; Doulabi, M ; Alamolhoda, A. A ; Tavakkoli, E ; Amirshekari, S ; Sharif University of Technology
    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... 

    Comparison of kinetic biodegradation of potato starch based and corn starch based low density polyethylene compound in aerated sludge

    , Article BioTechnology: An Indian Journal ; Volume 7, Issue 5 , 2013 , Pages 163-168 ; 09747435 (ISSN) Borghei, M ; Khoramnejadian, S ; Hejazi, B ; Sharif University of Technology
    The biodegradability rates of two different kinds of polyethylene bonded with corn and potato starch are studied in this paper. While it is usual to use soil as the environment for biodegradation, an aerated sludge tank was used in this studywhich offers a richermicrobialmediumand increases the rate of biodegradation. The biodegradability is determined by two ways: first, comparing differences in the weight change of two samples, one placed inside distilled water and the other placed in aerated sludge tank. Second test for biodegradation is by examination of FTIR spectroscopy. Through FTIR spectroscopy, the biodegradability rate and reduction in some of the existing bonds in polymer before... 

    Synthesis of highly pure nanocrystalline and mesoporous CaTiO3 by a particulate sol-gel route at the low temperature

    , Article Journal of Sol-Gel Science and Technology ; Volume 68, Issue 2 , 2013 , Pages 324-333 ; 09280707 (ISSN) Mohammadi, M. R ; Fray, D. J ; Sharif University of Technology
    The low temperature perovskite-type calcium titanate (CaTiO3) thin films and powders with nanocrystalline and mesoporous structure were prepared by a straightforward particulate sol-gel route. The prepared sol had a narrow particle size distribution about 17 nm. X-ray diffraction and Fourier transform infrared spectroscopy revealed that, the synthesized powders had highly pure and crystallized CaTiO3 structure with preferable orientation growth along (1 2 1) direction at 400-800 °C. The activation energy of crystal growth was calculated 5.73 kJ/mol. Furthermore, transmission electron microscope images showed that the average crystallite size of the powders annealed at 400 °C was around 3.5... 

    Colloidal stability of dextran and dextran/poly ethylene glycol coated TiO2 nanoparticles by hydrothermal assisted sol-gel method

    , Article Ceramics International ; Volume 39, Issue 7 , 2013 , Pages 8377-8384 ; 02728842 (ISSN) Naghibi, S ; Madaah Hosseini, H. R ; Faghihi Sani, M. A ; Sharif University of Technology
    Colloidal stability of dextran (Dex) and Dex/poly ethylene glycol (PEG) coated TiO2 nanoparticles (NPs) were investigated. The particles were successfully synthesized by a hydrothermal assisted sol-gel technique. The results of Ultraviolet-visible (UV-vis) spectrophotometry showed that Dex and PEG additions during hydrothermal process (HTP) led to the formation of long-term (more than 60 days) stable colloids, while the addition of dispersants after HTP did not have a significant impact on the colloidal stability of NPs. X-ray diffraction (XRD) and selected area electron diffraction (SAED) analyses proved that PEG and/or Dex coated NPs had less crystallinity than the plain TiO2. Fourier... 

    Magnetic removal of crystal violet from aqueous solutions using polysaccharide-based magnetic nanocomposite hydrogels

    , Article Polymer International ; Volume 62, Issue 7 , 2013 , Pages 1038-1044 ; 09598103 (ISSN) Pourjavadi, A ; Hosseini, S. H ; Seidi, F ; Soleyman, R ; Sharif University of Technology
    Magnetic Fe3O4@SiO2 starch-graft-poly(acrylic acid) (SPAA) nanocomposite hydrogels were prepared and used as absorbents for removal of crystal violet from aqueous solutions. Dynamic swelling, effect of contact time, absorption kinetics and nanocomposite hydrogel mass for removal of crystal violet dyes from aqueous solutions were studied. Fourier transform infrared spectroscopy, scanning electron microscopy and vibrating sample magnetometer measurements were used for the characterization of the nanocomposite hydrogels. The nanocomposite hydrogels had high magnetic sensitivity under an external magnetic field, which allowed their magnetic separation from water, thus avoiding secondary... 

    Facile fabrication and characterization of amino-functionalized Fe 3O4 cluster@SiO2 core/shell nanocomposite spheres

    , Article Materials Research Bulletin ; Volume 48, Issue 6 , 2013 , Pages 2023-2028 ; 00255408 (ISSN) Kalantari, M ; Kazemeini, M ; Arpanaei, A ; Sharif University of Technology
    We developed a modified straightforward method for the fabrication of uniformly sized silica-coated magnetite clusters core/shell type nanocomposite particles. Proposed simple one-step processing method permits quick production of materials in high yield. The structural, surface, and magnetic characteristics of the nanocomposite particles were investigated by transmission electron microscopy (TEM), scanning electron microscope (SEM), powder X-ray diffraction (XRD), vibrating sample magnetometer (VSM), and Fourier-transform infrared (FTIR). The sphere-shaped particles almost have the average diameter of 120 nm, with a magnetic cluster core of 80 ± 15 nm, and a silica shell of 25 ± 10 nm...