Advanced Materials Research Vol. 549

Abstract: The Cu thin films were deposited on P type Si (111) substrates by ionized cluster beam (ICB) technique. The surface properties and atomic binding energy of Cu thin films were studied by X-ray Photoelectron Spectroscopy (XPS). The results show that for all XPS spectra of Cu/SiO₂/Si (111) samples deposited by neutral cluster and ionized cluster beam (V_a=5 kV), the atomic binding energy of the films was no differences with bulk materials. The reason may be that the local energy deposition and atomic restructuring caused by surface treatment process resulting in the XPS spectra of the copper films was similar with bulk standard copper.

Abstract: The effect of bath temperature on the morphologies, crystallographic structure and adhesive strength of TiO₂ nanotube arrays fabricated by electrochemical anodization of titanium in dimethyl sulfoxide containing hydrofluoric acid electrolyte were studied in this paper. The results show that the crystalline anatase TiO₂ nanotube arrays can be directly fabricated at the bath temperature above 50oC without further annealing. The crystallinity of anatase at the top of nanotubes is higher than that at the bottom of nanotubes. The bath temperature has obviously impact on the surface morphology of the titanium substrate underneath the nanotube arrays. The adhesive strength of TiO₂ nanotube arrays increases with the rise of bath temperature increasing, and reaches 11.3 MPa when TiO₂ nanotube arrays are fabricated at 60 oC.

Abstract: LDPE-g-MAH copolymer is prepared through reactive extrusion, and then added to LDPE/wood flour (WF) composites. Effects of LDPE-g-MAH and WF content on mechanical and rheological properties of LDPE/WF composites were investigated by melt flow rate (MFR), mechanical testing and advanced rheometric expansion system (ARES). Results show that the tensile strength of the composites increase with the increase of WF content, but the MFR value and elongation at break decrease tremendously. The tensile strength, impact strength, complex modulus and viscosity of the composites all show an increase with the application of LDPE-g-MAH on account of the enhanced interfacial adhesion. The abrupt ascent in the complex modulus of the LDPE/WF (70/30) composite when the shear rate reaches a definite value may denote changes in the aggregation structure of WF in LDPE matrix.

Abstract: The catalytic properties of nano-TiO₂ modified fabric suits the demand for self-cleaning in recent years. In this paper, advanced and innovative technology were used to synthesize water sol of titanium dioxide photocatalyst with high catalytic activity for fabric finishing. The wear behavior, antibacterial property and water repellency of treated and untreated fabric were tested. Results indicate that finishing and washing of the titanium dioxide had no effect on wear behavior; finished and washed fabric has a certain antibacterial and water repellent properties.

Abstract: FGD gypsum, fly ash and wheat straw are taken as main raw materials; waterproof agent, water reducer, activator and composite retarder are chosen as admixtures, and wheat straw reinforced desulfurization gypsum block is produced through reasonable processing technology. Block ratios of material, processing technology and performance are analyzed.

Abstract: Foam concrete samples with different density were prepared by physical and chemical foaming method respectively, and the demoulding time, 24h water absorption, mechanical properties and internal bubble holes structure of physical and chemical foaming samples were determined and compared. The result showed that the lowest dry density of physical foaming samples could only reach about 280 kg/m3, or there would be bubble collapse phenomenon after samples moulded; When samples dry density were about the same, compared with chemical foaming samples, physical foaming samples had longer demoulding time, significantly lower 24h water absorption, higher 3 days compressive and flexural strength and much better internal bubble holes structure.

Abstract: The melting temperature-pressure phase diagram [T_m(P)-P] for corundum (Al₂O₃) is predicted through the Clapeyron equation where the pressure-dependent volume difference is modeled by introducing the effect of surface stress induced pressure. Al₂O₃ has been employed to test the reliability of the model, because of its important role. Al₂O₃ has been extensively investigated because of its widely ranging industrial applications. This includes applications as a refractory material both of high hardness and stability up to high temperatures, as a support matrix in catalysis.

Abstract: (Bi_2-xLi_x) (Mg_2/3Nb_1.1833Sn_0.15)O₇ piezoelectric ceramics were prepared by conventional solid state reaction method. The microstructure and dielectric properties of dielectric ceramics were studied which was doped by different amount of Li₂CO₃. The experiment results showed that the density of the ceramics would decrease, but have little effect on the microstructure of the ceramics when the amount of the Li₂CO₃ doped increases. With the increasing of Li₂CO₃ doped, the dielectric constant(ε_r) and dielectric loss(tanδ) of dielectric ceramics first decreases and then increases. When tested in 1MHz frequency, the piezoelectric ceramics display the optimum properties tanδ is 0.00009, ε_r is 163 while Li₂CO₃ doped amount is 0.05 mol%.

Abstract: The corrosion behaviour on 20A carbon steel and 316SS in cooling water were studied through weight-loss measurements in different concentration ratio condition. The results obtained from this study showed that inhibitors played obviously effective role for 20A material, while inhibitors had no any positive effect to 316SS material; and concentration ratio 3~7 range was suitable for protecting both 20A and 316SS materials in power plant.

Abstract: The influence of hydrogenation on microstructure and tensile properties of Ti40 alloy has been investigated. The microstructure observation reveals that a new phase called η phase with FCC structure appears at the grainboundaries when the hydrogen content above 0.3 wt.%. With increasing hydrogen contents, the strength first increases and then decreases, and the ductility decreases as the specimens tensioned at both room temperature and 700oC. These phenomenons are resulted from the solution strengthening of hydrogen addition in Ti40 alloy with single β phase. As the hydrogen content increases, the fracture mode changes from dimple to cleavage fracture for specimens tensioned at room temperature. When tested at 700oC, the morphology of fracture surfaces in the specimens are all characterized by polygonal grains and the fractograph exhibits typically “sugar candy” brittle fracture for the specimen with 0.5wt% H.