Advanced Materials Research Vols. 430-432

Abstract: To isolate capsaicin effectively, molecular imprinted polymers (MIPs) with capsaicin were synthesized with methacrylicacid (MAA) as function monomers, ethyleneglycol dimethacrylate (EGDMA) as cross linker by non-covalent method. Technological parameters for the preparation of MIPs were optimized by L9(34) orthogonal test. The static equilibrium binding and recognition properties of MIPs to capsaicin were also investigated. The surface structure of the MIPs was visualized by scanning electron micrography. The results show that the optimistic composition of MIP is as following: 0.25 mmol capsaicin, 7.0 mL acetonitrile, 3.0 mL ethylether, 1.25 mmol MAA and 100 μL 80% tween-80. The adsorption isotherms indicates that the MIPs show a good imprinting effect (QMIPs=23.44 mg/g). The MIPs have the specific recognition selectivity for capsaicin in the mixture. Thus, compared with zingerone and piperine which are similar in molecular structure and property to capsaicin, the MIPs show a good selectivity and intense recognition of the template molecule.

Abstract: Wave-absorbing properties of ordinary concrete and pumice lightweight aggregate concrete which contained expanded perlite and carbon black were investigated in this paper. The results indicated that pumice lightweight aggregate concrete had ideal wave-absorbing properties. Within the scope of 2 ~ 18 GHz, the lowest reflectivity reached to -20 dB and better than the bandwidth of -5 dB up to 9 GHz. Meanwhile, the incorporation of proper carbon black absorber and expansion perlite can improve wave-absorbing properties.

Abstract: The effect of ultrasonic etching on the crystalline structure, fibrillar structure, skin-core structure of stabilized PAN fibers was studied by XRD and SEM. It has been found various degree of decrease occurs in the crystallite size and crystallinity of fibers heated at different temperatures after ultrasonic etching. Fibrillar structure of fibers heated at 195°C~245°C appear after ultrasonic etching in 90wt% DMSO solution for 6h. When the stabilization temperature is over 245°C, no separated fibrils or macrofibrils are found. When stabilized fibers were etched in pure DMSO, skin-core morphology was observed for the fibers heated at 235°C~265°C. The method of ultrasonic etching using pure DMSO confirms the structural difference between the skin and the core, also makes the difference visual.

Abstract: In this paper, based on the liquid forging part flange LY12, the influence of specific pressure on the organization and performance of the liquid forging part was studied through microstructure, mechanical properties and tensile fracture surface analysis methods, this article also has some guiding significance to the formulation of the best liquid forging process parameters. The results show that the tensile strength, hardness and elongation of the parts raise with the specific pressure increasing, the organization has also been significant refinement and improvement.

Abstract: The sludge dramatically causes the water pollution and storage reduction of a reservoir, threatening its functionality and operational life span. One strategy is to add sludge into lightweight concrete, thus, recycling the sludge and making it one of the valuable natural resources. This study intends to use the Design of Experiment (DOE) and Taguchi Method to ensure the stability of quality and to reduce the production cost of lightweight concrete using the sludge kilned coarse aggregate from the Shihmen reservoir in Taiwan. Based on literature reviews as well as past experimental results, the research selects four control factors including lightweight aggregate unit weight, water content, water-binder ratio (W/B), and interactions among these factors. By using Analysis of Variance (ANOVA), this study discusses the significant degree of these control factors and their interactions, affecting the quality characteristics of lightweight concrete such as compressive strength, ultrasonic wave, and electric resistance at different ages. The significant levels and contribution ratios from each ANOVA analysis are placed in a Cross Table to obtain the overall evaluation, giving the optimal mix proportions. On the basis of the results, the optimal parameter setting are: the unit weight of lightweight aggregate at 0.378 g/cm³, the water consumption at 160 kg/m³, and the water-binder ratio at 0.28 for the 14 and 28-day age lightweight aggregate concrete, and the unit weight of lightweight aggregate at 0.378 g/cm³, the water consumption at 140 kg/m³, and the water-binder ratio at 0.28 for the 91-day age. Furthermore, considering the mean and variance, the research find out the optimal design according to the combination of ages and quality characteristics using the Type III Signal to Noise Ratio of Taguchi’s nominal-is-the-best quality characteristics. The obtained result includes the unit weight of lightweight aggregate at 0.378 g/cm³, the water consumption at 160 kg/m³, and the water-binder ratio at 0.28.

