Advanced Materials Research Vols. 631-632

Abstract: The influence of different additives (poly-γ-glutamic acid, polyethylene glycol) on the thermostabitity of zearalenone-degraded enzyme at 70°C has been studied in aqueous medium. The results obtained show a stabilizing effect in the presence of poly-γ-glutamic acid (ethylene glycol, glycerol, erythritol, xylitol, and sorbitol) and for most of the γ-PGA-PEG used. The influence of the monovalent ions on zearalenone-degraded enzyme thermostability can be correlated to the lyotropic series of Hofmeister.

Abstract: The rheological behavior of polyamide-66 (PA66)/liquid crystal polymer (LCP) blends and the effect of liquid crystal polymer on melt flow rate were studied. A torque rheometer was used to investigate the rheological behavior of the PA66/LCP blends, and the effects of mass fraction of LCP, compatibilizer (PS-g-MAH), blending temperature and rotor speed on the rheological behavior of the blends were analyzed by an orthogonal experiment method. The results showed the above factors’ effects on the equilibrium torque of the blends were different individually, and the rheological behavior of the blend strongly depended on the LCP content. The melt flow rate was enhanced by a small content of LCP, and decreased with increasing LCP content.

Abstract: The pyrolysis of phenolic-formaldehyde (PF) resin was studied by TG-MS technique. The structure changes of pyrolysis of PF resin heated to different temperatures were investigated by Fourier-transform infrared rays (FTIR). The experimental results shows that the pyrolysis of PF can be divided into three stages. Ether bonds and unreacted terminal hydroxymethyl groups of the cured resin degradate in the first stage. In the second stage, crosslinks are broken, involving formation of a thermally crosslinked intermediate structure and the breaking of methylene bridges into methyl groups. Cyclodehydration and forming char of phenolic hydroxyl occurs in the third stage. The thermal stability and char yield of resin are depended on the pyrolysis of methylene bridges.

Abstract: As an important component in 193nm laser system, high-reflectance (HR) coatings with excellent optical and mechanical properties are needed urgently. In this study, we designed and produced three different HR coatings at 193nm, Al₂O₃/ AlF₃ coating, LaF₃/ AlF₃ coating and a double stack mirror with combination of Al₂O₃/ AlF₃ and LaF₃/ AlF₃. With 14 layer pairs, the reflectance of Al₂O₃/ AlF₃ coating could reach 98% which could not get higher duo to the absorption of Al₂O₃. The reflectance of LaF₃/ AlF₃ coatings could achieve 98.13% with 15 layer pairs. When the layer pair increased to 16, the reflectance lessened ascribed to steep rise in scattering loss caused by micro-cracks occurred in the coatings. A mirror with combination of Al₂O₃/ AlF₃ and LaF₃/ AlF₃ could obtain the reflectance of 98.78% as deposited. Even 4 months later the value could still reach 98.47% which was an excellent candidate for practical application.

Abstract: Using polyethylene oxide (PEO) as template, the new types of mesoporous phosphate compound which belongs to NaZr₂(PO₄)₃(NZP) family were synthesized by copreciptate, sol-gel and mechanochemical activation(MA) route respectively. The physical phase and pore structure of the synthesized powder materials were characterized by X-ray diffraction (XRD) and N₂ adsorption–desorption. The results showed that the crystalline NZP family compound with mesoporous structure is formed by sol-gel route followed with calcination as well as MA method followed with hydrothermal treatment when the mole ratio of PEO to Zr is 1:10, and the specific surface area, average pore diameter and pore volume of the synthesized powder is 20-50m²/g, 3-6.nm and 0.05-0.12cm³/g respectively. The above research results indicate that it is promising to expand the application field of the powder of NZP family from low thermal expansion ceramics to catalytic materials.

Abstract: In order to reveal the influence of oxidization on the properties of AlF₃ films, single layers of AlF₃ were deposited at different substrate temperature by thermo evaporation technique with or without oxygen injected into the coating chamber. The chemical composition, total stress, optical properties and laser damage resistance of samples were characterized. Comparative study indicates the AlF₃ films prepared under higher oxygen pressure have more oxides which result from hydration process in atmosphere. The presence of oxides also reduces total stress and optical absorption of the fluoride coatings.

Abstract: TiO₂-N-methyldiethanolamine(MDEA)-H₂O nanofluids were prepared by dispersing TiO₂ nanoparticles in the 50wt% (mass fraction) MDEA solution. The stability of nanofluids was studied by the method of absorbance. Only with mechanical agitation, the nanofluids can keep stable at least 48 h without any dispersant. The surface tensions; kinematic viscosities and thermal conductivities of the MDEA solution were measured at the temperature of 20 °C when the TiO₂ na-noparticles concentration was 0.05wt%, 0.2wt%, 0.4wt% and 0.8wt%. The results show that they all increase with increasing concentration of the nanoparticles. The maximum enhancement of the surface tension, kinematic viscosity and thermal conductivity is 0.6 %, 4.6 % and 5.9 % respectively at the concentration of 0.8 wt%. The influence of nanoparticles on CO2 bubble absorption in the MDEA solution was studied. It can be found that the CO₂ absorption rate can be enhanced by 1.95%, 6.53%, 7.79%, 11.54% when the TiO₂ nanoparticles concentration is 0.05wt%, 0.2wt%, 0.4wt% and 0.8wt% respectively. The possible mechanisms for the phenomena in experiments and related results are also explained.

Abstract: A novel environmental friendly catalyst, H₄SiW₆Mo₆O₄₀/SiO₂was synthesized by a sol-gel technique, and characterized by FT-IR and XRD. Catalytic application of the catalyst for synthesis of n-butyl methacrylate was investigated. The variation of different reaction parameters were studied by orthogonal design. Under optimized conditions, that is, molar ratio of methacrylic acid to n-butanol is 1:1.7, catalyst dosage is 0.75 %, volume of cyclohexane is 12 mL and the reaction time is 2.5 h, the yield of n-butyl methacrylate reaches 85.3%. The results reveal that the H₄SiW₆Mo₆O₄₀/SiO₂O2 catalysis is an execellent catalyst for synthesis of n-butyl methacrylate. Introduction

Abstract: In this paper, the produced water in Daqing oilfield was detected, includes the viscosity and concentration ratio of living polymer (LH-1), interfacial tension and swelling rate of particle polymer (LHP-1). And its adaptability in low permeable fracture core was also tested. The results show that the injection property is good if the living polymer (LH-1) and the particle polymer (LHP-1) are used together, the volume-expansion particle polymer can effectively plugging the high permeable layer in bottom of the reservoir and improve water injection profile. The best injection volume of LH-1is 0.32 PV, and enhances oil recovery rate is 18.4%.

Abstract: Temperature-sensitive calcium alginate-based microspheres were prepared in two steps. Firstly, free-radical polymerization of temperature-sensitive N-vinylcaprolactam monomer was performed in aqueous solution of sodium alginate, yielding a mixed aqueous solution bearing temperature-sensitivity composed of poly(N-vinylcaprolactam), sodium alginate-graft- poly(N-vinylcaprolactam) and sodium alginate. Then temperature-sensitive composite microspheres were prepared by inverse emulsification-crosslinking using the as-prepared solution as water phase, n-hexane as oil phase, Span-85 and Tween-85 as emulsifiers and calcium chloride as crosslinker respectively. The morphology and temperature-sensitivity of the composite microspheres were investigated by scanning electron microscope and turbidity method respectively. The controlled release behavior of the microspheres towards temperature was investigated preliminarily using berberine as a model drug.