Advanced Materials Research Vols. 998-999

Abstract: Fine Chemicals is an important direction and inevitable trend of development of China's petrochemical industry. In order to occupy the commanding heights of industry development strategy, many domestic chemical companies enhance their ability to resist risks, fine chemical products to take extended strategy. However, due to the fine chemicals own characteristics, while enterprises is in product extension, they are often faced with complex decision problems. Based on all of those, multi-product programs projects preferred aand the main product of the extension when siting evaluation are research.

Abstract: Metal rubber is a new type of elastic damping material. It’s often used in all kinds of instruments and equipment to vibration isolation and buffer. The internal of metal rubber is mesh structure in space formed with wires. The contact points of the crossed wires aren’t solid collusion. Although the compressive strength of metal rubber is very good, but the structure of metal rubber would become loosly and destroyed under tensile load. Literature [1] put forward that the pulse discharge sintered to metal rubber can make the contact point transform to solid collusion. The method is based on the theory of resistance welding to the contact points between sintering metal wires in metal rubber. The research and analysis to the electricity characteristics of the metal rubber has important significance to optimize parameters of electrical pulse discharge experiment and improve the quality of sinter.

Abstract: With sugar as an addition, the active carbon released from sugar can lead to the effective carbon doping in MgB2 superconductors only under the condition of high temperature sintering. However, this kind of carbon doping cannot occur at low temperature sintering condition. The reason is that the carbon released from the decomposition reaction of the sugar added in MgB2 has very low chemical activity during low temperature sintering process, which is similar with the results of elemental carbon or graphite doping directly. Thus, only the sintering temperature reaches a certain temperature or more (generally greater than 700oC), the carbon can possess sufficiently high chemical activity and go into the lattice of MgB2 to replace the B. In the condition of low temperature, it is difficult to form an effective carbon-doped.

Abstract: Three biodegradable amphiphilic triblock copolymers: polylactide-poly (ethylene glycol)-polylactide (PLA-PEG-PLA), poly (ε-caprolactone)-poly (ethylene glycol)-poly (ε-caprolactone) (PCL-PEG-PCL) and poly (lactide-glycolide)-poly (ethylene glycol)-poly (lactide-glycolide) (PLGA-PEG-PLGA) were synthesized. Their chemical structures were characterized. In aqueous solution, their self-assembly and degradation were studied by dynamic light scattering (DLS) and transmission electron microscopy (TEM). Spherical micelles were formed in aqueous solution via self-assembly of the amphiphilic triblock copolymers. After degradation, the PLA-PEG-PLA and PCL-PEG-PCL micelles became smaller and the PLGA-PEG-PLGA micelles change to vesicles, which should mainly attribute to their different degradation speed.

Abstract: An aryl benzyl ester dendritic axially substituted silicon (IV) phthalocyanine, a di-{3,5-di-(4-methoxycarbonyl group benzyloxy) benzyloxy) benzyloxy} axially substituted silicon (IV) phthalocyanine (DSiPc) was synthesized. Its structure was characterized by elemental analysis, ¹H NMR, IR and ESI-MS. The photophysical property of DSiPc was studied by steady and time-resolved spectroscopic methods. The steric hindrance of dendritic structure can reduced the aggregation efficiently. The photoinduced intermolecular electron transfer between this novel macromolecule and benzoquinone was studied. The results showed that the fluorescence emission of this dendritic phthalocyanine could be quenched by BQ. Therefore, this novel dendritic phthalocyanine was an effective new electron donor and transmission complex could be used as a potential artificial photosynthesis system.

Abstract: Temperature monitoring was done on microwave curing of epoxy resin system consisting of di-glycidyl ether of bisphenol-A(DGEBA) E-51 and curing agent 4,4’diamino-diphenyl-methane (DDM). The study shows that microwave curing of epoxy resin system is an exothermic reaction and the temperature variation during microwave processing has the obvious characteristics of “temperature increment - heat release - temperature falling”. Analysis on the infrared thermal images indicates that each moulding body has its own temperature distribution and differs from others. The non-uniform temperature distribution reveals the uneven electric field distribution in the domestic microwave oven.

Abstract: Scatterer is the basic element of photonic crystal. With operating frequency f =1THz (wavelength λ =300μm), we proposed sector as scatterer and analyzed the influence of parameters to photonic bandgap (BPG) for the structures of pillars in air, such as the center radius of sector r, width of sector d, and central angle of the sector θ. For two-dimensional hexagonal arrays, the absolute BPG width and the relative BPG width were demonstrated by the three parameters in TE mode, respectively.

Abstract: Using melamine formaldehyde (MF) microspheres as hard templates and silica colloid as shell precursors, core-shell structures of silica-coated MF microspheres were prepared by the electrostatic adsorption process or spray drying inspired in-situ coating and drying process. Furthermore, nanometer- and micrometer-sized silica hollow spheres were obtained by calcinations in air. The influence of preparation methods and ratio of silica colloid to MF microspheres on the composition, the morphology and size of the core-shell intermediates and the hollow spheres were studied with FTIR, SEM and TEM techniques.

Abstract: Polyaniline (PANI) nano-thin films were deposited on a novel microstructure silicon (MSS) substrate via in-situ self-assembly approach for NH₃ gas-sensing. The MSS was prepared by alkaline etching process, and gold interdigital electrodes were formed on the MSS surface by vacuum evaporation. The characterization of the MSS and PANI nanothin film were investigated by scanning electron microscope (SEM) and UV-Vis absorption spectroscopy. SEM images showed that the MSS exhibited an orderly uniform hemisphere array structure, and the MSS surface was covered by a compact PANI thin film which consists of PANI nanoparticles and PANI nanofibers. The gas-sensing properties of the sensor were examined at room temperature. The results revealed that the sensor exhibited a good response and recovery characteristics to NH₃.

Abstract: sp² rich carbon films were produced by using magnetron sputtering deposition. The hardness, friction coefficient and wear volume were elevated by Knoop micro-hardness and pin-on-disk tester; The composition and microstructure of the carbon films have been characterized in detail by combining the techniques of Rutherford Backscattering Spectrum (RBS), X-Ray Photoelectron Spectrum (XPS) and X-Ray Diffraction (XRD); the electrical resistivity was measured by Four Probe Methods (FPM). It is found that: the films hardness are 11~17GPa (HK0.05), the friction coefficients are 0.1-0.2, the wear rate is 10-15m3/Nm; The maximum intensity position in the C1s indicates the chemical bonds are mainly sp²; the electrical resistivity is 1~2×10^-4Ω·m. XRD proves these carbon films are amorphous.