Advanced Materials Research Vols. 197-198

Abstract: A novel NVIS filter based on NIR-dyes and polymer film was prepared through a special designed method. The relation between optical performance and NIR-dye content was discussed. The optical properties of the filter can be easily controlled by changing the amount of NIR-dyes. The results showed there was a good linear relationship between absorbance value and amount of NIR-dyes. Then, a filter with optimal amount of NIR-dyes was prepared. The filter showed strong absorbing ability in the region between 660nm and 930nm. Meanwhile, it showed sufficient transmittance between 400nm and 630nm. At last, an environmental test was taken to evaluate the performance stability of the filter.

Abstract: M(Salen)-functionalized Fe₃O₄ polymer magnetic composites (Fe₃O₄-poly(MMA -DVB-GMA)-M(Salen), where M = Ru(III), Cu(II), Fe(III)) of approximately 20 nm in size were synthesized and characterized by IR, AAS, EA, TGA, XRD, TEM and VSM. These magnetic composites were air-stable, efficient catalysts for the selective oxidation of alcohols to aldehyde and ketones.

Abstract: Superconducting SmFeAsO_0.8F_0.2 compound was successfully synthesized by high pressure high temperature treatment with pressure of 6 G Pa at 1400 °C for 2 hours. The X-ray diffraction pattern of the sample indicates the formation of the tetragonal ZrCuSiAs-type SmFeAsO_0.8F_0.2 with lattice parameters a=3.932 Å and c=8.490 Å. The electrical transport study shows that the sample has a rather high transition temperature Tc of about 52 K, and magnetic field effect on the resistance reveals a rather high upper critical field HC2 of about 65 T.

Abstract: Intergrown superlattice Bi₃TiNbO₉–Bi₄Ti₃O₁₂ (BTN–BIT) and SrBi₄Ti₄O₁₅–Bi₄Ti₃O₁₂ (SBT–BIT) ferroelectric thin films have been prepared on p-Si substrates by sol-gel processing. The precursor thin films are crystallized in the desired intergrown superlattice BTN–BIT and SBT–BIT structures annealed at 700°C. Synthesized BTN–BIT and SBT-BIT thin films exhibited good ferroelectric properties and excellence fatigue endurance. BTN–BIT thin films showed a P_r value approximately 19.1µC/cm² and a memory window of 0.7V. Although a little smaller P_r value and memory window were observed for the SBT–BIT thin films, the squareness of a P–E hysteresis loop was superior to that of BTN–BIT thin films. Also, the SBT–BIT thin films had more excellence fatigue endurance compared with BTN–BIT thin films.

Abstract: The corrosion performance of Ag-Cu-Ni-RE alloys in Na2S has been studied in order to assess the influence of rare earth (lanthanum and cerium) on the Ag-Cu-Ni alloys. Optical microscopy has been used to characterize the microstructures of the samples prior to the electrochemical tests. SEM, EDS and XRD have been used to observe the corrosion morphologies and chemical compositions of the samples. The electrochemical tests has been carried out at room temperature in 0.5, 1and 2% (wt. %) Na2S. The results reveal that the Ag-Cu-Ni-RE alloys exhibit improved corrosion resistance, as well as fine and uniform microstructures. Moreover, surface layers forming on Ag-Cu-Ni-RE alloys exhibit improved protective properties compared to the film growing on the Ag-Cu-Ni alloy. Here, it is also found that when comparing to the dilute Na2S solution conditions, there would be a little decrease of the corrosion rate in 2wt. %Na₂S solution. In addition, Ag-Cu-Ni-La-Ce alloy generally exhibits the best corrosion resistance.

Abstract: In order to improve the hydrophobic property of Polyvinylidene fluoride (PVDF) membrane, in this paper nano-silica was modified by silane coupling agent firstly, then the modified nano-silica mixed with fluororesin，crosslinking agent and thickener to prepare the super-hydrophobic surface coating, finally the surface coating was covered on PVDF membrane. The results showed that the contact angle of the modified membrane was 162°and the sliding angle was 4°. The modified membrane was test by SEM and AFM, the surface coating on the PVDF membrane formed micro/nano-meter structure such as lotus leaves surface.

Abstract: The paper presents the technology of preparation about foamed metal materials, which were prepared by an air pressure infiltration process.

Abstract: An unsymmetrical diarylethene derivative bearing both phenyl and thiophene moieties, in which a methoxyl group was substituted at the para-positions of the terminal phenyl ring, was synthesized. At the same time, its photochromic properties and fluorescence switch were investigated in detail. The results showed that this compound exhibited reversible photochromism, undergoing reversible cyclization and cycloreversion reactions upon alternating irradiation with UV and visible light both in solution and in PMMA film. The fluorescence intensity of diarylethene decreased dramatically along with the photochromism from open-ring isomer to closed-ring isomer upon irradiation with 297 nm UV light in hexane.

Abstract: The compound h-LiMnBO₃ with hexagonal structure and space group of P_-6 was synthesized. This compound displayed a particular electrochemical behavior. In the voltage rang of 0.1-3.0 V at 5 mA/g, the first discharge capacity was around 1420 mAh/g. Cyclic voltammogram indicated that the reductive process took place below 1.5 V.

Abstract: In this paper, microorganism cells (Spirulina platens) were used as forming templates for the fabrication of the helical functional particles with standard shape by electroless silver plating method. The cell form, components and the dielectric properties were observed and analyzed using various tools including optical microscopy, scanning electron microscopy (SEM), energy dispersive spectrometer (EDS) and vector network analyzer. The results indicate that the silver coatings on the surfaces of spirulina platensis cells are continuous and compact. The coating thickness of the cells increases with increasing plating time and load, in turn resulting in the increase of the dielectric constant. Furthermore, when the coating thickness is larger than 0.42μm, the samples exhibit significantly percolation phenomenon, indicating that the cells deposited silver form conductive network or electron tunneling in the composites.