Advanced Materials Research Vol. 900

Abstract: The rheological properties of sodium alginate (SA)/agar (AR)/montmorillonite (MMT) solutions were investigated using a rotational viscometer. The dependence of solution apparent viscosity on rotation speed, MMT proportion and solution temperature were researched systematically. Furthermore, the relation of apparent viscosity and micro-structure of the ternary solution was also discussed.

Abstract: Esters of Citric acid and palmityl alcohol were synthesized by esterification reaction under catalysis of cation exchange resin and P-toluene sulfonic acid respectively. The effects of amount of catalyst, ratio of raw materials, reaction time and temperature on the synthesis reaction were investigated . The experimental results showed that optimum of process conditions were 1:1~1:1.5 molar ratio of citric acid and palmityl alcohol, reaction temperature of 130~140°C, reaction time of 2 h. Conversion of palmityl alcohol were all more than 90% under 0.3% dosage using p-toluene sulfonic acid as the catalyst, or 0.5% dosage using 721 cation exchange resin with sulfonic acid type as catalyst. The synthesized product had good surface activity.

Abstract: The structure, properties, synthesis methods and application of siloxane fluorinated polyacrylate polymers,side chain fluorinated silicone polymer and fluoro-silicone block copolymers are discussed. Fluorosilicone polymers has excellent physical property such as low and high temperature resistance, hydrophobic oleophobic property, lubricity etc. It is an advanced material.

Abstract: An effective approach to synthesize methacrylate-based hybrid monoliths was carried out by photopolymerization and the properties of the obtained monoliths mixed with mult-wall carbon nanotube (MWNT) were studied in this paper. The prepared hybrid materials with MWNT in the range of 0-5% total weight of monomers were characterized by Fourier transform infrared spectra, thermo-gravimetric analysis (TGA), and mercury intrusion porosimetry, respectively. Moreover, their porosities were evaluated by the determination of flow rate for different prepared monolithic capillaries. The results showed that the monoliths with more MWNT (1-5%) possessed larger pore sizes between 1-10 μm. The hybrid monoliths have the potential advantages including stronger hydrophobic properties and less resistance for the application of reversed phase liquid chromatography in the micro-column separation.

Abstract: The electrochemical oxidation of o-Aminophenol in the presence o f NaCl for wastewater treatment was studied on Ti/IrO₂-Ta₂O₅ , Ti/IrO₂-Ta₂O_5-SnO₂ and Ti/IrO₂ anodes. The experimental results have shown that the presence of NaCl catalyses the anodic oxidation of o-Aminophenol due to the participation of electrogenerated ClO^- in the oxidation. Analysis of the oxidation products has shown that initially organo chlorinated compounds are formed in the electrolyte.

Abstract: To simulate Electromagnetic wave propagation in anisotropic media, absorbing boundary conditions are needed to truncate the computation domains. Based on the finite difference time domain method in anisotropic medium, the implementation of the modified nearly perfectly matched layer absorbing boundary conditions for truncating anisotropic medium is presented. By using the partial derivatives of space variables stretched-scheme in the coordinate system, the programming complexity is reduced greatly. According to one dimensional numerical simulation analysis, the modified nearly perfectly matched layer absorbing boundary condition is validated.

Abstract: An easy-operation in-situ FTIR cell is designed and used for the investigation of dehydroxylation and pyridine adsorption FTIR study. The dehydroxylation FTIR spectra of MCM-41 indicate that the isolated, geminal, and oxygen perturbed silanol vibrated at about 3745, 3735 and 3520 cm^-1, respectively. Py-FTIR spectra indicate that MCM-41 has none Lewis and Brönsted acid sites while the acid amount and acid strength of AlMCM-41 increase with the decrease of Si/Al.

Abstract: The Ag-Ag₂S-PbS thin films were co-electrodeposited on indium-tin-oxide (ITO) coated glass substrates from aqueous solutions containing 0.01 M AgNO₃, 0.01 M Pb (NO₃)₂, 0.1 M Na₂S₂O₃, 0.02 M ethylenediaminetetraacetic acid disodium salt, and 0.5 M Na₂SO₄. X-ray diffraction (XRD), scanning electron microscopy (SEM), and cyclic voltammetry (CV) were used to investigate the Ag-Ag₂S-PbS thin films. The X-ray diffraction analysis demonstrated the presence of cubic structure of metallic silver, acanthite Ag₂S, and cubic PbS, which is consistent with the CV analysis. The effect of different Ag⁺/Pb²⁺ ratios on the morphology and composition of the Ag-Ag₂S-PbS thin films were also studied.

Abstract: A physical model of magnetron sputtering process was built, the distribution of MgO film thickness on the substrate was deduced, and the data were analyzed by using the Matlab. nanosized MgO thin film was prepared on Si substrate by magnetron sputtering. SGC-10 was used to measure the thickness of MgO thin film. The results of experiment correspond fairly well with the theory. Both experiment and the theory show that the distribution of the film thickness on the substrate is uneven and it is also influenced by the radius as well as the distance between the target and substrate. The physical model provides a theoretical basis for evaluation and estimation of the film thickness.

Abstract: The oil-film bearings are widely used in mechanical transmission due to the good performance. In normal operating conditions, the journal and bearing shell are separated by the oil film, which contributes to the reduction of wear. And the stability and reliability of oil film has a great effect on load capacity. The paper briefly introduces research methods of the load capacity of oil-film bearings and points out some aspects of large oil-film bearings for in-depth study. Then combining dynamic simulation with experimental test on the scaled model of whole machine, a dynamic research idea is presented for large oil-film bearings.