Advanced Materials Research Vol. 937

Abstract: The reaction mechanism of electrochemical extraction of Fe_xTi alloys direct from natural ilmenite in molten CaCl₂ has been investigated. The electrochemical deoxidation experiment process was carried out at 1000 °C and 3.8 V, and a solid oxide oxygen-ion-conducting membrane (SOM) filled with carbon-saturated liquid metal was served as the inert anode of the electrolytic cell. The macro-/micro-structure variations of the samples during electrolysis were investigated. The reaction routes from natural ilmenite to Fe_xTi alloys are proposed and discussed. It is found that element Fe is reduced firstly from ilmenite and thus serves as electronic conductor to accelerate subsequent deoxidation, Fe_xTi alloys can be produced directly from natural ilmenite by electrolysis in molten salt. It is suggested that Fe_xTi phase can be formed directly from Fe_xTiO_y compounds and/or from deoxidation-generated Ti and Fe through various reaction routes.

Abstract: The coarsening behavior of Cu₆Sn₅ grains formed at the Sn37Pb/Polycrystalline Cu interface is investigated in terms of their orientation evolution during solid-state aging. The results show that the coarsening behavior of the interfacial Cu₆Sn₅ grains during solid-state aging are quite different from that during liquid-state soldering. The occurrence of the coarsening in the solid-sate reaction is caused by the different surface energies between two adjacent grains. In addition, the texture morphologies of the interfacial grains affect their coarsening rates. In particular, the interfacial Cu₆Sn₅ grains formed at 200 oC exhibit a texture with the [0001] direction normal to the interface after 16 days of aging at 150 oC, and the formation of this texture accelerates the coarsening process of the interfacial Cu₆Sn₅ grains.

Abstract: Sewage sludge was tested as component for producing glass-ceramics with the addition of analytic reagent CaO to solve the sewage sludge disposal problems. The effect of alkalinity (Ak=mCaO/mSiO₂) on the characteristics of the glass-ceramics was investigated. Differential scanning calorimetry (DSC) and X-ray diffraction (XRD) were used to investigate thermal behavior and crystalline phase of the samples. It was found that the degree and characteristics of crystals in vitrified sludge significantly correlate to the alkalinity of the raw materials. The glass-ceramics with Ak = 0.36 possessed the best physical and chemical properties.

Abstract: Avoiding the urea deposition in the exhaust stream is one of the basic requirements for SCR system normal application. Unreasonable structure design, machining and installation position all could lead to urea crystallization on the wall of exhaust pipe and the front end surface of the catalyst, in addition, unreasonable control strategy also could deteriorate this phenomenon. The components of the urea depositions are the urea and cyanuric acid analyzed by thermogravimetry - FTIR technology. The integrated injector mounting is designed to alleviate the urea crystallization based on analysis results. The engine test and the vehicle road test are all shown that the optimal structural design and calibration strategies could avoid crystallization and sedimentation effectively in the exhaust system.

Abstract: Hydroxyl-terminated hyperbranched polyesters (HBPET) with aromatic-aliphatic structure were synthesized by melt polycondensation of isophthalic acid and pentaerythritol via A₂+ B₄ approach, at three different monomer mole ratios (A₂/B₄ =1:1, 1.5:1, 2:1, respectively). Fourier transform infrared (FTIR) spectroscopy indicated that the expected HBPET. The degree of branching of the HBPET was estimated to be between 0.39–0.45 by ¹H-NMR and ¹³C-NMR measurement. The thermogravimetric analysis ( TGA ) measurement revealed that HBPET had a 10 % weight-loss at 350°C in N₂.

Abstract: Polyamide 5,6 (PA56) fibers were successfully prepared by melt-spinning technique. PA56 fibers were subjected to hot drawing process at different draw ratio and temperature. The effect of the drawing conditions on their mechanical properties such as tenacity, tensile modulus and breaking elongation were investigated by means of tensile test measurements. The results revealed that the tenacity and tensile modulus were found to be increased, while the elongation at break decreased with the draw ratio. The improvements of the mechanical properties could be attributed to the enhanced of the molecular orientation along the fiber axis and an increase in crystallinity. On the other hand, the PA56 fibers mechanical properties do not show significant difference with the drawing temperatures.

Abstract: 2,6-DCP was found to be an efficient metabolic uncoupler to reduce sludge production. 20mg/L 2,6-DCP could reduce sludge production about 34.62%, however, it also affected nitrification seriously, the nitrification inhibition was about 76.17% compared to control. Environmental factors, temperature and pH, were varied to repair nitrification. The nitrification inhibition was decreased to 45.7% at 28±1 ^◦C and pH=8.5±0.2. Nitrification inhabitation was further decreased to 30% when the 2,6-DCP concentration reduced to 10 mg/L, the sludge reduction also decreased to17.9%. The 30-day operation data indicated that 10mg/L 2,6-DCP can also effectively reduced the sludge production about 17.9% with the COD removal efficiency decreased about 6.99% and nitrification inhabitation was about 30.91%. It shouldn’t only consider the sludge reduction when selecting the concentration of metabolic uncoupler. The application of metabolic uncoupler for sludge reduction should be cautious and need further study.

Abstract: Density (ρ), refractive index (n), conductivity (κ) and viscosity (ɳ) measurements have been carried out for binary mixtures of imidazolium based ionic liquids with ethanol at 298.15 K. Excess molar volumes have been calculated from experimental data and was fitted by Redlich-Kister equation. The density and refractive index increase with increasing ionic liquid (IL) concentration. Addition of IL leads to increased conductivity initially within these mixtures, which is subsequently followed by gradual decrease in IL-rich region showing the restricted ion mobility and enhanced interactions within these mixtures. Viscosity was found to be increase gradually with increasing IL concentration. It has been observed that solubility parameters, dielectric constant and nature of anions of ILs being used play a vital role in determining the fate of resultant properties.

Abstract: Influenced by surrounding environment, performance load and eroded by all kinds of media, the structure of lock gate prone to corrosion phenomena. Therefore, aimed at the situation of gate corrosion, to carry out the appraisal method for gate, a gate corrosion detection rating method is established. Based on the environment characteristics, taking corrosion appearance, coating thickness, the residue corrosion depth and corrosion pit depth as the index to evaluate,provides the judgment and evaluation basis for the lock gate is in need of repair.

Abstract: The corrosion inhibition of S-benzyl o-phenylenedioxydithiophosphate (BPOTP), for carbon steel in hydrochloric acid solution was studied by electrochemical measurements and weight loss measurements. Polarization curves indicate BPOTP is a mixed-type inhibitor, and the effects of temperature, hydrochloric acid concentration and immersion time were also studied. The studies of weight loss measurement show that the inhibition efficiency was up to 92.82 % at the BPOTP concentration of 40 mg·L^-1 in 1.0 M hydrochloric acid solution at 30°C. The adsorption of BPOTP on carbon steel surface obeys the Langmuir isotherm.