فهرست مطالب

Nanoscience and Nanotechnology - Volume:14 Issue:1, 2018
  • Volume:14 Issue:1, 2018
  • تاریخ انتشار: 1397/01/05
  • تعداد عناوین: 9
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  • S. Z. Aghamohammadi * Pages 1-10
    The Narumi-Katayama index is the first topological index defined by the product of some graph theoretical quantities. Let G be a simple graph. Narumi-Katayama index of G is defined as the product of the degrees of the vertices of G. In this paper, we define the Narumi-Katayama polynomial of G. Next, we investigate some properties of this polynomial for graphs and then, we obtain this polynomial for some composite graphs such as splice, link, join, composition and Cartesian product of two graphs. Finally, using our results, we compute this polynomial for some nanostructures such as dendrimers and the chain of fullerenes.
    Keywords: Narumi-Katayama polynomial, Coefficients of a polynomial, Nanostar dendrimers, Fullerenes
  • A. Farazas, A. Mavropoulos *, D. Christofilos, I. Tsiaousis, D. Tsipas Pages 11-17
    Graphene oxide (GO) was prepared by an improved green chemical method using graphite flakes, KMnO4, a mixture of H2SO4/H3PO4, H2O2 and HCl. In several stages, ultrasound was used to separate the oxidized layers of GO. The use of ultrasound optimizes the effect of the reacting agents, decreasing the required amounts of used chemicals. This method produces graphene oxide highly oxidized with greater interlayer spacing over the Hummers’ method without producing toxic gases. The final product was characterized by UV-VIS, XRD, optical microscopy, TEM and Raman Spectroscopy and all used techniques verified the desirable outcome. The results showed that this low cost method is fully scalable without producing undesirable environmental effects.
    Keywords: Graphene oxide, Green synthesis, Ultrasound
  • A. Naeimi Bagheini *, M. Saeidi, N. Boroomand Pages 19-32
    A magnetically recoverable adsorbent has been prepared by silica-coated magnetic nanoparticles through an amine functionality (ASMNPs). The ASMNPs were characterized by XRD, TEM, SEM, and FT-IR spectroscopy. It was used as an efficient and economical adsorbent for removing O, O-Diethyl O-[4-methyl-6-(propan-2-yl) pyrimidin-2-yl] phosphorothioate (diazinon) from contaminated water through batch experiments. The results were shown that 84% of diazinon was removed after 30 min. The experimental data of the adsorption kinetics were well described by Pseudo-second-order kinetic model (R2>0.99), and Equilibrium adsorption data could be better fitted with the Freundlich isotherm (R2>0.99). The standard free energy change (ΔG°) and standard enthalpy change (ΔH°) were indicated that this system is a spontaneous and exothermic process.
    Keywords: Magnetic, Adsorption, Spectrophotometry, Pesticides, Water
  • R. Sowbarnika *, S. Anhuradha, B. Preetha Pages 33-42
    In recent science Nanotechnology is a burning field for the researchers. To meet the requirements and growing technological demand, there is a need to develop an eco-friendly approach. In the present effort, the baker’s yeast (Saccharomyces cerevisiae) has been taken in order to assess its potential as putative candidate fungal genera for the transformation of silver nanoparticles. Silver nanoparticles were successfully synthesized from Saccharomyces cerevisiae by green synthesis method. The formation of silver nanoparticles and the concentration of yeast extract required to produce yeast mediated silver nanoparticles with no aggregation was found out by UV-Visible spectroscopic analysis. The detailed characterization of the Ag NPs was carried out using Scanning Electron Microscopy (SEM), and FTIR. From the UV-visible spectroscopy, the maximum absorption peak was found at 440 nm. From the SEM images, it is confirmed that the sample contains spherical silver nanoparticles at a range of 10 to 60 nm. The silver nanoparticles are crystalline in nature, which was confirmed by the FT-IR peak at 518 cm-1 corresponding to the Ag vibration present in crystalline structure. The water filtration system depicted 5 log reduction for AgNPs [99.99% reduction]. The antibacterial activity of silver nanoparticles was determined by well diffusion method, and found that silver nanoparticles have significant antibacterial activity against E. coli with an inhibition zone of 2.1cm. The MIC test was performed to test the inhibitory concentration of AgNPs against the pathogens and was found to be 40 µg ml-1 for E.coli and comparatively higher for other microorganisms.
