Advanced Materials Research Vol. 1088

Abstract: Cd₂Ge₂O₆ nanowires have been synthesized via a simple and facile hydrothermal route using GeO₂ and CdO as the source materials with the surfactant. The structure and morphology of the Cd₂Ge₂O₆ nanowires were fully analyzed by field emission scanning electron microscope (FESEM) and HRTEM. With a focused electron beam irradiation, the Cd₂Ge₂O₆ nanowire became unstable and tended to heavily destroyed under a long time irradiation. Using the TEM-STM holder, electrical properties of an individual Cd₂Ge₂O₆ nanowire has been measured and the obtained I-V curve demonstrated the semiconductor property.

Abstract: The effects of different proportions of poly (vinyl alcohol) and polyamide 6 on the structure and property of electrospun PA6/PVA membranes have been studied. According to a certain proportion, PVA and PA6 were dissolved in formic acid. The solution was electrospun at 70 kV. The nanofibers membranes were characterized by SEM, FT-IR, XRD, TGA and DSC analyses. The sound absorption coefficients of each absorber are measured with SW477 impedance tube. PA6/PVA composite mats with good compatibility and relatively stable performance, and enhanced sound absorption and property may have many other important applications.

Abstract: In this study, Y₂O₃ microspheres have been selectively prepared by solvothermal method, without using any template and catalyst carrier. Based on the systematic analysis of the samples, we have discussed the effects of the thermal treatment temperature on the structure of the Y₂O₃ microspheres. Besides, we have also investigated the effect of microstructure on the photoluminescence properties of the phosphor, and the impact of rare earth ion doping concentration on the emission intensity of the phosphor. Powder X-ray diffraction analysis of the powders confirmed the formation of cubic Y₂O₃. Scanning electron microscope observation reveals that the as-synthesized powders are spherical particles of diameter of approximately 3 μm at 180 °C. Photoluminescence measurements indicate that the phosphor exhibits strongest emission peak at 612 nm, corresponding to the ⁵D₀-⁷F₂ electric-dipole transition. In addition, highest luminescence efficiency was observed in the phosphor with the rare earth ion doping concentration of 5%.

Abstract: Antibacterial potential of metallic silver nanoparticles (AgNPs) is considered to be influenced by their size and stability. In this study, the stable AgNPs capped with poly (4-styrenesulfonic acid-co-maleic acid) or PSSMA were successfully synthesized by using a chemical reduction method. The PSSMA-stabilized AgNPs (PSSMA-AgNPs) were characterized and tested for antibacterial activity against eight bacterial strains. Transmission electron microscopic studies showed that PSSMA-AgNPs were monodisperse spherical particles with an average size of 5.21 nm. From bacterial growth curve studies, PSSMA-AgNPs exhibited an antibacterial effect on Gram-positive bacteria (Staphylococcus aureus ATCC 25923, Staphylococcus aureus ATCC 6538p, Staphylococcus aureus ATCC 43300, Staphylococcus epidermidis ATCC 12228 and Bacillus subtilis ATCC 6633) and Gram-negative bacteria (Escherichia coli ATCC 25922, Enterobacter aerogenes ATCC 13048 and Pseudomonas aeruginosa ATCC 27853). Moreover, the Gram-negative bacteria were found to be more susceptible to the AgNPs.

Abstract: SiO₂/PI composite films with different percentage of incorporated nanoSiO₂ were synthesized. With the increase of the adding SiO₂ content, the surface roughness and the fractal dimension increased by SEM characterization for the fracture surface, and the thermal property of SiO₂/PI composite films improved. The results indicate that the degree of imidization of the polyimide was full, and the polymer structure transformed from disorder into order after SiO₂ was added to the PI matrix.

Abstract: Self-propagating exothermic formation reactions have been intensively studied in a variety of reactive multilayer films, which typically include alternating layers of two or more reactants. Here, we introduce a reactive multilayer film which contains a thermite reaction between Ni and Al.Al/Ni multilayer films which were composed of alternate Al and Ni layers were prepared by DC magnetron sputtering.The total thickness of each films was approximately 1.2 μm having bilayer thicknesses of 60, 100, 150 nm. Each bilayer consisted of an aluminum layer and a nickel layer in a 3:2 thickness ratio to maintain an overall 1:1 atomic composition.Meanwhile, Al/Ni multilayer films with the bilayer thickness of 60 nmwas prepared. In each bilayer, the thickness ratio of Al to Ni was maintained at 1:2 to obtain an overall 1:3 atomic composition.The total thickness of Al/Ni multilayer films was around 1.2 μm.DSC curves show that the values of heat release in Al/Ni multilayer films with bilayer thicknesses of 60 (Al:Ni), 100 (Al:Ni), 150 (Al:Ni) and 60 (Al:3Ni) nm are 324.63 Jžg^-1, 348.51 Jžg^-1, 400.45 Jžg^-1 and 69.85 Jžg^-1, respectively. XRD measurements show that the final products of exothermic reactions with Al:Ni atomic ratio of 1:1 and 1:3 are the compound of AlNi and AlNi₃, respectively.

Abstract: Thin SiO₂ZrO₂ films were prepared, up to 0.2 μm thick, by means of the sol–gel technology and characterized by a Scanning electron microscopy and X-ray diffraction. It is shown the presence of monoclinic, cubic and tetragonal phases of ZrO₂ in the SiO₂ matrix. The crystallites sizes depend on the annealing temperature of the film and amount to 35 and 56 nm for the films annealed at 773 and 973 K, respectively. The films resistance is rather sensitive to the presence of NO₂ and O₃ impurity in air at lower operating temperatures in the range of 30-60°C.

Abstract: Cd_1-xZn_xS thin films were grown on soda-lime glass substrates by chemical-bath deposition (CBD). The surface morphology, thickness, composition, state of the constituent elements and optical properties of the films were studied with X-ray diffraction (XRD), scanning electron microscopy (SEM), step height measurement instrument, X-ray photoelectron spectroscopy (XPS) and spectrophotometer, respectively. The affect of annealing for the Cd_1-xZn_xS thin films was studied. The Cd_1-xZn_xS thin films had cubic crystal structure and the average transmittance was 86.8% in the visible range with the optical band gap of 2.61eV and the films thickness was about 50nm. The atomic ratio of (Cd + Zn): S increased after annealing.

Abstract: This article presents a simple method for fabrication of Au-CdS composite thin films onto indium-tin-oxide (ITO) coated glass substrates. The method starts with electrodeposition of CdS thin films onto ITO substrates and followed by spontaneous growth of Au nanoparticles onto the CdS surface in solutions containing AuCl₄^- ions. X-ray diffraction (XRD) and UV-vis spectroscopy were used to investigate the Au-CdS thin films. The photoelectrochemical property and sensing for Hg²⁺ ions of the Au-CdS/ITO were studied. The electrode exhibits a low limit of detection of 2.5 μM and a high selectivity for Hg²⁺ ions, even in the presence of a large excess (1000-fold) of other metal (Na⁺, K⁺, Ca²⁺, Mg²⁺, Cd²⁺, Pb²⁺, and Zn²⁺) ions.

Abstract: A series of clay-based nanocomposite films were prepared by casting aqueous dispersions of exfoliated montmorillonite clay mixed with various loadings of water-soluble organic polymer. The clay films with a nacre-mimicking structure exhibited excellent flexibility and optical transparency even for high clay content (93 wt%).