Advanced Materials Research Vol. 549

Abstract: With octyl butyl dimethyl ammonium bromide (OBDAB) as accelerant, adsorption kinetics of dyeing silk with three reactive dyes was studied in this paper. As concentration of OBDAB increased, the dye-uptake rate increased. The highest dye-uptake rates of three reactive dyes could reach to 89.40%~98.98% and the concentration of OBDAB was only 6-8g/L. This showed OBDAB was an effective accelerant. Pseudo first- and second-order kinetic models were used to analyze the adsorption kinetic data. The experimental data were found to follow the second-order kinetic model. Meanwhile, the initial dye adsorption rates of reactive red dye B-3BF, reactive yellow dye B-4RFN and reactive orange dye B-2RLN increased as temperature increased, and the activation energy of them were found respectively to be 28.42,13.14,32.90 kJ/mol.The positive values of and obtained indicated that reactive dyes adsorption with OBDAB as accelerant was an endothermic process. The conclusion showed OBDAB was a potential accelerant.

Abstract: MCM-22 “family” zeolites (MCM-22, MCM-49 and MCM-56) have been synthesized hydrothermally by dynamic method. All materials were characterized by different techniques, such as XRD, N2 adsorption-desorption and NH3-TPD. The catalyst performance of MCM-22 “family” zeolites have been studied on the alkylation of benzene with propylene in liquid phase. Result shows that MCM-22 “family” zeolites are excellent alkylation catalysts for the produce of cumene. Compared to MCM-22 and MCM-49, MCM-56 shows higher catalytic activity in a relatively low reaction temperature and higher monoalkylation selectivity in a relatively low benzene-to-propylene ratio.

Abstract: Diethylene glycol (DEG) is the by-product of the hydration of ethylene oxide. With the rapid development of China's ethylene industry and the increased production of diethylene glycol, taking full advantage of the diethylene glycol resources to develop downstream products and expanding the use of diethylene glycol is becoming more and more important. In this paper, we introduce the applications and manufacturing methods of diethylene glycol, and elaborate the advantages and disadvantages of various methods. Furthermore, we present a new approach to synthesis industrial raw material diethylene glycol by ethylene glycol as raw material and ionic liquids as catalyst.

Abstract: Nanoparticles of the bioinorganic complex of bismuth and serine can be prepared very easily by a room temperature solid-solid reaction with the raw materials of bismuth triiodide and serine. The complex is characterized by elemental analysis, X-ray powder diffraction and transmission electron micrograph. The characterizations indicate that the composition of the complex is Bi[I(HOCH₂CHNH₂COO)]_1.5. The crystal structure of the complex belongs to orthorhombic system with the lattice parameters: a = 0.8355 nm, b = 1.8688 nm and c = 2.2511 nm. The average diameter of the bioinorganic complex nanoparticles is about 40 nm.

Abstract: The hydrogenolysis of biomass-derived glycerol was studied on Ru-Co bimetallic catalysts, including Ru-Co/TiO₂, Ru-Co/ZrO₂, Ru-Co/SiO₂ and Ru-Co/γ-Al₂O₃. The addition of Co to the Ru-based catalysts can promote the selectivity to 1,2-propanediol (1,2-PDO). The support material and Ru/Co atomic ratio has a significant effect on the catalytic performance. Ru-Co/ZrO₂ exhibited the best performance as regard to both the activity and the selectivity to 1,2-PDO. Co is a promising second metal component to adjust the catalytic properties of Ru-based catalysts for the selective hydrogenolysis of glycerol.

Abstract: The reaction of Et₃GeCH=CH₂ + Et₃SiOH → Et₃SiO–Ge–Et₃ + CH₂=CH₂ has been studied using quantum chemistry methods. Geometries of reactants, transition states, and products have been optimized respectively at the b3lyp/6-311+g(2d,2p) level. The rate constants were evaluated using canonical variational transition state theory (CVT) and canonical variational transition state theory with small-curvaturetunneling contributions (CVT/SCT) over the temperature range of 200-3500K. The CVT/SCT rate constants exhibit typical non-Arrhenius behavior, and a three-parameter rate-temperature formula has been fitted as follows: k(T)=1.43×10^-38T ^5.41exp(-13200/T) (in units of cm³ molecule^-1s^-1).

Abstract: Chemical membrane coating method was adopted for AZ91 magnesium alloy surface to explore the preparation method for cerium (Ce) conversion membrane, lanthanum (La) conversion membrane and double rare earth conversion membrane. The methods such as Scanning Electron Microscope (SEM), Energy Spectrometer (EDS) and X-ray Crystallography (XRD) were introduced for the detection of conversion membrane. The experiment results revealed that the corrosion resistance of double rare earth conversion membrane would get strengthened firstly, and degraded later along with the prolongation of conversion time. The corrosion resistance from low to high of conversion membrane is cerium (Ce) conversion membrane < lanthanum (La) conversion membrane < double rare earth conversion membrane. Therefore, double rare earth conversion membrane is more effective to improve the corrosion resistance for magnesium alloy and its corrosion resistance is better than that of single rare earth conversion membrane.

Abstract: Ultrafine Cr3C2 powders with globular-like particle of ~0.3-0.8 μm were synthesized by a new precursor method, namely carbothermal reduction of complex chromium oxide-carbon mixture, which was made initially from salt solution containing chromium and carbon elements by air drying and subsequent calcining at 400 °C for 1 h. Phase composition of reaction products was discussed by X-ray diffraction (XRD), and microstructure of the calcined powders and final products was studied by scanning electron microscopy (SEM). The results show that the synthesizing temperature of Cr₃C₂ powders was reduced greatly by the new precursor method. Thus, the preparation of ultrafine Cr₃C₂ powders is at only 1000 °C for 2 h. The lowering of synthesizing temperature is mainly due to the homogeneous chemical composition of the complex oxide-carbon mixture. There is a coarsening tendency of Cr₃C₂ powders with the increase of reaction temperature and time.

Abstract: A series of cyanate ester resin (CE) based organic-inorganic hybrids containing different content (0, 5, 10, 15 and 20 wt%) of epoxy functionalized polyhedral oligomeric silsesquioxane (POSS-Ep) were prepared by casting and curing. Impact and flexural strengths of the hybrids were investigated. Results showed that CE10 containing 10wt% of POSS-Ep displayed not only the optimum impact strength but the optimum flexural strength.

Abstract: The adsorption behavior of methyl orange aqueous solution was investigated on husk-based activated carbon. The effects of key factors, i.e., degassing pretreatment, adsorption time, temperature, adsorbent dosage and initial concentration, on the adsorption efficiency were measured. The kinetic adsorption curves and adsorption isotherms were fitted with theoretical model. The results show that the removal efficiency of methyl orange could be significantly improved by degassing pretreatment, prolonging the time, lowering temperature or reducing the initial concentration. In the context, adsorption equilibrium will be achieved up 90min. Furthermore, adsorption rate will be enhanced by the increase of the amount of activated carbon. In conclusion, adsorption isotherm and adsorption kinetics can be fitted well with Freundlich equation and pseudo-first Lagergren model, respectively.