Materials Science Forum Vols. 610-613

Abstract: The Melt spinning technique of Nano Zinc Oxide/PP/PLA composites filaments fabricated by plasma treated Nano Zinc Oxide（NZOP） was studied in the present investigation. The experimental results showed that the physical and mechanical properties of Nano Zinc Oxide/PP/PLA composites filaments depended on the following factors of the percentage of NZOP, the percentage of maleic anhydride (MAH), the plasma treatment parameters, helium gas flow rate, output power, sample treatment or stationary time and oxygen gas flow rate. Among them the oxygen gas flow rate had the significant influence on the filament properties of tensile modulus, the yield strength, the melting temperature and the crystallization temperature. Stepwise multiple regressions orthogonal design method of system optimization was used to determine the percent of contribution of each factor. It was found that the four indicators were different by these analyses. The experimental results indicated that the optimized conditions by stepwise multiple regressions were better than that by traditional analysis.

Abstract: The bioavailability of trace metals in sewage irrigated soils in the southeastern suburbs of Beijing, China was examined by using in vitro digestive fluid extraction method. A sequential chemical extraction (SCE) procedure was used to measure the speciation of trace metals in soil samples, including Cd, Pb, Cu, and Zn. The average concentrations of Cd, Pb, Cu, and Zn were 2.23, 37.9, 59.9, and 127.0 mg kg-1, respectively, indicating that the heavy pollution of soils was caused by Cd, Cu, Pb, and Zn which were mainly distributed in the residual phase, whereas Cd was mostly in the carbonate phase. The extraction efficiencies of Cd, Pb, Cu, and Zn quantified by the in vitro digestive fluid extraction method, were lower than those by the SCE procedure, and the extraction efficiencies of both methods followed the same pattern: Cd >Zn>Pb>Cu. The amount of trace metals extracted by using these two methods were positively correlated. Therefore, the in vitro digestive fluid extraction method can be used to examine the bioavailability of soil-bound trace metals.

Abstract: Poly(vinylidene fluoride)(PVDF) is photochemically stable even in the presence of TiO2 and Pt nanoparticles, and poly(methacrylate)(PMMA) has good solvent retention. The quasi-solid electrolytes based on PVDF-PMMA blend polymer were prepared in this work by soaking a porous membrane in an organic electrolyte solution containing the I−/I3− redox couple. The as-prepared electrolytes were characterized by means of Fourier Transform Infrared Spectroscopy, Scanning Electron Microscope respectively. Moreover, the conductivity and the voltage-current curves of the electrolytes were measured by electrochemical workstation. The results indicated that the optimum blend proportion of PVDF and PMMA was 6:4. The porous structure prepared with the addition of propanetriol was beneficial to ion diffusion and thus enhanced the conductivity of the electrolytes. The gel polymer electrolyte had a conductivity of 0.14 mS•cm-1 under the ambient atmosphere. Furthermore, electrolytes were assembled to fabricate DSSCs and the performance of the cells was tested. The good properties with the open-circuit voltage of 0.60V and the short-circuit current of 1.1mAcm-2 were achieved upon illumination with visible light.

Abstract: Low-temperature plasma deposition of diamond-like carbon (DLC) and gallium nitride thin-films grown on Si substrate by PECVD was investigated using atomic force microscopy and reflectance spectra for photovoltaic devices application. It was found that the morphological features of the GaN film depend on the substrates under the optimum deposition conditions. The optical band gap of the films was approximately 5.5eV for PECVD DLC and approximately 3.3 eV for PECVD GaN.

Abstract: The photovoltaic system with compound parabolic concentrator was designed and fabricated based on the performance of polycrystalline-silicon solar cells with back surface field structure. The performance of the system was investigated on site. The experimental results showed that the effective concentration ratio is to be 2.5 and the output power of the system can be increased approximately by 2 times compared to that of the flat plate system. The prototype modules with CPC can provide a potential possibility in power production application, and can reduce the cost of photovoltaic electricity.

