Advanced Materials Research Vols. 233-235

Abstract: Thin silicon nitride films were prepared on PET by r.f. reactive sputtering. Deposition Rate, reactive mechanisms, the thickness attribution, chemical stoichiometry and impurity were studied by means of RBS, XPS, and ellipsometer. Results show that chemical stoichiometric films with N-to-Si atomic ratio of 4:3 were achieved even at room temperature. Depth profiles of XPS and SIMS reveal that oxide exists only at the interface between nitride and substrate and Ar atoms are buried in the films.

Abstract: Microwave heating was efficient and the regeneration time was shortened compared to conventional thermal heating. Experiments were conducted to demonstrate that spent zeolite can be regenerated for reuse by microwave irradiation. The spent zeolite tested was prepared from the aqueous solutions of methylene blue. The effects of microwave irradiation time, microwave power on the regeneration efficiency were presented. The results show that microwave irradiation time and microwave power played significant role on the regeneration efficiency. It was concluded that microwave irradiation may be effective method for dye-loaded zeolite reuse.

Abstract: The Au/SiO₂ nanocomposite was produced using surface active agent P123, and its optical absorption spectra was measured by spectrophotometer. It was found that the intensity of absorption peak was strengthened and underwent a red-shift as the neutralization reaction time extended. The variation of optical extinction property of one gold particle (GP) with different size had been investigated by Mie theory. It was found that the extinction property of the single spherical GP possessed an obvious size effect. The extinction property of Au/SiO₂ nanocomposite had been analyzed by Maxwell-Garnett (MG) theory. It showed that the extinction peak underwent a red-shift and the extinction intensity was strengthened when the size of gold nanoparticles (GNs) increased. The theoretical and the experimental results show that the extinction property of Au/SiO₂ nanocomposite changes because the scattering effect of GNs are strengthened when their sizes increased by controlling the neutralization reaction time.

Abstract: The curing process of tetrabromo-bisphenol-A epoxy resin (TBBPAER) with 4,4´-diaminodiphenylsulfone (DDS) was investigated by Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC) and torsional braid analysis (TBA) methods. FTIR results indicated that the maximum reaction velocity was observed at initial stages at higher temperature, but it was occurred at conversion =10 - 40 % at lower temperature. It showed that there is the crossover from the autocatalytic model to the nth-order mechanism when the temperature was increased. While the double glass transition temperatures occuring in the system, according to the microstructure of the reactant, a theoretical and reasonable explanation may arise from this article.

Abstract: Nano-structured mesoporous silica with highly ordered 2D hexagonal topology has been synthesized using novel surfactant cetyltrimethylammonium tosylate (CTATos) as template via directly hydrothermal treatment at high temperature of 175 °C and varied crystallization time. The maximum pore wall thickness is up to 2.2 nm calculated by BdB method from desorption branch. The enlargement of pore wall thickness and unit-lattice of currently synthesized MCM-41 silica is attributed to the migration and subsequent deposition of the silicate species in the inner pore channel.

Abstract: Two novel intercalation composites (Cu²⁺/GO and Zn²⁺/GO, GO: graphite oxide) were prepared by coordinate chemistry, and characterized by XRD, SEM, EDS, IR and XPS. The results indicated that the two composites all have the lamellar structure with a wider spacing distance than that of graphite oxide. The metal ions are high dispersed in the graphite oxide.

Abstract: At present, offshore drilling operations often use buttress thread casing as surface casing. The design conception of buttress thread casing comes from the offshore drilling’s demands and this kind of casing is mainly used as surface casing. This paper has taken material mechanical experiment, numerical simulation analysis and field test, the research results show that the various parameters of buttress thread casing fully complies with the drilling design requirements and the offshore oilfield production demands. This product can reduce drilling cost effectively, improve working efficiency and safety, and realize manufacture domestically. Meanwhile, the development of this project will fill the blank of the ERW (Electrical Resistance Weld) casing in CNOOC (China National Offshore Oil Corporation), and have a broad prospect of application.

Abstract: To obtain high performance TiO₂ nanotube arrays (TNAs)-based material is interesting because of its wide applications in photocatalysis field such as solar energy conversion, photocatalysis and sensors. In the present work, the well-ordered TNAs were prepared by electrochemical anodization of titanium foil in the SO₄²⁻/F⁻ based electrolyte under 20 V for 2 h during which the Ti foil and Pt wire were used as anode and cathode, respectively. The FESEM results showed that the as-obtained TNAs were well-aligned on Ti substrate with ~ 1.5 μm in length and ~ 100 nm pore in diameter. The XRD results indicated that the as-formed TNAs was in the form of amorphous and could be transformed into crystalline anatase phase under the heat treatment at 450 °C. Meanwhile, the UV-vis diffuse reflectance spectra demonstrated that the band-gap of the obtained TNAs was narrower than the commercial TiO₂ nanoparticles, indicating a better photocatalytic activity of the as-prepared TNAs over the commercial TiO₂ nanoparticles.

Abstract: In order to understand the adsorption property of wettability reversal surfactant, the adsorption rule of the wettability reversal surfactant on hydrophilic surface and lipophilic surface was studied, and the adsorption behavior of the wettability reversal surfactant on hydrophilic surface and lipophilic surface was studied by Atomic Force Microscope (AFM). The results show that there is a saturated adsorption capacity of all the wettability reversal surfactants on sandstone surface, and the adsorption quantity on lipophilic surface is bigger than that on hydrophilic surface. The AFM study show that the wettability reversal surfactant tends to distribute where is close to the oil droplet. Consequently, the wettability reversal surfactant is favorable for using in lipophilic surface.

Abstract: As for the difficulties in the water injection profile controlling in the offshore oilfields, a kind of polyacrylamide emulsion and its relative profile controlling system were developed in this study. Laboratory experiments have shown that the dissolution time of the emulsion polymer into the sea water is less than 15 minutes, and the viscosity of the polymer solution is larger than 15 mPa·s when the polymer concentration is 2000 mg/L under the temperature of 70°C. The viscosity of the polymer crosslinking system is larger than 150 mPa·s, and the modulus elasticity of the crosslinking system is larger than 500 mPa. A pilot test on two wells from the Shengli Chengao Oilfield was conducted to verify the practical application performance of the emulsion polymer. The pilot test shows that after 2 months emulsion polymer injection, the bottomhole pressure of the production wells has increased by 1.48-1.79 MPa, the oil production from one correspondent well has increased from 28.67 t/d to 35.8 t/d, and the water content in the production flow has decreased from 52.3% to 41.7%. It is believed that the developed emulsion polymer and its crosslinking system have a wide application to the development of Shengli offshore fields.