Advanced Materials Research Vols. 239-242

Abstract: The composites with high permittivity and low dielectric loss were obtained. The fillers were the core@shell structure of the self-passivated aluminum (Al) particles (denoted as Al@Al₂O₃). The Al₂O₃ interface between Al and polymer matrix played important role in tailored dielectric properties of composite. The transmission electron microscopy (TEM) indicated that the Al₂O₃ shell was 2.7 nm. The self-passivated Al/polystrene (PS) composite displayed that the permittivity almost independed on frequency in wide range (10²-107 Hz) and retained high-steady level, which is 27.4 times higher than that of a neat PS. On the other hand, the effect of size ratio value of core/shell in core@shell structure filler on dielectric performance of self-passivated Al/PS composites was also explained. The insulating oxide layer (Al₂O₃) restricts the electron transfer between Al particles. Moreover, the self-passivated Al/PS composites exhibited very steady dielectric performance at the wide temperature range (－60 ~60 °C). The composites have potential application in dielectric materials.

Abstract: In this investigation, antibacterial property of active packaging of microencapsulated cinnamon oil combined with ZnO-coated PVC film was investigated. Microencapsulated cinnamon oil was prepared by simple coacervation and the morphology of microencapsulation was also analyzed by SEM. Result also showed that microencapsulated cinnamon oil and ZnO-coated PVC film exhibited good antibacterial activities against E. coli and S. aureus. In vivo fruit test, the active packaging of microencapsulated cinnamon oil combined with ZnO-coated PVC film showed good inhibition property the growth of bacteria on the surface of fresh-cut apple slices.

Abstract: Cutting processes of single abrasive grain were simulated respectively by fluid-solid interaction method and Smoothed Particle Hydrodynamics method. Advantages and disadvantages of the two methods were compared. Smoothed Particle Hydrodynamics method is superior to fluid-solid interaction method in simulating the deformation behavior of workpiece material for the motion of SPH particles. According to the simulation results, it is concluded that workpiece material occurs plastic deformation, flows to the side and front owing to the extrusion of abrasive grain, and finally forms chip in front of abrasive grain.

Abstract: Thermal barrier coating (TBC), which consisted of a NiCoCrAlY bond coat (BC) and a ZrO₂-8 wt.%Y₂O₃ topcoat (TC), was fabricated on the nickel-base superalloy by air plasma spray (APS). The BC and TBC was treated by vacuum heat treatment (VHT). The oxidation of coating with and without VHT has been performed at 1050°C. Oxidation behavior of coatings and thermally grown oxide(TGO) scale were studied by SEM with EDS. As shown in the results, after treating by VHT, a continuous Al₂O₃ layer formed more rapidly on the VHT coating than that formed on the APS coating, which can act as a diffusion barrier to suppress the formation of other detrimental oxides. The pre-oxidation treatments reduced the growth rate and extend the steady-state growth stage. The TGO in VHT TBC was still a single layer Al₂O₃ oxide after 120h. However, after same oxidation time, the TGO in APS TBC produced a dual-layer oxide consisting of an inner Al₂O₃ layer and outer spinel layer. Therefore the VHT improves the oxidation resistance of APS coating.

Abstract: The CO₂/H₂S corrosion behaviors of oil tube steels N80 and P110 at different H₂S partial pressure (0.2psi, 3psi, 9psi, 18psi) were investigated by autoclave corrosion tests, corrosion rate calculation and corrosion morphology observation. The results show that with the increase of H₂S partial pressure the CO₂/H₂S corrosion rates of both steels increase at first and then decrease after the peaks appear at 3psi H₂S.

Abstract: The Ti-Al composite electrode materials was prepared by hot press diffusion bonding in this article, and by the scanning electron microscopy (SEM), the energy dispersive spectroscopy (EDS), four-probe method, electrochemical workstation test means were used to test the structure and properties of the samples. The results show that the method of hot pressing diffusion sintering can achieve metallurgical bonding of Ti and Al with static pressure of 6MPa, holding times of 120min, in Ar and bonding temperature higher than 550°C,as well resistivity of the composite had dropped significantly, it was only 1/10 of pure Ti. The electrochemical properties of the composite electrode materials is also much better than pure Ti anode, and preparation conditions on electrochemical properties and the resistivity is consistent with law. This also shows that the conductivity of metal matrix will directly affect the catalytic properties of electrode materials for electrochemical. Therefore, changes in the composition of the electrode base material and structure not only reduces the cost and improve the performance of the electrode, also reached the purpose of energy saving.

Abstract: The influence of amino acids on the corrosion behaviour of steel in H₂SO₄ solutions was studied by potentiodynamic polarization, AC impedance and weight-loss. The Potentiodynamic polarization curve results show that compound amino acids are mixed-type inhibitors which inhibit the reactions of anode and cathode; AC impedance results show that the ternary complex inhibitors have a good synergistic effect and high corrosion rate which can be proved by Resistance (Rt), double-layer capacitance (Cdl), Resistance modulus(︱Z︱), and phase angle from the Nyquist chart, Bode chart and phase angle chart. The weight-loss method show that the corrosion efficiency of composite amino acids are over 90% in 0-16 hours, 30-50°Cand 0.4-2.0mol / L sulfuric acid.

Abstract: The impacts of multi-monomers melt grafting blends of maleic anhydride(MAH) and Styrene (St) on the crystallization behavior, morphology and mechanical properties of PA1010/ABS/PP blends were studied through the methods of SEM,themal analysis, mechanical properties analysis. The results showed that the graft copolymer generated in situ by the anhydride groups of g-PP and the amino end of PA1010 reduced the interfacial tension of blends efficiently, and the interaction of the styrene groups of the graft copolymer and ABS is helpful to improve the compatibility of three components during the melt blending process. The size of dispersed phase in blends is reduced obviously and the mechanical properties have a great improvement when the percentage of g-PP in the PA1010/ABS/PP blends increases to 10%. The tensile strength of the compatibilized PA1010/ABS/PP blends is improved by 11.7%,and the impact strength and elongation at break are increased 4 times and 4.9 times, respectively.

Abstract: 3D nanoporous coordination framework [Ni₂(nic)₄(H₂O)]_n (nic=Nicotinic acid) was obtained hydrothermally from a mixture of NiCl₂^.6H₂O and 3-cyanopyridine. X-ray single crystal analysis revealed that it consists of “mushroom-shaped” channels along a axis suitable for gas storage. N₂-adsorption studies at 77 K revealed a Langmuir surface area of 200 m²/g and a pore volume of 0.12 cm³/g. The compound shows dynamic dehydration and rehydration behaviors with the formation of 0D coordination [Ni(nic)₂(H₂O)₄], accompanied by crystal-to-crystal transformation. The structural transformation significantly changes the character of magnetic exchange interactions and gas storage.

Abstract: High stress makes backfill body present the rheological properties in deep mine. This paper first uses RRTS-ⅢA to carry on creep test of specimen in different proportion, according to ε-t curves under different load levels to determine the specimen’s long-term strength, based on the exponential relationship of rock block and rock body, the long-term compressive strength is derived, combining with concrete parameters of working face, mixture ratios of filling material which meet long-term stability are selected, while analyzing the support resistance of backfill body. The results show that this design can effectively avoid the rheological instability of backfill body.