Advanced Materials Research Vols. 960-961

Abstract: Single electron transfer living radical emulsion polymerization (SET-LRP) of allyl methacrylate (AMA) coupled with 2,2,3,4,4,4-hexafluorobutyl methacrylate (HFBA) was investigated in the presence of Cu(0)/N,N,N’,N’’,N’’-pentamethyldiethylenetriamine (PMDETA) as catalyst and ethyl 2-bromoisobutyrate (EBiB) as initiator. Solid content of the emulsion and the amount of the catalyst, initiator and emulsifier were discussed for the optimal reaction conditions. Then, the emulsion was combined with thiol capped polyurethane (SHPU) under UV to form the UV curable fluorinated films. Mechanical properties and contact angle of the UV cured films were studied.

Abstract: Ceramic coatings were prepared on ZM5 magnetism substrate by micro-arc oxidation method with and without magnetism filed in silicate electrolyte. The morphology of the MAO coatings was investigated by scanning electron microscope (SEM). The friction coefficient of the MAO coatings prepared with magnetism is about 0.2 and more stable than the coatings prepared without magnetism. The polarization test indicated that the coating prepared with magnetism has better corrosion resistance.

Abstract: Organosilicon-modified epoxy esters resin was successfully prepared by solution polymerization and the effect of content of silica sol and silane coupling agent (KH560) on the resistance to water, acid, alkali and film dry, the polymerization mechanism, structure were studied, respectively. The results showed that: compared with the properties of resistance to water, acid, alkali and film dry of pure epoxy esters resin, to some extent, those of organosilicon-modified epoxy esters resin had been improved a lot. The properties of resistance to water, acid, alkali and aging increased at first and then changed little with the increase of the content of organosilicon. Especially, the comprehensive performance of composite resin was relatively excellent when the content of silica sol and KH560 was 10%, respectively. Keywords: Organosilicon; epoxy esters resin; silane coupling agent; solution polymerization

Abstract: Bipolar plate with multiple functions is one of the essential components of the PEMFC (Proton Exchange Membrane Fuel Cells) stacks. Recently, metallic bipolar plates, particularly different grades of stainless steels, have been increasingly considered due to relatively low cost, good corrosion resistance, sufficient stiffness and excellent flexibility in thin forms, and easy manufacturability [1-3]. However, the major concerns with the use of stainless steel alloys as bipolar plates are their corrosion resistance and interfacial electrical resistance under long operation conditions. Development of advanced ternary nitride coatings such as chromium silicon nitride (CrSiN) has attracted significant industrial interest in recent years [4-11]. Si addition of CrN to form CrSiN films were prepared by cathode arc ion deposition technique and magnetron sputter technique, in order to improve the characterizations of the coatings from structure to corrosion behaviors. It is reported that with the additional element of Si, the hardness and corrosion resistance of the CrSiN coatings can be greatly improved compared to that of the CrN coating. A direct link between the microstructure and mechanical properties of CrSiN coatings with varying Si contents was established [8]. With increasing Si content, the structure of CrSiN coating exhibited the transformation from a columnar-grained structure to a nanocomposite structure, consisting of CrN nanocrystallites embedded in an amorphous matrix. A maximum hardness of 26.6 GPa was found for CrSiN coating with Si content of about 6.7 at.%, while that of pure CrN was 19.4 GPa [6]. Up to now, the CrSiN is yet thoroughly investigated.

Abstract: In this work, ordered mesoporous ZnO thin films was synthesized and gas sensor properties were introduced. Mesoporous ZnO thin films were successfully formed by sol-gel process. In ZnO structure, complex agent (MEA) was used for the hydration and condensation reaction. According to the change of MEA concentration, porosity and pore arrangement, specific surface area could be changed. As complex agent concentration decreased, pore ordering was increased and gas sensitivity has the high value (8.01).

Abstract: Glass forming ability and crystallization kinetics of Al-Mg-Ni-La alloys have been investigated by X-ray diffraction (XRD) and differential scanning calorimetry (DSC). The maximum thickness achievable in glasses of Al₇₆Mg₁₁Ni₈La₅ and Al₆₉Mg₁₈Ni₈La₅ ribbons were 200 and 120 μm, respectively. The crystallization temperature and peak temperature indicated by DSC measurements displayed dependence on the heating rate during continuous heating, and were coincident with Lanoka’s relationship. The activation energies for the crystallization reaction E_x were obtained from the Kissinger’s equation. The results show the Mg addition is beneficial to the thermal stability of the amorphous phase.

Abstract: The motion characteristics of microbubble in the water or solution have important influence to crystallization process. In the paper, the movement equation of single bubble was modeled based on force equilibrium, the mechanics factors influence on the single bubble motion were discussed, and the velocity of microbubble was analysed with the different bubble sizes. The results show that the velocity of microbubble in static water is increasing with time increasing, the influence of virtual mass force and Basset force caused by the acceleration on the velocity of microbubble must be considered in the initial stage of microbubble motion. In the processes of microbubble motion, compared with constant microbubble radius the variation laws of velocity fluctuations mean with microbubble radius changing are uniform.

Abstract: Several conformance control agents, including preformed particle gel, emulsion microspheres, continuous chromium gel and underground starch graft copolymer gel were evaluated. The properties such as gelation time and gel strength of gel, and expansion of particles and microspheres were tested at high temperature. Also, the injection pressure, plugging strength and resistance factor were measured using the artificial low permeability cores with fractures. It was shown that, for particle type conformance control agents, the particle size should be adaptable with the fracture width. Also, for continuous chromium gel, the added polymer concentration higher, the viscosity is higher, with higher plugging strength. The plugging and strength should be coordinated. The starch graft copolymer gel is easy to be injected into formation and has good plugging property. The results show that underground starch graft gel is more suitable for conformance control in low permeability formation with fractures.

Abstract: The V₂O₅-WO₃/TiO₂ honeycomb catalysts with cordierite modified were prepared by solid-liquid mixing method. Its thermal stability, crystal structure, abrasion resistance and activity were studied by XRD, abrasion equipment and simulated flue gas analyzer,respectively. The results indicated that V₂O₅-WO₃/Cordierite-TiO₂ honeycomb catalyst possessed a better thermal stability, mechanical property and activity at the higher temperature comparing to commercial catalyst. There was no rutile phase present after the catalysts were calcined at 700°C, and the vanadia and tungsten trioxide phases could be apparently visible on TiO₂. Key word:V₂O₅-WO₃/ TiO₂; Cordierite; flue gas denitrification; NO_x; selective catalytic reduction (SCR)

Abstract: Si Wafer, pre-weathered TiZn alloy (TiZn-P), Aluminum (Al), and hot-dipped galvalume steel (G.L.) are chosen in this work for the study of hydrophobic coating to various substrates. Various amounts of TS-720 hydrophobic nanoparticles were mixed into ITRI hydrophobic agent (H.A.), and this mixture liquid was applied onto different material surfaces by using a coating bar technique. High contact angle near 140^o are achieved in all samples with 2.5 wt% TS-720 in ITRI H.A. mixture.