فهرست مطالب

  • Volume:3 Issue: 2, 2014
  • تاریخ انتشار: 1393/08/04
  • تعداد عناوین: 8
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  • Hamid Reza Taghiyari*, Olaf Schmidt Pages 65-73
    Wood is a naturally renewable material with both continuous and isolated pore systems. Wood-composite panels have the privilege of offering a homogeneous structure to be used as constructional and structural materials. However, its nature makes it susceptible to biological wood-deteriorating agents, water absorption and thickness swelling, fire, etc. Using nano-materials are very easy in the wood-composite industry due to the possibility to apply nano-material suspensions as in-process treatment. An overview of the research project carried on applying nano-materials in wood-composite panels proved numerous potential applications of nano-technology in this industry. The use of metal (nanosilver, nanocopper, and nano zinc-oxide) and mineral nanomaterials (nano-wollastonite) with high thermal conductivity coefficient helped improving thermal conductivity and better cure of the resin, resulting in a significant decrease in hot-press time, an improvement in physical and mechanical properties, as well as a decrease in gas and liquid permeability values. The water repellent property of silane nano-particles prevented the penetration of water and vapor into wood-composite matrix, resulting in a potential increase in the service life of the parts used in the furniture or structure would significantly increase. The applications are expected to rapidly expand and cover many other areas in the near future.
    Keywords: Nanotechnology, Porous Structure, Renewable materials, Thermal conductivity, Wood, composite panels
  • Alireza Badiei*, Zohreh Bahrami, Ali Jahangir, Ghodsi Mohammadi Ziarani Pages 75-80
    A carrier system based on nanoporous silica (SBA-15) with magnetic nanoparticles of CoFe2O4 was synthesized via the impregnation of cobalt salt, iron salt and citric acid with as-synthesized SBA-15. The obtained samples were characterized by small angle X-ray scattering (SAXS), N2 adsorption/desorption, scanning electron microscopy (SEM), vibrating sample magnetometer (VSM) and ultraviolet (UV) spectroscopy.The effect of magnetization on the drug release behavior of SBA-15 has been studied. Ibuprofen was chosen as a model drug. Drug release studies in simulated body fluid (SBF) at pH 7.4 showed that after 48 hours, the percentage of drug release through SBA-15 and magnetic SBA-15 could reach up to 80% and 20%, respectively. The obtained results reveal that the magnetization leads towards significant decrease of the drug release rate.
    Keywords: SBA, 15, CoFe2O4, Ibuprofen, Drug release, Magnetism
  • Kaykhosrow Khojier*, Lida Ahmadkhani Pages 81-88
    Aluminum alloys such as Al 5083 have primary potential for lightweight structural application in automotive and aerospace industries. This paper addresses the mechanical and tribological properties and corrosion resistance of chromium nitride coatings deposited on Al 5083 that can be used for development of applications of aluminum 5083 alloy. The CrN coatings of 1 μm thickness were deposited by DC reactive magnetron sputtering technique on the Aluminum 5083 wafers at different substrate temperatures (RT and 200°C) and bias voltages (-200 and -400 V). A FESEM instrument was used for study of chemical composition, and cross-section and surface imaging. The surface physical morphology of samples was also investigated by an atomic force microscope. The mechanical and tribological properties of the films were measured by nano-indentation and scratch tests, respectively. The electrochemical behaviorand corrosion resistance of the samples were examined in NaCl (3.5%) solution using potentiodynamicmethod. The results showed that the chromium nitride coatingscaused improvementof Al 5083 properties. The results also showed the best mechanical and tribological properties and corrosion resistance for deposited coating at room temperature and -400 V bias substrate voltage. The morphological studies demonstrated that these behaviors were due to the smooth surface with compact and small grains.
    Keywords: CrN, Al 5083, Bias voltage, Substrate temperature, Hardness, Corrosion resistance
  • Mohammad Javad Taghizadeh*, Khosrow Jadidi Pages 89-97
    An efficient one-pot three-component procedure for the synthesis of new chiral spiro-oxindolopyrrolizidines with highly regio-, diastereo-, and enantioselective from 1,3-dipolar cycloaddition of azomethine ylides and optically pure active cinamoyl oxazolidinone are described. The process occurs at room temperature in aqueous ethanol as green solvent and in the absence of any bidentate chelating Lewis acids. The oxazolidinone chiral auxiliary has been attached to the dipolarophile and removed from the cycloadducts in a non-destructive method. The mechanism of the reaction is discussed on the basis of the assignment of the absolute configuration of one of the cycloaddition products, which obtained by X-ray single crystal structure analysis, and theoretical calculations.
