Advanced Materials Research Vol. 787

Abstract: A series of functionalized SBA-15 with various contents of titanium phosphates [TiPO-SBA-15(x)] have been successfully synthesized by a facile and effective method. The obtained products possess well ordered mesostructure, high surface area and large pore size. TEM and images show that mostly titanium phosphates species have deposited on the external surface of SBA-15. UV-Visible spectra, ³¹P MAS NMR and XPS indicate that the coordinated environment of Ti and P species in TiPO-SBA-15(x) is very similar to that of conventional amorphous titanium phosphates (TiPO). Very importantly, catalytic data in dehydration of cyclohexanol show that is more active than conventional titanium phosphates (TiPO), and their catalytic activities can be easily recovered. All these results indicate that TiPO-SBA-15(x) is a novel, active and recycled catalyst for dehydration of alcohols, which may be potentially useful heterogeneous catalysts in practical applications.

Abstract: The hot-dip galvanized and hot dip aluminized are widely used surface anti-corrosion technologies in steel beam guardrails region all over the world. Both of coating can not only play the role of landscaping, but also can protect the base metal from being eroded, and greatly extending the life of the guardrails. The appearance quality, process characteristics, corrosion resistance and cost of the two anti-corrosion coating are described in this paper. By analyzing both the similarities and differences between the two anti-corrosion technologies and their application advantages, we hope to provide some references on choosing the surface anti-corrosion technology.

Abstract: About 300nm-thick Ni₈₀Fe₂₀ films were deposited on SiO₂/Si (100) substrates at 300 K and 673 K in 1.2 Pa and 0.8 Pa Ar gas by a direct current (DC) magnetron sputtering system with the oblique target. The films grown at 300 K have a predominate [11 crystal orientation in the growth direction whereas those deposited at 673 K grow mainly with a [11 crystalline orientation in the growth direction. All the films have a columnar structure. The grain size increases with increasing deposition temperature. The films grown at 673 K are dense compared with those grown at 300 K. The film deposited at 673 K in 0.8 Pa Ar has the lowest resistivity.

Abstract: AISI 304L austenite stainless steel was irradiated by a high-current pulsed electron beam (HCPEB) source in different process. The microstructures were investigated in detail by electron microscopy. The changes of hardness and corrosion resistance induced by irradiation were also tested. The relationship between corrosion resistance and the microstructures has been explored. The experimental results demonstrate the potential of proper HCPEB processing for improving the hardness and corrosion resistance of metallic materials.

Abstract: Metamaterials are artificial materials engineered to have exotic properties that may not be found in nature, and it provides a novel tool to significantly enhance the sensitivity of sensors, and open new degrees of freedom in sensing design aspect. In this paper, a metamaterial sensor based on microstrip-line-excited SRR is developed, and its properties are analyzed in theory and simulated by full wave simulations. The results show good agreement with the theory. On this basis, single-channel sensor is extended to two channels and even four channels sensor. By observing and comparing the transmission profile by putting different sample on every channel, we found that the multi-channel sensor can work independently and posses good selectivity. Furthermore, the sensitivity of sensor will be greatly enhanced with the increase of SRR thicknesses. This work would pave a new way to design sensor with higher performance.

Abstract: The guanine as a corrosion inhibitor for copper in 0.5 mol/L sulfuric acid solution was investigated using weight loss experiment, polarization curves, AC impedance. The results showed that the inhibition performance of the guanine depended on the concentration of the inhibitor and the highest inhibition efficiency of the guanine reached 92.2% at 1×10^-3 mol/L in 0.5 mol/L sulfuric acid solution. The potentiodynamic polarization measurements showed that both cathodic and anodic processes of copper corrosion were suppressed and the guanine acts essentially as a mixed-type inhibitor. The results obtained from EIS measurements are in good agreement with that obtained from potentiodynamic polarization. The adsorption of the guanine is found to obey Langmuir adsorption isotherm and belong to physisorption.

Abstract: The microstructures and properties of 2024 aeronautical aluminum alloy subjected to thermal cycling were investigated in simulated Low Earth Orbit space environment. The experimental results demonstrate that the microhardness of aluminum alloys changed with the increasing of thermal cycles. The results of X-ray diffraction (XRD) and transmission electron microscopy (TEM) show that the property changes of the 2024 aluminum alloys during the thermal cycling period are closely related to the microstructural evolution. The relationship between the microstructural evolution and the thermal fatigue was also discussed.

Abstract: With high energy density, long cycle life and high voltage Lithium-ion batteries are one of very promising pollution-free power supply. The electrolytes for these batteries consist of flammable organic solvents which are serious hazard under abusive conditions especially for large-scale lithium batteries. To reduce flammability of electrolyte of lithium-ion batteries and resolve safety problem, Tris (2, 2, 2-trifluoroethyl) phosphate (TFP) was synthesized and added into electrolytes as additive. It was found that the SET decreased significantly with the increase of the concentration of TFP. When the concentration is over 20% (vol.) electrolytes are nonflammable. At the same time, with the concentration increasing, the ion-conductivity decreased and the discharge capacity also came down slowly. The electrochemistry stability of LiCoO2 cathode was improved. According to our study, it is possible to find a cosolvent or additive that makes nonflammable lithium-ion electrolyte be put into practice.

Abstract: The use of palm shells as a precursor for the production of activated carbon with physical activation was investigated. The carbonized material was impregnated with potassium carbonate and potassium phosphate to improve the yield and adsorption capability of activated carbon. The produced activated carbons were characterized by Iodine number text, Methylene blue adsorption text, Nitrogen adsorption isotherms, Scanning electron microscope in order to understand the palm shell activated carbon. The results showed that palm shell is an appropriate precursor for activated carbon. The optimum activation condition is: temperature 850°C, activating time 60 min, and steam flow rate 1.0g min^-1. Potassium carbonate-impregnated and potassium phosphate-impregnated sample showed higher value of surface area which attained 982m²/g and 973m²/g, respectively.