فهرست مطالب

International Journal of Nano Dimension
Volume:6 Issue: 2, Spring 2015

  • تاریخ انتشار: 1393/10/22
  • تعداد عناوین: 13
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  • B. Khodashenas, H. R. Ghorbani Pages 111-127
    Developing reliable and eco-friendly processes for the synthesis of metallic nanoparticles is an essential step in the field of application of nanotechnology. Using natural factories such as biological systems is a way of developing such processes. Nowadays, the synthesis of silver nanoparticles is very common due to its numerous applications in different fields. The synthesis of these nanoparticles is carried out through physical, chemical and biological methods. However, due to its inexpensive and environmentally friendly features, the biological method is preferred to the other two methods. In the present article, the factors influencing the size of synthesized silver nanoparticles using biological methods (Which consists ofliving organisms such as: Plants, Fungi, Bacteria and Yeast) and the anti-bacterial properties of silver nanoparticles were investigated.
    Keywords: Silver nanoparticles, Biosynthesis, Effective factors, Silver precursor, Antibacterial
  • G. Chandra Das, D. Bhuyan, N. Sen Sarma, O. Kumar Medhi Pages 129-133
    A new approach for the synthesis of Prussian blue nanoparticles using the cationic surfactant Cetyl Pyridinium Chloride (CPC) as capping agent has been developed in the present work. Powder X-ray diffraction, transmission electron microscopy, UV–vis absorption spectra, and IR spectroscopy were employed to characterize the product. The TEM image showed that the Prussian blue nanoparticles with diameters of 8-22 nm were obtained. A particle size effect on optical and conductivity properties of the Prussian blue particles was observed. The higher value of activation energy for the nano compound compared to bulk Prussian blue indicates that the ionic conductions are predominant in the nano compound.
    Keywords: Nanoparticles, Transmission electron microscopy, Absorption spectra, Conductivity, X-ray diffraction
  • S. Sedaghat Pages 135-140
    Silver-Polyaniline (Ag-PANI) nanocomposites were prepared by in-situ oxidative polymerization of aniline monomer in sodium bis(2-ethylhexyl) sulfosuccinate (AOT) solution as an emulsifier. The synthesis of Silver-Polyaniline nanocomposites was investigated as a function of several parameters such as aniline concentration, concentration of emulsifier (AOT), concentration of oxidation agent and concentration of silver nitrate. The formation of Ag-PANI nanocomposite was characterized by scanning electron microscopy (SEM) in each stage of controlled parameters. The particle size of PANI was increased from 43 nm to 56 nm with decrease in aniline concentration. Moreover the particle size of silver nanocomposites decreased with increasing oxidation agent concentration. In addition, the nanoparticle size was raised with decrease of AOT concentration. Also, when the concentration of silver nitrate was decreased, the particle size of nanocomposites was decreased too. In vitro antibacterial tests were performed using Escherichia coli (E. coli) to determine the antibacterial capability of the Ag-Polyaniline nanocomposites.
    Keywords: Nanocomposites, Polyaniline, Silver nanoparticles, Micro emulsion, Antibacterial properties
  • E. Esmaeili, R. Ghazanfari, S. Farsad Pages 141-151
    In the current investigation, Fe3O4 water-based nanofluids were synthesized to examine the effect of an alternative 3-D external magnetic field on its thermal behavioral pattern. A solvothermal method was used to prepare the magnetite nanoparticles. To characterize the nanoparticles, the study employed transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, vibrating sample magnetometer and zeta-potential experiments. Vibrating sample magnetometer evaluations thoroughly confirmed the super-paramagnetic characteristics of the nanoparticles. Therefore, exposition of the resulting nanofluids to an AC external magnetic field led to the formation of aligned dipoles parallel to the applied field. Afterwards, the net magnetization in the absence of the external field was set to zero. Thermal measurements demonstrated an enhancement of convective heat transfer coefficients, particularly in the case of more diluted samples. The highest value of h was associated with the most diluted sample, where the h value was two times greater than that in the base fluid at V=1.4 V. This was attributed to the augmentation of both the Brownian motions and the viscosity gradients in the centerline of the test section.
    Keywords: External magnetic field, Convective heat transfer, Nanofluid, Magnetite, Magnetization
  • A. A. Dehno Khalaji, F. Malekan Pages 153-156
    In this study, we synthesis one-dimensional (1D) manganese(III) Schiff base coordination polymer [Mn(Brsalophen)(μ1,3-N3)]n by reaction of MnCl2·6H2O and tetradentate Schiff base ligand Brsalophen at the presence of NaN3 in methanol and characterized by elemental analyses (CHN) and FT-IR spectroscopy. It was used as a new precursor to prepare spinel type manganese oxide nanowires by a facile solid-state thermal decomposition in air at 400ºC for 3.5 h. The crystallinity, purity and morphology of the Mn3O4 products were characterized by powder X-ray diffraction (XRD) and scanning electron microscopy (SEM). The powder X-ray diffraction and scanning electron microscopy confirmed that the prepared Mn3O4 nanowires are pure single phases. The present method allows preparation of the Mn3O4 nanowires without expensive or toxic organic solvent and complicated equipment. The nanowires have a diameter about ≈25 nm and length exceeding 1.5 μm. It has potential to be applied as a general method for preparation of other transition metal oxide nanoparticles.
