International Journal of Nano Dimension
Volume:5 Issue: 2, Spring 2014

In this study, multi wall carbon nanotubes (MWCNTs) were synthesized by Chemical vapor deposition (CVD) method using two different catalysts (Fe nanoparticles) and (Ni nanoparticles) with two different substrates: Quartz and Alumina. Acetylene gas was used as a carbon source and Argon as a carrier gas at different temperatures and different times to study the effects of these parameters on CNTs yield. The produced MWCNTs were then purified by oxidation followed by chemical method involving treatment of MWCNTs with concentrated acids (H2SO4 and HNO3) to remove impurities. The MWCNTs were then functionalized by acidic treatment. The functionalized MWCNTs were then coated with Nickel using electroless plating method. Metal matrix composites (MMCs) were prepared by powder metallurgy method using Al/uncoated MWCNTs and Al/coated MWCNTs. The results show that the diameter range of prepared MWCNTs was (30-50) nm. The yield of CNTs using Ni nanoparticles as catalyst is higher than that of using Fe nanoparticles as catalyst. The coated CNTs have diameters ranging from 65-85 nm. The hardness of Al/coated CNTs composites is higher than that of Al/uncoated MWCNTs composites.

Core-shell 12-tungstophosphoric acid/TiO2 (HPW/TiO2) nanoparticles at 10 and 20% of HPW have been synthesized by simple in-situ sol- gel method. Characterization of the samples was carried out by X-ray diffraction (XRD), Scanning electron microscopy (SEM), Fourier transform infrared (FTIR). The X-ray diffraction patterns of as prepared solid samples, indicated characteristic peaks of titania with additional peaks concerning to HPW in a very low intensities. This result in addition to the FTIR and SEM - EDX analysis data confirmed incorporation of HPW / TiO2 nanostructure in spherical morphology with a particle size of around 25 nm.

In this study, TiO2 and ZnO nanofilms were prepared by sol-gel spin-coating method. Nanofilms were characterized by X-ray Diffraction (XRD), Energy Dispersive Analysis of X-ray (EDX), Scanning Electron Microscopy (SEM) and Field Emission Scanning Electron Microscopy (FE-ESM). Structural and morphological properties of nanofilms were investigated. The average crystalline size of TiO2 and ZnO nanoparticles which were obtained from the ignition of sols were obtained 80 and 50 nm, respectively. The morphological properties of nanofilms showed that the TiO2/ZnO nanocomposite film was strongly related to the steps of coating. Also, photocatalytic degradation of methylene blue on the surface of these nanofilms under UV light irradiation was studied and results were compared to each other.

We report on the synthesis, morphology, chemically and structurally of TiO2-NiO-SiO2 nanostructure. The TiO2-NiO-SiO2 nanostructure was synthesized by a method based on the sol-gel method, by the simultaneous gelation of all cations. The coatings were deposited on dried soda-lime glass slides by spin coating. Composite powders and coating on glass have been characterized by XRD, SEM, EDAX, and FTIR. X-ray diffraction showed the formation of nano crystalline, anatase, TiO, NiO and NiTiO3 phases. Scanning electron microscopy revealed that nanostructure formed by increasing the calcinations temperatures. EDX spectroscopy confirmed the composition of the ternary powders and coating, which were formed during the gelation process. The effects of chemical compositions and calcinations temperature on the surface topography and the crystallization of phases were studied. The activation energy (E) of nanoparticles formation during thermal treatment was calculated.

We will present a detailed investigation of intersubband transitions process in core-multi shells quantum dots. The confined wave functions and eigenenergies of electrons in quantum dots have been calculated under the effective-mass approximation by solving a three-dimensional Schrodinger equation. Excellent dependence is found between size effects, time relaxation and degenerate four wave mixing (DFWM). We found that the enhancement of the thickness layers lead to strongly enhancement in peak value of DFWM.

Metallic silver nanoparticles have been reduced from silver nitrate by employing the extracellular enzymatic machinery of edible White button Mushroom (Agaricus bisporus). The physical properties of these particles, size and shapes have been determined using techniques like TEM, FTIR and XRD and were reported in our earlier report. But, what stands of paramount importance in the present context is the ability of these nanoparticles to successfully combat and nullify the pathogenic fungal strains affecting crop plants. Our study has shown that these silver nanoparticles are successful antifungal agents and can replace the conventional antifungal synthetic chemicals as we tested their efficacy against different rot causative fungi in ground nut. The experimental pathogenic fungi include Stem rot causing diseases Sclerotium rolfsii, Dry root rot causing Rhizoctonia bataticola, Collar rot causing Aspergillus niger in agricultural plants.

ZnO and Mn-ZnO nano powders were prepared by the sol-gel auto combustion method. The products were characterized by X-ray diffraction (XRD), energy dispersive analysis of X-ray (EDX) and scanning electron microscopy (SEM). Structural and morphological properties of nano particles were investigated and the average crystalline size of ZnO and Mn-doped ZnO was obtained 44 and 51 nm, respectively. Also, photo catalytic removal of Cibacen Turquoise Blue G dye from aqueous solution by using nano scale ZnO and Mn-ZnO powders under UV light irradiation was studied. The effect of initial dye concentrations and dosage of photo catalysts, were investigated in the photo destructive process. This is 57% of dye degraded by 0.02 mg of ZnO in 70 minutes. The degradation rate increase to 84% in the presence of 0.02 mg of Mn-ZnO in the same time.

