Advanced Materials Research Vols. 233-235

Abstract: In this paper, octadecylamine (ODA), dimethyl oxime and bromogeramine are selected to complex as a filming amine (FA). Static metal hanging slice test at low temperature is used to study the inhibition performances of the FA. And the influence of the ratio for each component in FA to the properties of the film is studied. Drip method using CuSO₄ solution, water droplets test method are employed to evaluate the quality of the film. Electrochemical methods are used to research the form mechanism of protective film. The results show that when each concentrations of ODA, dimethyl oxime and bromogeramine is 50 mg/L, 300 mg/L and 50 mg/L, the effect of the corrosion inhibit is the best, the time of the color change of the film in CuSO₄ solution is longer than 10s, water droplets could not be spread on the film, and anti-corrosion mechanism of FA is that a hydrophobic organic molecules layer on metal surface is generated to achieve the purpose of anti-corrosion.

Abstract: Silicalite-1 (pure silica MFI) membranes were hydrothermally synthesized on pretreated surface of two common stainless steel materials, i.e., AISI 304 and 316L. XRD and SEM techniques were used to characterize the membranes. Various membrane morphologies can be obtained by adjusting synthesis conditions such as the H₂O/SiO₂ ratio in the start colloid, the crystallization time and temperature as well as the substrate materials. The silicalite-1 membranes on the stainless steel surface show potential applications for regenerative fuel cooling technology in high speed flight field.

Abstract: A kind of solid acid (sulfated zirconia) was proposed to be used as the catalyst for the hydrolysis of ethyl lactate because esterification-hydrolysis was usually applied to produce lactic acid of high purity. The sulfated zirconia was prepared via a simple chemical precipitation and impregnation approach. The prepared catalysts were characterized by means of XRD, TG-DSC, FT-IR, and NH₃-TPD. Catalytic activity of the prepared catalysts was evaluated by the hydrolysis reaction of ethyl lactate. The characterization results showed that the prepared sulfated zirconia was of tetragonal phase at the optimum calcination temperature of 650°C and had strong acidity. The conversion of hydrolysis of ethyl lactate using the prepared catalyst was 82.62%. Although the conversion was lower than that of liquid acid (p-toluenesulfonicacid), the solid acid catalyst was easier to be separated from the products. It resolved the problems of pollution and catalyst reuse. This work might provide a new green process for producing lactic acid of high purity.

Abstract: Effect of CuCl source and content on formation of triethoxysilane in the direct process is described and discussed. The two sources of CuCl and the contact masses from the reduction reaction by silicon and CuCl have been investigated by X-ray diffraction, scanning electron microscope and N₂ adsorption-desorption with a purpose of studying the reasons that different CuCl sources cause different reaction effect. We found Si-Cu intermetallics in proportion to the contact area between CuCl and Si. So CuCl with the characteristics of finer particles and high specific surface area is beneficial to form vast scale active Si-Cu intermetallics. The CuCl concentration on the performance of the catalytic reaction between silicon and ethanol was investigated by online gas chromatogram. The catalyst concentration greatly influences various aspects of the direct synthesis of triethoxysilane, including the induction time, the reaction rate, the selectivity and the silicon conversion. The reaction activity and yield of triethoxysilane increase as the catalyst concentration increases. However, the reaction selectivity decreases when the catalyst concentration is more than 5%, in this case the yield of triethoxysilane is slightly lower than 10% catalyst concentration.

Abstract: A kind of cobalt complex with asymmetric tridentate ligand was synthesized and used in ethylene oligomerization. The reaction temperature and Al/Co ratio had a great influence on the activities and distributions of the oligomer with methylaluminoxane as cocatalyst, and the main products were 1-butylene and hexene. A fast deactivation process was observed from the curve of the oligomerization kinetics.

Abstract: Activated carbon-supported platinum was prepared and characterized by fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS), respectively. And the hydrosilylation of allyl glycidyl ether with trimethoxysilane catalyzed by platinum on activated carbon was discussed. The effects of reaction temperature, reaction time, feeding fashion and mixture ratio of precursors on the Pt/C catalytic this hydrosilylation were also investigated. The results showed that the reaction can generate the product of 3-glycidoxypropyltrimethoxysilane at an efficiency of as high as 97.4% under the optimal conditions.

Abstract: Carbonate hydroxylapatite (CHAP) with different carbon content synthesized by precipitation, As raw material to calcium nitrate、potassium phosphate、potassium carbonate, by changing the incorporation of potassium carbonate.The CHAP was characterized by XRD、TEM and FTIR. And through analysis compared structure and morphology of carbon hydroxyapatite with different carbon content.

Abstract: CuO-ZnO-ZrO₂-TiO₂ catalyst was prepared by parallel-slurry-mixing-precipitation method combined with addition of surfactant. The catalyst characterizations were investigated by Nitrogen adsorption-desorption, XRD, SEM and EDS. Results show that the average pore diameter of the mesoporous CuO-ZnO-ZrO₂-TiO₂ catalyst is 3.754 nm, and dispersion of CuO is better on CuO-ZnO-ZrO₂-TiO₂ catalyst. Under the conditions of reaction temperature of 503 K, reaction pressure of 2.0 MPa, space velocity of 2100 h^-1 with a H₂/CO₂ molar ratio of 3:1, the catalyst exhibited favorable activity for methanol synthesis from CO₂ hydrogenation. The selectivity to methanol and the yield of methanol were 27.42% and 4.50%, respectively.

Abstract: The use of organic solvents as reaction media for enzymatic reactions provides numerous industrially attractive advantages compared to traditional aqueous reaction systems. Hemoglobin (Hb) intercalated magadiite nano-composites was successfully prepared by exfoliation-reassembly method at room temperature and pH=7, and was used to catalyze the oxidation of o-phenylenediamine in organic solvents. Catalytic activity of immobilized Hb in organic solvents with different hydrophobicity and different functional groups were investigated detailedly. The results showed that functional groups and molecular constitution of the organic solvents were both important factors to determine catalytic activity of immobilized Hb in organic media except hydrophobicity of organic solvents.

Abstract: The adsorption of Cr⁶⁺ from aqueous solution by carbonate hydroxylapatite (CHAP) with different carbon content synthesized by precipitation. The CHAP was characterized and analyzed by TEM、FTIR and XRD. And adsorption was effected by the pH value、CHAP usage、adsorption time and other factors. The results show that under certain conditons, adsorption capacity enhanced with the carbon content increasing.