Advanced Materials Research Vol. 486

Abstract: Fully amorphous Zr₄₈Cu_43-xAl₇Ag₂Ni_x(x=0, 2, 4, 6, 8 at. %) alloy system synthesized by Cu mould casting method were utilized to study corrosion behavior due to the poor corrosion resistance of Zr-Cu-Al-Ag alloy system by addition of Ni. High temperature DSC revealed that the Zr-based alloy system still maintained good glass-forming ability and thermal stability with the addition of Ni element. The result obtained from both the immersion test and the potentiodynamic polarization test showed that the addition of Ni element significantly improved the corrosion resistance compared to the Ni-free Zr-based alloy system. SEM graph showed a phenomenon of corrosive pit where there existed corrosion deposits as well as cellular textures and microcracks. In summary, proper addition of Ni could modify the corrosion resistance of the Zr-based alloy system.

Abstract: A new catalytic route was reported for the epoxidation of soybean oil (SBO) with tert-butyl hydroperoxide (TBHP, 65 wt. %) as the clean oxidant over manganese (III) tetraphenylporphyrin chloride (Mn (TPP) Cl) catalyst without carboxylic acid. Effect of tetraphenylporphyrin chloride with various metals (Mn, Fe, Co, Ni and Zn) on SBO epoxidation has been investigated. As biomimetic catalysts, the optimum reaction temperature of the system existed for catalytic activity, which was about 40 °C. The optimum reaction time was 6 h and the suitable promoter was pyrrole considering various factors. The suitable oxidant was TBHP of 65 wt. %. A mechanism for SBO epoxidation was discussed, and a role for high-valent metal peroxide intermediate with double bond directly as part of this mechanism was proposed, which was verified by in situ UV-Vis spectroscopy. The optimized reaction conditions were acquired.

Abstract: In order to manufacture a three dimensional sheet metal part effectively, a continuous sheet metal forming process (CSMF) based on flexible roll bending has been proposed and developed. This paper mainly focuses on the fundamental aspects of the process, the principle of CSMF is introduced and the method to estimate the downward displacement of upper roll based on the desired curvature of the deformed sheet metal is presented. The variation of the upper rolls downward displacement with the desired bend radius is shown in graphically. The smoothness of the CSMF parts was measured and analyzed. In the results, it is shown that a three-dimensional sheet metal part can be formed without defects and the formed surfaces are in good agreement with the target shapes.

Abstract: This paper describes microstructure and optical characteristics of ZnO-doped CeO₂ thin films were deposited by sol-gel method with various preheating and annealing temperatures. Particular attention will be paid to the effects of an annealing treatment in air ambient on the physical properties. The deposited films were characterized using X-ray diffraction. The surface morphologies of annealed film were examined by scanning electron microscopy. Optical properties of the ZnO-doped CeO₂ thin films were obtained by UV-visible recording spectrophotometer. The dependence of the optical properties and microstructure characteristics on thermal treatment was also investigated.

Abstract: Microstructure, optical and electrical properties of ZnO-doped (Zr_0.8Sn_0.2)TiO₄ thin films prepared by rf magnetron sputtering on ITO/Glass substrates at different argon-oxygen (Ar/O₂) mixture have been investigated. The surface structural and morphological characteristics analyzed by X-ray diffraction (XRD) and atomic force microscope (AFM) were found to be sensitive to the Ar/O₂ ratio. Optical transmittance spectroscopy further revealed high transparency (over 70%) in the visible region of the spectrum. At an Ar/O₂ ratio of 100/0 and a substrate temperature of 400°C, the ZnO-doped (Zr_0.8Sn_0.2)TiO₂ films possess a dielectric constant of 44 at 10 MHz, a dissipation factor of 0.03 at 10 MHz, a leakage current density of 3.73×10^-9 A/cm².

Abstract: This research analyzes the microstructure of hardened blended cement pastes. Fly ash was used to replace Portland cement type I paste. Test results indicated that hardened blended cement paste were significantly affected by duration after mixing. The X-ray diffraction (XRD) and the scanning electron microscope (SEM) showed changes of microstructure by duration.

Abstract: In order to enhance the re-collecting ability of Cu₂O, Cu₂O/NiFe₂O₄ magnetic complex was synthesized in this paper. XRD patterns showed the prepared material was the complex of Cu₂O and NiFe₂O₄. The saturation magnetization (Ms) of Cu₂O/NiFe₂O₄ magnetic complex was 12.056emu/g. The Cu₂O/NiFe₂O₄ magnetic complex was used for the decolorization of P-nitrophenol solution in a photocatalytic degradation reactor under the visible light irradiation. In this work, the Cu₂O/NiFe₂O₄ magnetic complex is recycled for 3 times, and the decomposition rates are all above 60%. The XRD also showed that the Cu₂O/NiFe₂O₄ complex was neither oxidized nor deoxidized in the photocatalytic degradation process. It can be concluded that the prepared Cu₂O/NiFe₂O₄ complex can be recycled applied to photocatalytic degradation treatment.

Abstract: The paper pulp compression molding material is one of the most commonly used materials in packing industry. Their mechanical properties attract attentions from professional visitors and researchers. It is a difficult work to test the mechanical properties as the paper pulps are thin, anisotropic and sometimes wet. To spray ink spots with the surface of the specimens is not allowed either. The digit image frequency correlation method (DIFC) is presented in the paper, the information carrier of the displacement is the nature texture on the tested surface. Image acquiring and analysis are accomplished by the CCD camera and computer. From the displacement field strain distributions were obtained and the mechanical properties of the paper pulp compression molding material were evaluated. The test system is simple and the sensitivity is adjustable. DIFC is approved a suitable test method for paper pulp compression molding material.

Abstract: In this paper, nanotubular TiO₂ obtained by hydrothermal method was selected as precursor to prepare metal ion decorated TiO_2-xN_x via a facile and one-pot method. As-synthesized M/TiO_2-xN_x (M references to Pd, Fe, Ni, Li) photocatalysts were characterized by means of X-ray diffraction, diffuse reflectance spectrometry, fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. The photocatalytic activities of different metal ion decorated TiO_2-xN_x samples were compared by monitoring the photocatalytic oxidation of propylene under both ultraviolet light (UV) and visible light (Vis) irradiation. It was found that Pd/TiO_2-xN_x sample possessed the highest photocatalytic activity under both UV and Vis irradiation. The better crystallinity, better visible light absorption, higher hydroxy concentration were contributed to the best photocatalytic performance of Pd/TiO_2-xN_x.

Abstract: The PLA-PEG block polymer was prepared by opening ring polymerization catalyzed by solid super acid SO₄^2-/ZrO₂-CeO₂. The acidic property was measured by IR spectra, Hammett Indicator and NH₃-TPD techniques. The copolymer was measured by FTIR spectra. The results show the solid super acid SO₄^2-/ZrO₂-CeO₂ had the strongest acid strength and maximal acid content roasted at 650. Under reaction conditions which were the amount of catalyst 1.0% vs lactide, and polymerization at 170 for 9 h, the intrinsic viscosity reached 1.562 dl^. g^-1.