Advanced Materials Research Vol. 549

Abstract: Spherical V-MCM-41s with different diameter are synthesized by direct hydrothermal method through the precise control over the molar ratio of NaOH/TEOS. Vanadium supported on spherical MCM-41s is also prepared by impregnation methods. They are used as heterogeneous catalysts for the oxidation of styrene with H₂O₂ as oxidant. The results suggest that all catalysts have high catalytic activity, which increases with their diameter decreasing.

Abstract: SrFe_xCo_0.5O_3-δ (x=0.5, 0.75, 1.0, 1.25) powders have been synthesized by the solid state reaction process. The effect of Fe content on the microstructure and properties of the SrFe_xCo_0.5O_3-δ powders were investigated in detail by X-ray diffraction (XRD), scanning electron microscopy (SEM) and thermo-gravimetric analysis and differential scanning calorimeters (TGA/DSC). XRD results reveal that the phases of the SrFe_xCo_0.5O_δ powders are dependent on the content of Fe. X-ray diffraction. SEM images show that the obtained powders have similar morphology with particle structure and uniform size distribution. The phase transition from ordered brownmillerite structure to disorder perovskite structure is strongly dependent on the content of Fe by the TGA/DSC analysis of the SrFe_xCo_0.5O_3-δ powders. Phase transition temperature increases from 770°C to 800°C with the x value in the SrFe_xCo_0.5O_3-δ increasing to 1.0. But the phase of the SrFe_1.25Co_0.5O_3-δ powder maintains unchanged behaving good phase stability and chemistry stability.

Abstract: Acrylic acid (AA) and stearyl acrylate (SA) were co-polymerized with vinyl-ended polysiloxane using AIBN as the catalyst. The polymer has been characterized by FT-IR and1H-NMR techniques. The co-polymer can be used as retaining agent, which has the ability of fatliquoring and water-proofing for full chrome leather. The results were compared with non-reactive silicone treated leathers on the aspect of reactive ability with mineral-tanned leather. It was found that the synthesized co-polymer has superior permanent anti-water properties when used on full chrome leather.

Abstract: The density, viscosity, conductivity and the electrochemical window of 1-buthyl-3-methyl- imidazolium Chloride ionic liquids([Bmim]Cl) and its water mixture have been determined at 298.15 K and atmospheric pressure. It was found that the density and conductivity of [Bmim]Cl/water, increase with the increase the water concentration at the same temperature, whereas the viscosity and electrochemical windows of [Bmim]Cl/water decrease. The viscosity of pure ionic liquids decreases with the increase of the temperature, whereas the conductivity increases. The relationship between the conductivity and the temperature agrees well with the Arrhenius equation k=k_∞exp[-E_a/k_BT] and the active energy of conduction is determined accordingly.

Abstract: Octaepoxysilsesquioxane (POSS-Ep), a kind of functional polyhedral oligomeric silsesquioxane (POSS) was cured with 4,4'-diaminodiphenylsulfone diamine (DDS) in this study. Possessing epoxy groups, it can be cured thermally with certain curing agents including amines. Differential scanning calorimetry (DSC) was used to determine the curing techniques of the POSS-Ep/DDS resin system in this study. The appropriate curing technique for this resin is set as: 130°C/2h+ 160°C/2h+200°C/2h.

Abstract: The copolymerization reaction of m-toluidine and aniline has been induced by D-camphorsulfonic acid. When the total concentrations of the acid, the oxidant and the monomer were maintained, the ratio of two types of monomers was varied to realize the structure and property control of m-toluidine-aniline copolymers. FTIR, UV-Vis, CD and SEM were utilized to characterize the products. The results showed that the synthesized copolymers were of fiber and tube structure with the diameter of approximately 70 nm. The introduction of methyl moiety in the molecular chain of benzene weakened the conjugation and blue shifts were observed in both FTIR and UV-Vis spectra. Besides, CD spectra verified the chirality of the copolymers. Negative cotton effect could be discerned at 400 nm and the chirality inversed when [m-An]/[An]=1:5.

Abstract: Near-infrared (NIR) spectroscopy combined with partial least squares (PLS) regression and Savitzky-Golay (SG) smoothing was successfully applied for the rapid no-reagent determination of chemical oxygen demand (COD) in sugar refinery wastewater. Among 141 samples, 60 were randomly selected as the validation set. The remaining 81 samples were divided into the calibration set (50 samples) and the prediction set (31 samples) for a total of 20 times with certain similarities. The results showed that the short-wave NIR region (780 nm to 1100 nm) can be used as information waveband of COD in sugar refinery wastewater. The optimal SG smoothing parameters and PLS factors OD, DP, NSP, and F were 5, 5, 7, and 6, respectively. The modeling effects M-SEP_Ave, M-R_P,Ave, M-SEP_Std, and M-R_P,Std were 24.3 mg/L, 0.971, 2.7 mg/L, and 0.007, respectively. The validation effects V-SEP and V-RP were 25.9 mg/L and 0.963, respectively. The results indicated that the method has good prediction effect and stability, and provided a reliable analysis model and valuable references for designing specialized instruments.

Abstract: The phenol degradation characteristics and immobilization of an Acinetobacte strain HY1 were carried out. The effects of phenol concentration, temperature, pH and NaCl dosage on the growth of HY1 and phenol degradation rate were investigated. The results showed that When the bacteria was cultured in 0.5 g/L phenol solution at 35 °C and pH 7.5 with shaking speed 120 r/min, liquid volume in flask 50 mL and inoculation amount 20 % for 6 h, the degradation rate of phenol was over 95 %. Compared with free bacteria, immobilized bacteria had a higher phenol degradation rate after a long culture time.

Abstract: A two-component polyurethane adhesive based on solvent-free was prepared with PBA, vegetable oil polyols, IPDI and several different small molecular polyols as main raw materials. The influences of different mole ratios of NCO groups (from prepolymer )and OH groups (from the mixed polyols) on water absorbing capacity and T-style peeling strength were studied, as well as the effects of small molecular polyols on curing speed, heat resistance, water absorbing capacity and T-style peeling strength. The results showed that PU adhesive performed the best when mole ratio of NCO/OH was 1.3 in this experiment. And small molecular polyols added to the adhesives can not increase the curing speed and the ability of heat resistance. However, it could significantly improve the adhesion strength of PU adhesive, and adding appropriate amount of small molecular polyols selectively could improve its water resistance.

Abstract: Native corn starch (NS) was activated by treatment with NaOH /Urea /H₂O solution at low temperature to improve its chemical reactivity. Effects of the activation on the molecular level structure and morphology of the corn starch were investigated by mean of SEM. It was found that the average particle size of activated corn starch (AS) decreased to nanometer level, smaller than those of NS. The cold water solubility (CWS) has been increased from 0.45% to 96.4%. Effects of the activation on reactivity of the corn starches were investigated by analyzing the influences of the activation on degrees of substitutions (DS) of the esterifications. The DS of AS was higher than that of NS, from 0 to 0.1578, which indicated that NaOH/urea activation enhanced the chemical reaction activity of corn starch.