    Keywords: Manganese (III), Nanowires, Thermal decomposition, XRD, SEM
  • N. Bahrami Panah, R. Vaziri Pages 157-165
    The structure and the electronic properties of single-walled zigzag BN and B3C2N3 nanotubes (n, 0; n=4–10) were investigated using first-principles calculations based on a density functional theory. A plane–wave basis set with periodic boundary conditions in conjunction with Vanderbilt ultrasoft pseudo-potential was employed. The energy gap of ZB3C2N3NTs was calculated and compared with the corresponding value for BNNTs. It was found that in both types of nanotube (BNNTs and B3C2N3NTs), the band gap energy is increased as the diameter of the tubes becomes larger and also these nanotubes are semiconductors with direct band gap. Although the band gap energy of the BN tubes are much larger than that of B3C2N3 ones, they have similar dependence on the diameter of the tubes and a semiconducting characteristic is maintained. There is a peak near the conduction band in B3C2N3NT nanotubes. Thus, energy gaps are reduced. These kind of ternary BCN nanotubes are of n–type semiconductors.
    Keywords: First, principles calculations, Boron Nitride nanotube, B3C2N3 nanotube, Electronic properties, Density functional theory (DFT)
  • A. Pourasghar, S. Kamarian Pages 167-175
    Effective elastic properties for carbon nanotube reinforced composites are obtained through a variety of micromechanics techniques. An embedded carbon nanotube in a polymer matrix and its surrounding interphase is replaced with an equivalent fiber for predicting the mechanical properties of the carbon nanotube/polymer composite. The effects of an interphase layer between the nanotubes and the polymer matrix as result of effective interphase layer is investigated. A modeling analysis investigating the effect of the aspect ratio on the tubes reinforcement mechanism has been carried out. The variations of mechanical properties with tube reduce, interphase thickness and waviness is investigated. Furthermore in this work, the classical theory concerning the mechanical efficiency of a matrix embedding finite length fibers has been modified by introducing the tube-to-tube Random Contact which explicitly accounts for the progressive reduction of the tubes effective aspect ratio as the filler content increases.
    Keywords: Equivalent fiber, Effective interphase model, Waviness, Aspect ratio, Mechanical properties
  • E. Ghobadi, M. Hemmati, Gh. Khanbabaei, M. Shojaei, M. Asghari Pages 177-181
    Polyurethane/zeolite 13X nanocomposite films were fabricated using solution casting method. The synthesized nanocomposite films were structurally characterized using SEM, TGA and tensile analysis. SEM images showed appropriate distribution of nanocrystalline zeolite particles within polyurethane matrix. Better thermal stability of nanocomposite films in comparison to neat polyurethane was shown in TGA analysis. The tensile analyses were carried out for neat polyurethane (PU) and nanocomposite PU/zeolite 13X films. Adding 5 wt. % of nanozeolite 13X into the polymer matrix caused tensile strength to increase but by increasing zeolite content to 10wt. % and 20wt. % tensile strength decreased. Also, comparison of young’s modulus of samples showed that the young’s modulus and thus stiffness of composites increased with increasing the zeolite content. Strain at breaking point of nanocomposites decreased by increasing the zeolite content, as well.
    Keywords: Polyurethane, Zeolite 13X, Young's modulus, Nanocomposite, Tensile, Thermal
  • P. Yarmohamadi, M. Arabi Pages 183-188
    Silver salts and nanosilver (NS) are the common antimicrobial used in the treatment of chronic wounds, so they are important to assess their dermal toxicity. Therefore, in this study, the possible dermal toxicity of NS particles and silver nitrate (AgNO3), was tested by determining the serum level of transforming growth factor-β1(TGF-β1) and study on of mouse skin tissue. In this study, 30 BALB/c mice were randomly allocated into NS, AgNO3 and control groups (n=10). After general anaesthesia and shaving the back of all animals in near the vertebral column, in NS group, a volume of 50µl 10 µg/ml of nanosilver solution (40 nm), in AgNO3 group, with the same amount of AgNO3 solution (100 µg/ml), in control group, the same amount of distilled water was added to the sterile bandage of mice. The shaved areas were covered with sterile bandage that and fixed with cloth glue. After 3 and 7 days, the bandages were opened and serum level of TGF-β1 was measured using standard kits and preparation of skin samples for histological analysis. Results showed toxicity of NS and AgNO3 by a significant reduction of TGF-β1 without any damage to skin.
