Journal of Nano Structures
Volume:3 Issue: 2, Spring 2013

In this paper, the interaction between an oscillating dipole moment and a Silver nanoparticle has been studied. Our calculations are based on Mie scattering theory and discrete dipole approximation(DDA) method.At first, the resonance frequency due to excitingthe localized surface plasmons has been obtained using Mie scattering theory and then by exciting a dipole moment in theclose proximity of the nanoparticle, the induced charge distribution on the nanoparticle surface has been calculated. In ourcalculations, we have exploited the experimental data obtained by Johnson and Christy for dielectric function.

A new hybrid nanomaterial was developed by immobilization of phosphomolybdate anions on the surface of modified magnetite nanoparticles with quaternary phosphonium cations. Silica coated magnetic nanoparticles supported phosphonium cations, Ph3P+- SCMNPs, were prepared by covalent attachment of chloropropylsilyl groups on the surface of silica coated magnetite nanoparticles and next reaction with triphenylphosphine. Then, reaction of the prepared Ph3P+-SCMNPs nanomaterial with H3PMo12O40 resulted in the preparation of PMo-Ph3P+-SCMNPs hybrid nanomaterial. The PMo-Ph3P+-SCMNPs hybrid nanomaterial was characterized with different physicochemical methods such as FT-IR and ICP-AES spectroscopies, XRD, VSM, SEM, and TEM analyses. VSM analysis showed superparamagnetic properties of the prepared nanomaterial. TEM and SEM analyses indicated the aggregated nanoparticles with about 15 nm average size.

In this investigation, CuInS2 ternary compound was synthesized by injection of thiourea solution into a hot copper-indium solution. The CuCl, InCl3 along with (SC (NH2)2) were used as a precursor dissolved in high boiling point solvent such as oleylamine (CH(CH2)17NH2) and oleic acid (CH(CH2)16COOH) as a coordination solvent and capping agent, respectively. The size, distribution and shape were optimized by controlling some parameters such as the ratio of solvent to capping agent, anion and cation solution temperature in the instant of injection. The crystal structure, morphology, and optical properties of synthesized nanoparticles were characterized using XRD, TEM, UV-VIS-NIR and PL. The results indicatethat the temperature of the solution in the instant of injection has a significant effect on the tuning of the nanocrystals size as well as narrow size distribution.

Magnetic CuFe2O4 nanoparticles were synthesized by a facile microwave-assisted reaction between Cu(NO3)2 and Fe(NO3)3. The magnetic nanoparticles were added to starch to make magnetic polymeric nanocomposite. The nanoparticles and nanocomposites were characterized using X-ray diffraction and scanning electron microscopy. The magnetic properties of the samples were investigated using an alternating gradient force magnetometer (AGFM). The copper ferrite nanoparticles exhibited ferromagnetic behavior at room temperature, with a saturation magnetization of 29emu/g and a coercivity of 136 Oe. The distribution of the CuFe2O4 nanoparticles into the polymeric matrixes decreases the coercivity (136 Oe to 66 Oe). The maximum coercivity of 82 Oe was found for 15% of CuFe2O4 distributed to the starch matrix.

In this study, forced-vibration analysis of a coupled system of single layered graphene sheets (SLGSs) subjected to the moving nano-particle is carried out based on nonlocal elasticity theory of orthotropic plate. Two SLGSs are coupled with elastic medium which is simulated by Pasternak and Visco-Pasternak models. Using Hamilton’s principle, governing differential equations of motion are derived and solved analytically. The effects of small scale, aspect ratio, velocity of nanoparticle, time parameter, mechanical properties of graphene sheets, Visco-elastic medium on the maximum dynamic responses of each SLGSs are studied. Results indicate that, if the medium (elastic or visco-elastic medium) of coupled system becomes more rigid, the maximum dynamic displacements of both SLGSs will be closer together.

The silica aerogel was prepared by the acid–base sol–gel polymerization of tetraethylorthosilicate precursor followed by ambient pressure drying. The prepared silica aerogels were characterized by Fourier transform infrared (FT-IR), Thermogravimetric and differential thermal analysis (TG/DTA), X-ray diffractometer (XRD), Energy dispersive X-ray microanalysis (EDX), Brunauer–Emmitt–Teller (BET) and Scanning electron microscopy (SEM). The result silica aerogel is a light and crack-free solid with very low bulk density 0.027 g /cm3, high specific surface area 655.58 m2/ g and large pore volume 0.4831 cm3/ g. The average size of particles was calculated using a Microstructure Measurement program and Minitab statistical software.

In this investigation, a facile and green sonochemical route has been developed for the synthesis of 2-Ketomethylquinolines by using 2- methylquinolines and several acyl chlorides in the presence of nanocrystalline MgAl2O4 as an efficient heterogeneous catalyst. The combination of nanocatalyst and ultrasonic process afforded corresponding ketomethyl quinolines in shorter reaction durations, and in high yields. This work consistently has the advantages of excellent yields, short reaction time, mild condition and work-up procedures. This method might be useful in the future for the preparation of similar derivatives.

