Advanced Materials Research Vols. 239-242

Abstract: A new compound, 1,1-thiene-2,5-diyldibutane-1,3-ditone, having a large conjugation structure, has been synthesized by the Claisen reaction. And the compound was characterized with IR and ¹H-NMR; its structure of enol form was confirmed by the calculation of ChemBioOffice 2008. Its fluorescence in solid state and in solution was measured to confirm the role of hydrogen bond in the structure.

Abstract: Hollow carbon fibers were coated with Fe by chemical deposition to improve their electromagnetic performance. A parallel experiment was designed to investigate their chemical reactivity and surface curvature. The microstructure, composition, phase analysis and electromagnetic performance of Fe-coated and uncoated hollow carbon fibers were studied using SEM, EDAX, XRD and vector network analysis. The result indicates that magnetic loss is introduced due to the inherent property of iron. The real and imaginary parts of the complex permeability (μ′ and μ″) of the composites, which consist of the paraffin and the coated fibers after pretreatment and surface activity, are 1.44 and 0.54 at 2 GHz, respectively.

Abstract: Anti–reducing effect of CaO in barium titanate based ceramic materials sintered at reducing atmosphere and the structure development of the materials has been studied in this paper.The results show: Addition of CaO in barium titanate based ceramic will keep resistivity of the sample sintered at reducing atmosphere at a high level. The resistivity of the materials increase with the increasing of CaO, and the resistivity keep in constant after the amount of CaO excess 3mol%. In the sample with sintering aid of SiO₂ and BaO-excess, introducing of CaO may improve the resistivity of the materials obviously. A slight new phase formation was found in the BaO-excess sample, but no new phase formation was found in the non BaO-excess sample. If there is sintering aid of SiO₂ in the sample, CaO may accelerate liquid phase film formation at the surface of grains, which will suppress the diffusion of oxygen in the grains to the environment.

Abstract: In order to study the sludge microstructure and dewatering performance, the sludge was treated using different conditioners, the same conditioner in a different dosage, the same formula in a different proportion and different order of adding conditioners. The microstructure of dehydrated sludge was observed by scanning electron microscopy. The relationship between the sludge dewatering properties and microstructure characteristics was discussed. It was proven that the different dehydration performance correspond to the different morphology. The better dewatering performance shows more pore at the surface of sludge cake.Contractly, the sludge cake with poor dewatering perform a dense surface, even membranous. Therefore, there is a certain of relationship between the microstructure of sludge cake and its dehydration performance.

Abstract: A nitrite sensor based on a gold particles/polyaniline modified glassy carbon electrode (Au/PAni/GCE) was devoped by electrochemical method. The electrocatalytic oxidation of nitrite at Au/PAni/GCE was studied by cyclic voltammetry. The experimental parameters were optimized, and a voltammetric method for determining nitrite was developed. In phosphate buffered solution(PBS) of pH 3.0, the oxidation peak current of nitrite is proportional to the concentration of nitrite over the range of 4.0×10^-7～5.0×10^-3mol/L with the detection limit of 2.0×10^-7mol/L (r=0.9992). The presented methods of determing nitrite exhibited high sensitivity and good reproducibility.

Abstract: To obtain the microencapsulated electric ink with good display properties, the bare TiO₂ nanoparticles were modified by stearic acid (SA), and the white encapsulated electric ink was prepared by complex coacervation using Gelatin/gum arabic (GA) as wall materials. The bare and modified TiO₂ nanoparitcles were characterized by SEM. Moreover, the fiber-optic spectrometer was also used to measure the reflective properties of the two particles. It was shown that the aggregation phenomena can be greatly decreased by surface modification, and also that the reflective properties can be maintained by this method. Finally, the particles in microcapsules possessed reversible response to dc electric field, and the response time was ~150 ms.

Abstract: Steel cord has the higher technical requirement in the production of wire rod. And the higher requirement of the structure uniformity brings about the more difficulty for producing wire rod. Therefore, the procedure of rod for steel cord has been studied at Anyang Iron & Steel Group Co., Ltd. It has been investigated the low-cost production process, inclusion control, composition segregation, chemical composition control, structure performance control and application of LX70A rod for steel cord. The present research has significant value for the application of similar products.

Abstract: An improved strontium-based aerosol fire extinguishing agent with potassium additives was fabricated, which was followed ‘oxygen balanced’. A series of extinguishing tests showed that the fire extinguishing efficiency of the agent was improved relative to a commercial sample. The results of secondary damage tests indicated that the alkalescence of solution which absorbed solid particles generated by the agent rose a little. The corrosion resistant of copper in the aerosol was better while the iron was available with corrosion to some extent.

Abstract: An energy-saving and high-efficient powder Al and Si codeposition process was employed on 1045 steel, the new technology was mainly based on applying direct current field (DCF) with proper parameters between the treated samples and the powder. The microstructure, thickness and the phase constituents of the coating were analyzed by OM and XRD. The high temperature oxidation resistance for a total duration of 120h and the corrosion resistance in 10% H₂SO₄ for 8h were investigated. The results showed that DCF could lower heating temperature and accelerate the diffusion rate. The phase of the coatings with DCF was composed of Al_0.7Fe₃Si_0.3 and AlFe_3. The treated samples had good high temperature oxidation resistance and corrosion resistance in 10% H₂SO₄ solution.

Abstract: The europium(III)-benzoic acid(HL)-1,10-phenanthroline(phen) complex was synthesized in the ethanol-H₂O system by a precipitation method. The morphology of the minicrystal complex with diameters of ca. 1.0 µm is characterized by scanning electron microscopy (SEM). Elemental analysis and inductively coupled plasma-atomic emission spectroscopy (ICP-AES) are used to determine the chemical composition of the complex. Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction analysis (XRD) are used to examine the structure of the complex. The results show that the complex is a new kind of crystalline complex and the composition of the complex is speculated to be EuL₃(phen). The thermogravimetric curve (TGA) analysis indicates that the complex is stable below 232 °C in air. The photoluminescence analyses (PLA) exhibit that the complex emits the characteristic red fluorescence of Eu (III) ions at 613nm under ultraviolet light excitation.