Abstract: In Situ iron nanoparticles can be formed during copper alloy solidification. Here we consider ZCuSn3Zn8Pb6Ni1FeCo alloy.It is noted that high undercooling is the motive power of nanoparticles during solidification , which would act as heterogeneous nuclei to achieve outstanding contribution for grain refinement compared to ZCuSn3Zn8Pb6Ni1 alloy. Convection of the melt inhibit the growth of nanoparticles by way of prohibitting the deposition of iron atoms on the surface.This technique offer new enlightenment for the control of in-situ nanoparticles formed during alloy solidification,and also opens the door to a new class of dispersed nanoparticles strengthened materials.

Abstract: The fiber reinforced concrete with flexible fiber and rigid fiber respectively added into C30 plain concrete, curing under standard condition for 28 days, was used for fatigue resistance performance experiment. The flexible fiber is American Dura fiber and Chinese nylon fiber. The rigid fiber is Chinese steel fiber. The fatigue resistance property was evaluated by the residual strength after 400 thousand times fatigue damage. The result shows that the residual strength of C30 plain concrete was only 35.0% of initial value, but the residual strength of C30 fiber reinforced concrete still remained 75%~90% of initial value. The residual strength of steel fiber concrete, Dura fiber concrete, nylon fiber concrete, is respectively 2.5, 2.3 and 2.1 times of the plain concrete. The fiber reinforced concrete improves the fatigue resistance property compared with the plain concrete. The fatigue resistance ability of flexible fiber and rigid fiber reinforced concrete is close to each other.

Abstract: Fe₃O₄ ferrite nanoparticles used for preparation of PE composite have been prepared by chemical co-precipitation method and modified by different methods. And the nanoFe₃O₄/LDPE composite materials with different mass percentage concentration of 0.25 to 1 percent were prepared by melt blending. The relationship of permittivity and dissipation factors dependence of frequency were investigated by Broadband Dielectric Spectrometer made by novo-control company. Through these measurements we got the conclusion that both the doping of Fe₃O₄ and magnetization have effect on permittivity and dissipation factors, and the effect relates to the doping methods and quality percentage content.

Abstract: Carbon fibers (CNFs) were surfacial metallized by electroless deposited with nickel, and their field emission properties were investigated by diode test. The results indicated that the CNFs owned better field emission properties after electroless depositing nickel for 30 min, with nickel metal thickness as 3.25 µm and the volume resistivity down to 1.3510-4 Ω•cm. The morphology and composite of Ni-coated CNFs were characterized by scanning electron microscope (SEM) and X-ray diffractions (XRD), respectively. The results indicated Ni-coated CNFs were amorphous and had better surface. The field emission tests showed when applied voltage was 832V, Ni-coated CNFs appeared bright dots, and the high luminance achieved 988cd/m2 under applied voltage 1456V.

Abstract: The carbon counter electrodes for Dye-sensitized solar cells (DSSCs) were deposited on FTO glass using graphite target by bipolar pulse magnetron sputtering. The effects of sputtering pressure on the structures and properties for carbon films were investigated. The carbon bond structure was analyzed by Raman spectra. The sheet resistance of carbon film was detected by four-probe tester. The transmittance was tested by UV-visible spectrum. The performance of DSSCs was tested by solar simulator after the cells assembled. The results indicated that the ratio of ID/IG reduced, the degree of graphitization decreased, sheet resistance raised, transmittance increased and photoelectric conversion efficiency reduced with the increasing of sputtering pressure.