    Keywords: Nanosilver, Silver nitrate, Dermal toxicity, Skin, TGF, β1
  • H. Rasooli Saghai, S.K. Seyyedi Sahbari, S. Zabihi Agdam Pages 189-195
    In order to implement an integrated optical quantum circuit, designing waveguides based on the quantum box is of prime importance. To do this we have investigated optical waveguide both with and without optical pumping. The rate of absorption and emission using an array of AlGaAs/GaAs quantum box core/shell structure in the optical waveguide with various pumping intensities has computed. By considering an external pumping with maximum emission, the gain of the optical waveguide based on the AlGaAs/GaAs quantum box core/shell structure, for two different sizes 3×3×3 nm and 6×6×6 nm has been optimized. We have shown that in the absence of any external excitation with different pumping power, the amount of absorption energy in the array of quantum box is greater than the amount of emission energy, and resulting in the positive gain. Finally, we noticed that by increasing the dimension of the quantum box, the optimum gain is achieved for the smaller wavelength.
    Keywords: Quantum dot waveguide, Absorption, Emission, Gain, Nextnano
  • Mohamed Yacoob Syed Ali, V. Anuradha, N. Yogananth, R. Rajathilagam, A. Chanthuru, S. Mohamed Marzook Pages 197-204
    To identify the larvicidal activities of silver nanoparticles synthesized with Acanthus ilicifolius (A. ilicifolius) leaf extract against the larvae of Armigeressubalbatus and Aedesaegypti. In vitro larvicidal activities such as LC50 and LC90 were assessed for the A. subalbatus and Ae.aegypti larval species. Further, characterization using different techniques such as UV, SEM,EDAX, XRD and FTIR analysis were carried out for the synthesized silver nanoparticles. The LC50 value of the synthesized silver nanoparticle was determined as0.532 and 0.754mg/L for A. subalbatus and Ae. aegypti respectively. Further, the LC90 values are also determined as 2.13 and 5.98mg/L for A. subalbatus and Ae. aegypti respectively. The synthesized silver nanoparticles have maximum absorption at 420 nm with the average diameter ˃180 nm. The Energy Dispersive Analysis of X-rays (EDAX) spectrum revealed the presence of silver metal in synthesized nanomaterials. The XRD data showed 2θ intense values with various degrees such as 37.10°, 47.66°, 63.97° and 70.01°. The FTIR data showed prominent band at 3,400 cm-1 and is assigned to the O–H stretching of H-bonded alcohols and phenols. The band at 2,925 cm-1 is attributed to O–H stretching of carboxylic acids. The band at 1,616 cm-1, corresponds to the N–H bending of primary amines. The bands at 1,444 and 1,521 cm-1 are related to the C–C stretching of aromatic ring structure and the characteristic peak at 1,360 cm-1corresponds to the C–N stretching of aromatic amine group whereas in the region of 1,150–1,282 cm-1 are corresponding to the C–C stretching alcohols, carboxylic acids, ethers and esters. The significance of above results clearly indicate that no toxicity developed biosynthesis of silver nanoparticles with leaf aqueous extract of A. ilicifolius provides potential source for the larvicidal activity against mosquito borne diseases.
    Keywords: Acanthus ilicifolius, Biosynthesis, Dengue, LC50, LC90, Mangrove, Silver nanoparticles
  • S. Sadeghian Motlagh, F. Najafi Pages 205-210
    Aluminophosphate-5 (AlPO4-5) nano-pore zeolite was synthesized. The effect of alteration in precursor gel preparation on the morphology of zeolite was studied. The effect of variety of synthesis conditions on the purity, crystal and pore size, and crystallinity of AlPO4-5 zeolite been studied. A hydrothermal synthesis has been used to produce nano-pore Aluminophosphate-5 crystals. The crystals were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM). The morphology of crystals was changed by alteration on precursor gel. The size of crystals decreased from 10 to 2 micrometer when the aging time of precursor gel was changed from 2 to 12 h. The results also showed that the aluminum triisopropylate, as Aluminum source, has been affected the crystals morepure than the crystals were synthesized by aluminum hydroxide. The Al source was changed affected factors such as the pH precursor gel and then changed the morphology of crystals. The SEM analysis and Debye-Scherrer equation showed that the average particle size is about 58 nm.
    Keywords: Nano, pore, AlPO4, 5, Precursor gel, Preparation, Morphology
  • H. Noorizadeh, Y. Zeraatkish Pages 211-216
    This study reports the simple process to synthesis of CuO/CuI nanocomposite in a non-aqueous solution. In the conducted experiments CuI and Dimethyl Sulfoxide (DMSO) were used as the precursors. Moreover, DMSO had role of solvent and ligand simultaneously. In experiments the effects of oleic acid as the particles size modifier, temperature and concentration were investigated. Crystalline structure, size and shape of the CuO/CuI nanocomposite were characterized using X-ray diffraction (XRD), and scanning electron microscopy (SEM) techniques, respectively. The results indicated that particles size is less than 50 nanometers and are spherical and mono-dispersed in shape and size. In addition, the Crystallite sizes were estimated via the Scherrer equation.
    Keywords: XRD, CuO, CuI, SEM, X-ray, Nanocomposite