Silver is composed of a large percentage of silver oxide due to their large ratio of surface to bulk silver atoms. Silver nanoparticles have been a potent antibacterial, antifungal, anti-viral and anti-inflammatory agent. A simple, eco-friendly, inexpensive biosynthetic method was employed to synthesize silver nanoparticles. The present study aimed at the comparative study of silver nanoparticles synthesized through microbial and chemical methods. A microbial route to synthesize silver nanoparticles by Actinomycetes sp. was done. Actinomycetes are aerobic, Gram-positive bacteria, generally exhibiting branched filamentous growth and contain high guanine plus cytosine content in their DNA. Chemical methods were employed to synthesize silver nanoparticles. Chemical reduction of silver ions (Ag+) using sodium borohydride in aqueous solution generally yields silver nanoparticles with particle diameters of several nanometers. It is observed that reduction is slow in chemical methods as compared to rapid microbial synthesis of silver nanoparticles. The obtained silver nanoparticles were characterized using UV-vis spectroscopy and TEM. TEM images of microbially synthesized silver nanoparticles were of smaller size (10-20 nm) compared to chemical methods (60-80 nm). The microbially synthesized silver nanoparticles using Actinomycetes were found to be highly toxic to bacteria and it was found that smaller silver nanoparticles synthesized by microbial route had a greater antibacterial activity when compared to their chemical moieties.

In this research Calcium fluoride nanoparticles and its different amount of cerium ion dopant (5%and 10%) were prepared. The mentioned nanoparticle were studied by fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), absorption and photoluminescence spectra (PL) and Scanning electron microscopy (SEM). The XRD patterns indicate a typical cubic fluorite structure and no other impurities. SEM results show the synthesized particles having uniform grain size. Many absorption peaks and bands are present in the absorption spectra, corresponding to the rich energy levels of cerium ion.

In this paper, the adsorption of cerium on modified Mesoporous aluminosilicate (with Si/Al mole ratio of 10) was studied. The effects of pH, contact time, initial concentration of cerium on adsorption of cerium were investigated. The adsorption capacity was high in the pH range of 4-8 and decreases with decreasing of the pH value. The Langmuir and Freundlich isotherms were applied to represent the adsorption process. Both Langmuir and Freundlich isotherms fit the experimental data quite well. The Langmuir monolayer capacity of the adsorbent was 0.032 mmol.g-1.

This study is focused on synthesis of nano-colloidal silica via alkaline water glass solution. Sodium ions of water glass were removed by cation exchanging in a resin column to obtain the silicic acid which was titrated to the solution of sodium silicate. Concentration of the colloidal silica and pH value of the solutions were controlled using different concentrations of alkaline sodium silicate and silicic acid solutions in constant temperature and titration rate. The synthesized colloidal silica was characterized by Dynamic Light Scattering (DLS), Scanning Electron Microscopy (SEM), X-Ray powder Diffraction (XRD), Accelerated Surface Area and Porosimetry analyzer (ASAP) and Gravimetric method. The results showed that the average particle size of colloids and their stability were also influenced by various important factors such as pH, Temperature, Concentrations of alkaline sodium silicate and silicic acid solutions. The results showed that the synthesized nano-colloidal silica suspensions in concentration up to 25 wt.% of SiO2 with average particle sizes in range of 23 to100 nm are stable more than one year. Also, surface area and pore volume of the prepared spherical colloidal silica particles were160 m2/g and 0.27 cm2/g, respectively.

This paper investigates the effect of different methods of carbon nanotubes distribution in a thin matrix on static and dynamic behavior of the nanocomposite. Five different symmetric patterns of distribution are considered, including four parabolic patterns and a linear one. For each pattern, the effective mechanical properties of the resultant nanocomposite are calculated using the rule of mixture. Influence of geometric parameters on static and free vibration responses of the nanocomposite plate are studied. Finite element modeling is created using Abaqus/CAE. The resulting responses for linear distribution of nanotubes are compared to a past work and good agreement is observed between them. The finite element simulations showed that in all different cases of geometric parameters, the value of non-dimensional static deflection of the mid-point of plate under a uniformly distributed load is minimized in the linear distribution pattern of carbon nanotubes case and will increase by changing the pattern to a parabola. This fact is vice versa about modal analysis. Linear distribution pattern of carbon nanotubes results in higher natural frequencies in comparison with the parabolic distributions of carbon nanotubes.

Toxicity has occurred in workers exposed to nickel dust or nickel carbonyl formed in refining. Increased risk of nasal and lung cancers was linked to occupational nickel exposure before current workplace safety standards were set. Activated carbon with nano holes used for removing contaminants in environment. The purpose of this work is preparation a new nano-absorber, GZ-BAKI-TAC-Ni-88, for the adsorption of water soluble Nickel ions in polluted water. The adsorption capacity and the kinetic of maximum percent by metal concentrations in 50 and 100 and 150 ppm were studied. The amount of Nickel uptake was 52.0, 95.0 and 141.6, respectively. The maximum adsorption of Nickel achieved (q) 141.6 in 1200 minutes with 150ppm primary concentration of Nickel. Results indicate that the GZ-BAKI-TAC-Ni-88 with good absorbing water solution of Nickel separation and increasing Carbon Nano-holes and Active absorption of Sodium Alginate increased Nickel. According H-equation, the maximum adsorption of Nickel ions are calculated, the mg amount per gram absorber (TAC) is 55(mg/g) or 55000 ppm respectively. In comparison with published paper is highest capacity Ni, 17.21 mg/g or 17210ppm respectively. Kinetic adsorption of Ni indicated amount of 61.234%Ni occurs on 1320 min for Nickel. SEM images of this adsorber indicate the existence of micro and meso hole and occupation by Ni ions.