In this paper, the mer-Co(NH3)3(NO2)3 complex was used as a new precursor for synthesizing spinel-type cobalt oxide nanoparticles (Co3O4NPs).Thermal decomposition of the complex at low temperature (175 °C) resulted in the Co3O4NPs without using expensive and toxic solvents or complicated equipment. XRD, FT-IR, SEM, EDX, and TEM were employed to characterize the product, and its optical and magnetic properties were studied by UV-visible spectroscopy and a VSM, respectively. FT-IR, XRD and EDS analyses confirmed the formation of single-phase Co3O4 with cubic structure. The lattice constant calculated from XRD peaks is 8.0650 Å. SEM and TEM images showed that Co3O4NPs have a sphere-like morphology with an average size of 19 nm. Optical spectrum of Co3O4NPs revealed the presence of two band gaps at 2.20 and 3.45 eV values, which in turn confirmed the semiconducting properties. The magnetic measurement of Co3O4NPs showed a weak ferromagnetic order at room temperature.

Current article describes application of zeolites in fluid catalytic cracking (FCC). The use of several zeolitic additives for the production light olefins and reduction of pollutants is described. Application of zeolites as fluid catalytic cracking (FCC) catalysts and additives due to the presence of active acid sites in the zeolite framework increase the formation of desired cracking products (i.e., olefin and branched products) in the FCC unit.

Applying Nanoporous Materials is an appropriate method for improving chemical quality of the water due to high surface area, internal porous structure (porosity), high absorption capability of harmful gases and liquids, and capability of reactivating the surface. Therefore, actions were carried out in order to investigate the effect of Activated carbon and Zeolite on reducing the total dissolved solids in water to perform experiment in a randomized complete block design with four treatments and three replications in greenhouse. Results indicated that there are significant differences among various treatments of water in terms of change in the concentrations of chemical elements in water. Subsequently, we measured some traits in plant samples in order to evaluate the reaction of the radish plant related to changes in water quality resulting from use of these absorbers. Other characteristics did not show remarkable differences with the control sample based on the results of variance analysis related to plant samples with the exception of shoot’s chloride.

ZnO nanorods and nanoparticles have been easily prepared via the decomposition of two simple Schiff base zinc (II) complexes, namely (N,N'–disalicylalethylenediamine)zince(II) and (N,N'– disalicylalphenylenediamine)zince(II) under microwave irradiation. The decomposition products of the complexes were characterized by FT-IR, XRD, SEM, EDX and UV-visible spectroscopy. FT-IR, XRDand EDX results confirmed that as-prepared products are pure and single-phase ZnO. SEM images show that the product of each complex was made up of ZnO nanoparticles average diameter size of 50 nm and ZnO nanorods with diameter of 70–100 nm and length up to 3.5 μm. ZnO nanostructures prepared by present method could be appropriate photocatalytic materials due to a red shift in their band gaps (2.80 and 2.95 eV) compared with the bulk sample (3.37 eV). This method is simple, fast, safe, low-cost and also it is suitable for large-scale preparation of high purity ZnO nanostructures for applied purposes.

Titanium nitride-Copper (TiN-Cu) nanocomposite films were deposited onto stainless steel substrate using hollow cathode discharge ion plating technique. The influence of Cu content in the range of 2-7 at.% on the microstructure, morphology and mechanical properties of deposited films were investigated. Structural properties of the films were studied by X-ray diffraction pattern. Topographyof the deposited films was studied using atomic force microscopy. Film hardness was estimated by a triboscope nanoindentation system. However, X-ray photoelectron spectroscopy analysis was performed to study the surface chemical bonding states. It was found that addition of soft Cu phase above 2 at.% to TiN film drastically decreased the film hardness from 30 to 2.8 Gpa due to lubricanteffect of segregated copper particles. X-ray photoelectron spectroscopy results showed that Cu and TiN phases grew separately. In our case,the formation of a solid solution or chemical bonding between Cu and Ti was rejected.

A graphene nanosheets (GNS) film coated glassy carbon electrode (GCE) was fabricated for sensitive determination of tyrosine (Tyr). The GNS-based sensor was characterized by scanning electronmicroscope and electrochemical impedance spectroscopy. The voltammetric techniques were employed to study electro-oxidation of Tyr. The results revealed that the modified electrode showed an electrocatalytic activity toward the anodic oxidation of Tyr by a marked enhancement in the current intensity and the shift in the oxidation potential to lower values (50 mV) in comparison with the bare GCE. Some kinetic parameters such as the electron transfer coefficient (α) were also determined for the Tyr oxidation. The detection limit for Tyr was found to be 2.0×10-8 M (n=9), and the peak current increases linearly with the Tyr concentration within the molar concentration ranges of 5.0 ×10-6 to 1.2 ×10-4 M. The modified electrode shows good sensitivity, selectivity and stability. The prepared electrode was applied for the determination of Tyr in real sample.