    Keywords: Nanoparticles, Water filtration, Log reduction, Minimum inhibitory concentration
  • T. Taghizade Firozjaee *, N. Mehrdadi, M. Baghdadi, G. R. Nabi Bidhendi Pages 43-56
    In recent years, water pollution and pesticide residues in the food chain have become a serious environmental and health hazard problem. Therefore, an efficient technology is essential for complete mineralization of pesticides to non-toxic forms. Nanotechnology offers many potential benefits to improve existing environmental technologies using new materials with effective performance, resulting in less consumption of energy and materials. The aim of this review is to compile and study current publications regarding pesticides removal by nanotechnology. This study discusses the applications, advantages and limitations various nanotechnology processes for removal of pesticides.
    Keywords: Pesticide, Removal, Nanotechnology, Environment, Water
  • F. Tari, M. Manteghian *, S. Tazarv Pages 57-64
    Nickel-molybdenum oxidebimetallic nanoparticles were synthesized in ethylene glycol using the microwave irradiation technique. According to the results, successive reduction of nickel and molybdenum ions, followed by thermal treatment of obtained nanoparticles led to formation of core-shell structured nickel-molybdenum oxide nanoparticles. According to the results, the thickness of the shell and core were 5 and 40 nm, respectively. The structure and composition of nanoparticles were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), UV-vis spectroscopy, scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS).
    Keywords: Core-shell nanoparticles, Nickel-Molybdenum oxide, Microwave polyol
  • Z. Khayyat Sarkar *, V. Khayyat Sarkar Pages 65-70
    The presented study investigates application of polyethylene glycol (PEG)-coated Fe3O4 nanoparticles as an magnetic nanoadsorbent for magnetic solid-phase extraction (SPE) and the selective removal of toxic heavy metals such as mercury (II) from aqueous solutions and their determination using graphite furnace atomic absorption spectrometry (GF-AAS). The Fe3O4 magnetic nanoparticles were synthesized using co-precipitation and characterized by Scanning electron microscopy (SEM), X-ray diffraction (XRD) and vibrating-sample magnetometer(VSM). The influences of analytical parameters including pH andeluent type, concentration and volume have been studied and optimized. The optimum pH required for maximum adsorption was found to be 6 for mercury. SEM images showed that the particle- size was about 24 nm and no marked aggregation occurred. XRD indicated the sole existence of inverse cubic spinel phase of Fe3O4 magnetic nanoparticles. VSM patterns indicate superparamagnetic of Fe3O4 magnetic nanoparticles. The results obtained from the recovery test showed the capability and reliability of the method for the removing mercury (II) from wastewater.
    Keywords: Hg(II), Polyethylene glycol (PEG-4000) coated Fe3O4 Magnetic nanoparticles, Co-precipitation, Wastewater
  • H. Panahi *, S. Asadi Pages 71-83
    Spreading and coating of nano and micro droplets on solid surfaces is important in a wide variety of applications including plasma spray coating, ink jet printing, DNA synthesis and etc. In spraying processes, most of droplets collide obliquely to the surface. The purpose of this article is to study the distribution of nano and micro droplets spreading when droplets impact at an oblique angle. We introduce the generalized exponential distribution as a new alternative for spreading data. The generalized exponential distribution shares many physical properties of the Weibull distribution which is used frequently for engineering data. For shape parameter greater than one, the generalized exponential distribution offers increasing hazard function, which is in accordance with the inclined droplet impact in plasma coating processes. We apply a number of criteria and model selection tests to evaluate the suitability of the generalized exponential distribution to other rival models, such as the Weibull, inverse Weibull, Burr III, Burr X, inverted exponentiated Rayleigh and exponentiated Pareto distributions. The analyses results indicate that the generalized exponential distribution shows better results than the other distributions for nano and micro droplets spreading data. Finally, graphical displays for informal checks on the appropriateness of the generalized exponential distribution in probabilistic assessment of inclined impact as well as formal goodness of tests are presented. An important implication of the present study is that the generalized exponential distribution, in contrast to other distributions, fits more appropriately in the spreading data.
    Keywords: Generalized exponential distribution, Model selection procedures, Oblique collision, Plasma spray, Nano, micro droplets
  • M. Yuonesi * Pages 85-92
    Physical study of nano ribbon, tetragonal bundled and isolated nano tube SiC (7,0) are part of our project in knowing new nano material such a silicon carbide. These studies have been performed by density function theory. Effect of ribboning, tubulating and tetragonal bundling on the physical properties such as stability, structural constants, optical physics, chemical parameters and magnetization have been investigated by PWSCF software. These factors are very important tools for materials engineering in nano science and technology. There is an inter-tube interaction at bundled structure that changes its physical properties.
    Keywords: Physical property, Density function theory, SiC nanotube, Ribbon, Semiconductor, Density of state, PWSCF, Simulation