Advanced Materials Research Vol. 646

Abstract: The vapor transport method was used to grow ZnO nanowires on ZnO:Al (AZO) deposited silicon substrate. The optimal characteristic of ZnO nanowires was grown at 1100°C for 70 min, together with a ZnO/graphite weight ratio of 1:1 and N2/O2 flow ratio of 7:6. ZnO nanowires had a single crystalline structure and grew with a prefer direction in the (002) plane. Photoluminescence measurement showed that UV and visible green emission bands were observed. The turn-on electric field of ZnO nanowires was 0.11 V/μm and the maximum field emission current density was 1.8 mA/cm2. A high field enhancement factor of 1782 was evaluated.

Abstract: A comparative evaluation of three different methods for fabrication of SiO2/epoxy nanocomposite was investigated. The methods evaluated in this study were mechanical blending, traditional sol-gel approach and novel microemulsion polymerization. The nanocomposites were characterized by tensile tests and SEM studies. It was found that microemulsion polymerization is a more satisfying method for generation of epoxy-based nanocomposites.

Abstract: We studied the effect ofthe magnetoelastic ansitropy on properties of nanostructured glass-coated microwires with soft magnetic behaviour (Finemet-type microwires of Fe70.8Cu1Nb3.1Si14.5B10.6, Fe71.8Cu1Nb3.1Si15B9.1 and Fe73.8Cu1Nb3.1Si13B9.1 compositions) and with granular structure (Cu based Co-Cu microwires). The magnetoelastic energy originated from the difference in thermal expansion coefficients of the glass and metallic alloy during the microwires fabrication, affected the hysteresis loops, coercivity and heat capacity of Finemet-type microwires. Hysteresis loops of all as-prepared microwires showed rectangular shape, typical for Fe-rich microwires. As expected, coercivity, HC, of as-prepared microwires increases with decreasing of the ratio ρ defined as the ratio between the metallic nucleus diameter, d to total microwire diameter, D. On the other hand we observed change of heat capacity in microwires with different ratio ρ. In the case of Co-Cu microwires ρ- ratio affected the structure and the giant magneto-resistance of obtained microwires.

Abstract: Nanopore has the proming to be used as the detection senser for the single molecule at single molecular level or the nanoparticles in different meterials. The diameters of the nanopores can be changed in a large rang with the increasing fabrication technology. For this case, the nanopore could be used as particles‘ sizes senser. We used 15nm gold nanoparticles as exsamples to analyze the effects of nanopore/nanoparticle ratio in deionized water. In the detection experiments, we found that the gold nanoparticles would pass through the nanopore in different behaves. Besides, the diameters of the nanopores might effect the precision accuracy of the translocation events. In view of the former results, we notice that on the basis of nanopore detection technique, nanoparticles translocation share many similarities with DNA.

Abstract: Silver nanostructures were synthesized by a template wetting method throughout decomposition of silver acetate. The morphology and activation energy of silver nanostructures were investigated. The activation energy from silver acetate to silver particles can be evaluated by Friedman method, which is dependent of the decomposition process, and the activation energy was estimated in the range between 355 and 400 kJ/mol. The template wetting method utilizing the decomposition of silver acetate can be applied to produce a silver nanostructured material with high functional properties.

Abstract: This paper describes the preparation and characterization of nanocrystalline Magnesium Oxide (MgO) using sol-gel technique for optical applications. The prepared nanocrystalline MgO was chemically homogeneous, very pure and specifically hydroxylated and was characterized by standard techniques. The size of the prepared nanoparticle was found to be 27.38 nm ± 0.65 nm and exhibited a face centered–cubic structure and exhibited two lifetimes viz., 1 = 0.24 ns and 2 = 8.9 ns. Its binding energy was found to be 50.9 eV, which showed the formation of single phase MgO on the surface. It behaved as semiconductor over the temperature range of 500 °C to 660 °C and as perfect insulator in the temperature range 100 °K to 300 °K.

Abstract: Nanoporous anodic aluminum oxide (AAO) templates are fabricated using an anodization method. The mean diameters of nanoporous anodic aluminum oxide templates are 100 nm and 200 nm by various processing parameters of the anodization method. A molded plastic thin film nanostructure is fabricated by nanoimprinting using the AAO template as a mold. The surface properties of the molded plastic thin film are discussed using various nanoimprinting process parameters. Contact angles of the molded plastic thin film with the nanostructure exceed those without the nanostructure. The molded plastic thin films with a nanostructure and a hydrophobic surface are formed, and their contact angles exceed 90°.

Abstract: Two Nano Hydrated Lime (NHL) materials with particle sizes of 50 nm and 100 nm were used in this study to investigate to the effect of NHL modification on the creep and recovery of Warm Mix Asphalt (WMA) binders foamed using Advera® with respective to rutting. The NHL was added to the asphalt binder at ratios of 20%, 10%, and 5% by weight of the asphalt binder. The creep and recovery tests were performed at three different stress levels, 3Pa (creep for 100 sec. and 600 sec. recovery), 10Pa (creep for 20 sec. and 600 sec. recovery), and 50Pa (creep for 1 sec and 300 sec. recovery). The tests were performed at a temperature of 58oC. The results were also compared with the Regular Hydrated Lime (RHL) results. The overall results reveal that the neat asphalt binders foamed using advera® showed larger permanent deformation (rutting) potential compared to the binder modified with RHL and NHL foamed using Advera®. As the NHL dose increases, the non-recoverable compliance decreases (rutting decreases). It was also concluded that the application of the RHL with the normal dose (20% by weight of binder) can be replaced by adding 5% (by weight of binder) of 50 nm NHL with respective to rutting.

Abstract: Fine dispersion of graphenes is crucial for the application of graphenein various fields. However, graphenes are frequently aggregated due to the large surface area and van der Waals interactions between themselves during the mixing process. Thus, various modifications of graphenes are necessary for the fine dispersion. Introduction of functional groups into graphenes accompanies loss of inherent advantages. In this study, introduction of silver nanoparticles into graphenes by in situ process was investigated. Especially, microwave irradiation was employed for the syntheses sincegraphenes absorb microwave efficiently and became heated quickly. Formation of silver nanoparticles on the grapheneafter microwave irradiation was confirmed and the average diameter of the silver nanoparticles in the hybrids was about 30 nm. Rheological and electrical properties of the epoxy resins filled with the hybrids are discussed in this report.

Abstract: This paper mainly studies on the morphologies of Platinum(Pt) nanoparticles decorated on polyanilene(PANI)and their influence on the sensitivity of glucose biosensor. Seldom researches were carried on the morphologies of Pt nanoparticles and the optimization of parameters. Compared by scanning electron microscopy(SEM), cyclic voltammetry(CV) and glucose current response, Pt completely wrapped PANI nanofibers shows better electrochemical stability, sensitivity and larger catalytic area than different kinds of Pt decorated PANI membranes. Pt completely wrapped PANI nanofibers are provided by electrochemical deposition Pt nanoparticles on PANI nanofibers under a special voltage. The average diameter of nanofibers which form porous Pt/PANI membrane is 100 nm. CVs of this membrane become stable in seven circles and provide a higher current peak which indicates larger catalytic area. The sensitivity indicated by current-time glucose response is several times of the other membranes.