Abstract: A novel cathode catalyst for direct methanol fuel cell, MN4 polymeric cobalt tetrametho -xyphenyl porphyrin (PCoTMPP), was prepared by solvent thermal method. The PCoTMPP exhibited spherical particles with diameter of 0.8~1µm. The spherical PCoTMPP showed a good monodisperse. The oxygen reduction reaction activity of PCoTMPP was examined by CV, LSV and CA methods. The results showed that PCoTMPP has a better oxygen reduction reaction activity and stability in comparison with CoTMPP and leads to a four-electron reduction of dioxygen to water.

Abstract: Boron-doped nanocrystalline silicon film was prepared through plasma enhanced chemical vapor deposition (PECVD) on silicon substrate and glass substrate under the high deposition pressure (332.5-399Pa) and the high deposition temperature (320-360°C). The film was investigated by Raman, electron probe microanalyser, conductivity and mobility experimenting techniques. The conductivity of the boron-doped nanocrystalline silicon film was 2.97×102Ω-1cm-1. The results showed that the interface between the film and the silicon substrate might have quantum spot and small size effect, causing the increasing of conductivity.

Abstract: The tin doped indium oxide (ITO) thin films were prepared by sol-gel dip-coating process from InCl2.4H2O and SnCl4 in alcoholic solutions. The influences of organic ligands, including acetylacetone (AcAc) and diethanolamine (DEA), on the stability and the composition of the sols, and on the microstructure and properties of the thin films have been investigated. It is indicated that a suitable amount of DEA or AcAc helped to keep the stability of the ITO sols, and helpful for the formation of the homogeneous thin films. The TG-DSC and X-ray diffraction analysis revealed that the organic ligands also had effect on the crystallization temperature and crystal structures of the thin films. The thin films with DEA as coordination ligands had a good crystal quality when heated at 450°C. As a result, it exhibited a better electrical property than that with AcAc as stabilizers.

Abstract: Organic photovoltaic(OPV) cells are rapidly gaining attention due to their potential to be fabricated at low cost in thin, flexible, and light-weight forms. For efficient generation of photo-induced charges,C60 has been indispensable electron acceptors in building heterojunctions with various suitable electron donors, such as CuPc, and Alq3 was always used as a new buffer layer to improve the degradation of heterojunction conductivity upon oxygen permeation In this work, the photoelectric properties of organic solar cells(ITO/CuPc/C60/ Al) were studied with a focus on the effect of substrate temperature. All the organic layers and the aluminum cathode were prepared onto ITO substrates by vacuum deposition at various substrate temperatures from room temperature to 363°CK. With increasing the substrate temperature , an improvement in crystallization of bilayer films(CuPc/C60) was observed by AFM. The results showed the photoconduction of the bilayer films increased because the bilayr films were well oriented, and the carrier mobility of the films were enhanced withby the increase of the substrate temperature.

Abstract: TiO2/SiO2 complex nanofilm with high transmittance on solar cell glass was prepared by sol-gel method. Particle diameters, surface structures, the thickness of nanofilm and the transmittance of light from 400nm to 1100nm were tested with AFM, UV2550 and other instruments. The mole percents of TiO2 in SiO2 and their ratio influences on the transmittance of glass, aging ability and other properties of nanofilm were investigated. The AFM photos demonstrated that the TiO2/SiO2 film with high transmittance were composed of nanoparticles with 10nm to 30 nm diameters and their structures were meshes with many holes whose diameters were from 300nm to 500nm. The results revealed that as the mole percents of TiO2 in SiO2 increased the transmittance of solar cell glass with TiO2/SiO2 nanofilm decreased but the aging, adhering and wearing abilities increased and as the diameters of nanoparticles decreased the transmittances of solar cell glass with TiO2/SiO2 nanofilm increased under the condition of TiO2/SiO2 nanofilm with meshes of 300nm to 500m diameters of holes. When the mole percents of TiO2 in SiO2 were 0.1%~0.3%, the average diameters of particles in TiO2/SiO2 nanofilm were about 10nm and the structures of TiO2/SiO2 nanofilm were the meshes with many gaps and the diameters of holes were 300nm to 500nm. The increased transmittances were the greatest about 3.6%, increased value of solar cell efficiency about 3.8% and the aging, adhering and wearing abilities of TiO2/SiO2 nanofilm were best for 20 year life through rapid aging tests.