    Keywords: Proline, Spirooxindole, Oxazolidinone, Oxazolidinone chiral, Chiral pyrrolidines
  • Mehrnoosh Khaleghian*, Gholamreza Ghashami, Fatemeh Azarakhshi Pages 99-109
    To investigation non-bonded interaction of the [CuF4]2- complex inside nanoring, we focus on the single wall boron-nitride B18N18 nanoring. Thus, the geometry of B18N18 nanoring has been optimized by B3LYP method with EPR-II basis set and geometry of the [CuF4]2- complex has been optimized at B3LYP method with Def2-TZVP basis set and Stuttgart RSC 1997 Effective Core Potential. Also electronic delocalization between donor and acceptor bonds has been calculated by DFT method. Then we have been investigated the lowest unoccupied molecular orbital (LUMO) and the highest occupied molecular orbital (HOMO) for the lowest energy have been derived to estimate the structural stability of the B18N18-[CuF4]2- nanosystem, and the coefficients and hybrids of s, p and d orbitals of Cu and F involved in systemscan be distinguished based on these NBO data. The second order perturbation theory analysis of fock matrix in NBO of the molecules and the systems have been investigated at B3LYP method and Lewis σ-type (donor) and non-Lewis σ*-type (acceptor) and ΔE in different loops of the nanorings have been calculated. The Gaussian quantum chemistry package is used for all calculations.
    Keywords: DFT, Dipole moment, ECP, EPR, II basis set, HOMO, LUMO, NICS
  • Farhad Hatamjafari Pages 111-115
    One of the most important goals in medicinal chemistry is the development of new techniques and new heterocyclic compounds with pharmaceutical activity. The present study aimed to use a method for the synthesis of some 1,2-Dihydro-1-arylnaphtho [1,2-e] [1,3] oxazine-3-ones. The question this study tried to answer was this reaction can be performed in present of nano-Fe2O3 as an acid catalyst and solvent-free conditions or not. Therefore, to find answer to the question, some of the1,2-Dihydro-1-arylnaphtho [1,2-e] [1,3] oxazine-3-one derivatives with medicinal properties were synthesized with rapid, high yield, novel, facile, and one-pot condensation of β-naphthol, aromatic aldehydes and urea using by nano-Fe2O3 under solvent-free conditions. The one-pot synthesis on solid inorganic support provides the products in good yields. The synthesized some of oxazine-3-one derivatives has been reported.Nano-Fe2O3 was reused for four runs without significant loss of activity and the effect of the solvents on the model reaction was carried out in various solvents.
    Keywords: Naphthoxazinones, Naphthols, Three, component Reactions, Solvent, Free, Nano, Fe2O3
  • Meysam Sadeghi*, Sina Yekta, Nooshin Shahabfar, Mirhassan Husseini, Hadi Adeli, Mohammad Javad Taghizadeh Pages 117-123
    In this scientific research, MnO2 nanoparticles (NPs) have been successfully prepared by a precipitation method using KMnO4, MnSO4.H2O and H2O2 (30%) as the precursors. As-prepared sample was identified by X-ray diffraction (XRD), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM) and Infrared (IR) techniques. The transmission electron microscopy (TEM) showed 7-8 nm ranges size of as prepared MnO2 nanoparticles. The decontamination reaction of triethyl phosphate (TEP) as a chemical warfare nerve agent simulant (CWNAS) was carried out on the surface of MnO2 NPs as the sorbent catalyst with the different weight ratios of TEP/MnO2 (1:8, 1:16 and 1:32) and studied by using phosphorous-31 nuclear magnetic resonance spectroscopy (31PNMR) technique. The 31PNMR analysis results proved that more than 95% of TEP was adsorbed on this catalyst in decane solvent with ratio of 1:32 after the elapse of the reaction time (8 h) at room temperature (25±1°C). On the other hand, decontaminated agent simulant amounts for the ratios of 1:16 and 1:8 were lower under similar conditions, respectively. This sorbent catalyst provides enough surface area and enhanced chemical reactivity for instantaneous adsorption and decontamination of TEP.
    Keywords: MnO2 Nanoparticles (NPs), Precipitation, Catalyst, Decontamination, Nerve agent simulant, Triethyl phosphate (TEP), Adsorption
  • Maryam Aghazadeh*, Fatemeh Aghazadeh Pages 125-130
    The structural and electrical properties of polyaniline-cobalt sulphate nanocomposite prepared by chemical method.Polyaniline-cobalt sulphate nanocomposites were synthesized by the cobalt sulphate and ammonium persulphate and aniline.This paper reports on chemical technique using for synthesis of cobalt nanoparticles in the composite bridge is aniline. Electrical conductivity of polyaniline with cobalt sulphatena noparticles measured. Increasing amounts of cobalt nanoparticles in the sample equivalent to the highest electrical conductivity. We also studied morphology of polyaniline-cobalt sulphate nanocomposite. Size of cobalt nanoparticles, is ~ 65-75 nm.
    Keywords: Polyaniline, CobaltSulphate, Conductive polymer, Electricalconductivity, Nanocomposites Chemical method, Properties of cobalt