Advanced Materials Research Vols. 194-196

Abstract: The properties of wool fibers treated with chlorine (Basolan® 88 and Kroy-resin) were compared with surface modification observed by scanning electron microscopy (SEM), frictional properties and mechanical properties. The changes in surface morphology, frictional and physical properties of the single wool fibers are presented. Coating resin on the chlorinated wool fibers results in a significant reduction in the fiber coefficient of friction[1], as the resin smoothes the protruding edges of the fiber scales. However it increases the directional friction effect (DFE) of the fibers. It is postulated that the DFE may limit the ability of those surface fibers to form fuzz and hairiness of spun yarn could reach the critical height required for pill formation. Meanwhile, the fiber tensile strength may be attributed to pills pulling-off during pills formation, indicating a slowing rate of fuzz formation and consequently pill formation.

Abstract: The double-side Tl-2212 films were fabricated on CeO₂-buffered MgO substrates by dc magnetron sputtering and post-annealing method. The RF magnetron sputtering technology was used to grow CeO₂ buffer layers. XRD and SEM measurements showed that the CeO₂ films on annealed MgO substrates were highly c-axis orientation, and the Tl-2212 superconducting films on both sides had similar morphology and crystalline structure. For both sides of Tl-2212 films, the critical transition temperatures (Tc) were above 106 K, and the critical current densities (J_c) were above 2.2 MA/cm² (77 K, 0 T).

Abstract: It is the tendency to adopt novel soft magnetic materials in planar magnetic components to have much more attractive features. In this paper, the nanocrystal magnetic strip is used to consist of magnetic core of planar inductor. A novel network model for dynamic stray capacitances of planar inductor with matrix structure is presented. The magnetic core is taken into account to be one part of the equivalent circuit of planar inductor in high frequency, and its electric potential is considered to be suspended. To analyze the dynamic stray capacitance accurately, the 3D FEM model is adopted, and the parameters for dynamic stray capacitance of inductor windings are obtained. By equivalent circuit simulation of planar inductor, the impedance feature of planar inductor is obtained. The test results by impedance analyzer verify the dynamic capacitance network model.

Abstract: The soybean protein fibers are processed under heat treatment. The change of the strength, initial modulus and work with the temperature and time are analyzed. The results indicate that the temperature has remarkable effect to the mechanical properties when the temperature is higher than 110°C and the effects of the processed time to the soybean protein fibers is very serious when it is reached 20 minutes.

Abstract: Antimony and tellurium were deposited on K9 glass via direct current and radio frequency magnetron co-sputtering. Antimony telluride thermoelectric thin films were simultaneously synthesized without post treatment. The influence of the sputtering power of Te and annealing of Sb-Te fabricated by magnetron sputtering were investigated. The maximum Seebeck coefficient of Sb-Te film was 212 μV/K which was obtained at the sputtering power of Sb 4W and Te 60W separately. When annealed at 300 °C, the electrical resistivity and Seebeck coefficient of the film are 6.67x10⁴ S/m and 119 μV/K. The power factor increased to the highest value of 9.4×10^-4 W/mK² from 4×10^-5 W/mK² after post treatment of the as-deposited film.

Abstract: Crack-free CdS thin films have been electrodeposited on conductive glass substrate by CdCl₂ and S powder in dimethylformamide (DMF) and mixed organic solvents with appropriate volume ratio at temperatures lower than 100°C. The effects of solvents on the cracks and the photovoltaic property and catalytic property of CdS thin film are investigated. The results show that the crack-free CdS thin films have higher photoluminescence (PL) emission intensity and better photoelectrichemistry and photocatalytic activities for degradation organic dyes of Fuchsin acid, phenol red and crystal violet than thin films with cracks.

Abstract: The surface modification of corn starch and the use of modified starch as reinforcing filler partly replaced carbon black in rubber composites were studied. The surface of starch was modified with 3, 4-2H-dihydropyran and maleic anhydride by grafting reaction in organic solution, that is, the process of etherification and the esterification of the starch. The structure of the ether ester starch was investigated by FTIR, SEM. Based on the results of the mechanical and heat building up properties of composite, it is showed that using modified starch as reinforcement filler filled into the rubber partly replaced CB, the characteristics of high flex life and low heat building up for composite can be obtained.

Abstract: A innovative structure of sandwich composite rectangular plate with dimensions of 350 ×83.5×9.5mm was designed, it was made of unidirectional prepreg of carbon fibre and woven fabric prepreg of carbon fiber as face materials and paulownia as core material by hand lay-up performing and press molding technology for investigating the dynamic performance such as natural frequency and modal shapes. Based on testing the in-plane and out-plane mechanical properties of composite samples reinforced by unidirectional carbon fibre and carbon fiber woven fabric, a ANSYS FEA dynamic modeling was developed. According to the impulse response modal test method, a modal test system was established. The natural frequency test results showed that the minimum natural frequency of sandwich composite rectangular plate is about 616.45Hz which is higher about 27.5% than that of aluminum rectangular plate reinforced by carbon. The modal experiment indicated that the 1st modal shape, 2nd modal shape, 3rd modal shape and 4th modal shape of the sandwich composite rectangular plate were torsional vibration, flexural vibration shape, torsional flexural vibration and double-flexural vibration separately. It was found the calculating precision of FEA dynamic predication was very high, the dynamic predicating results by FEA could provide fundamental data to the optimal design high speed reciprocating sandwich composite rectangular parts.

Abstract: In order to investigate the effect of different reinforcement structure on the dynamic characteristics of sandwich structure composite plates used for manufacturing the high speed reciprocating motion composite components, four kinds of paulownia wood sandwich composite test specimens with dimensions of 350×83.5×9.5mm was designed and made by hand lay-up performing and press molding technology. The woven and 2D braiding fabric prepreg were both selected as top face and inner face materials , respectively, and the carbon fiber woven fabric prepreg was chosen as inner part materials. According to the impulse response modal test method, a modal test system was established. It was found that this kind of sandwich structure composite plate has bigger natural frequency value, it’s minimum natural frequency was about 609.77Hz that could meet the requirement for high speed reciprocating motion parts. The dynamic test results shown that the natural frequency of F2BAF-IUC-CPW sample is higher t about 11.17% at least, selecting 2D integral braiding pipe fabric as top face and inner face reinforced materials could effectively improve the dynamic properties of sandwich composite rectangular plates. The modal experiments indicated that the modal shapes of sandwich composite plate specimen with four kind reinforcement structures were identical, it’s 1st modal shape, 2nd modal shape and 3rd modal shape presented torsional vibration shape, flexural vibration shape and torsional flexural vibration shape, separately, the modal shapes of sandwich composite plate specimen were not obviously affected by reinforcement structure.

Abstract: The waterborne polyurethane (WPU) was synthesized from isophorone diisocyanate (IPDI), polypropylene glycol (PPG), dimethylolpropionic acid (DMPA) and 1,4-butanediol (BDO) under acetone reflux. The cast films obtained from it were characterized by Fourier transform infrared (FTIR), nuclear magnetic resonance (¹H NMR) and differential scanning calorimetry (DSC). The curve of DSC presented a bimodal profile. It showed that the waterborne polyurethane resin degraded obviously at about 305°C and 381°C, which was an endothermic course. The scanning electron microscopy (SEM) micrographs revealed that hexanitrohexaazaisowurtzitane (HNIW) was coated with waterborne polyurethane by means of water volatilization. The impact sensitivity experimental results indicated that the characteristic height H₅₀ of HNIW coated with waterborne polyurethane increased from 25.1cm to 34.2cm. That is, the waterborne polyurethane can decrease the impact sensitivity of HNIW.