Advanced Materials Research Vols. 785-786

Abstract: In this paper, the rare earth cobaltite Nd_1-xSr_xCoO₃ (0.1≤x≤0.5) samples were prepared using conventional solid state reaction method. Magnetization and spin state of cobalt of sample were systematically investigated. The experimental result suggests that magnetization and the Curie temperature increase sharply with increasing Sr content. The Curie-Weiss fit shows that most of the Co³⁺ ions are in the intermediate spin state and the Co⁴⁺ ions are in low spin for x=0.5. Furthermore, our study confirms that spin-state transition take place in Nd_1-xSr_xCoO₃.

Abstract: In order to obtain a novel liquid crystal compound with trifluoromethyl substitutent, Sonogashira coupling reaction was used to synthesize the mesogenic compound based on tolane. Firstly, 1-iodo-4-trifluoromethyl-benzene was modified with acetylene groups, and then coupled with iodo amyl biphenyl through Sonogashira reaction to obtain the target compound. Moreover, the liquid crystal phase behaviors including transition temperatures and phase sequences were investigated by DSC and POM.

Abstract: We investigated the magnetization switching process in a bilayered exchange spring system through micromagnetic simulations. A typical exchange coupled magnetic hysteresis loop was observed in this work. The influence of magnetocrystalline anisotropy constant on the magnetization of the exchange spring structure was also studied. It is demonstrated that the film thickness of hard layer play a more important role than that of soft layer to the influence on coercive field and shape of the hysteresis loop.

Abstract: The liquid crystal material with trifluoromethyl substitutent is a very important liquid crystal monomer to combine mixture in the application of display area. In this paper, a kind of liquid crystal material with trifluoromethyl substitutent was synthesized by traditional method of Sonogashira coupling reaction, the reaction mechanism and reaction conditions were then obtained. In addition, the synthesized compound was characterized by FT-IR and ¹H-NMR to confirm the consistent structure with target compound.

Abstract: This paper reviews the emerging applications of mesoporous silica materials to be as adsorbents for heavy metals removal from the wastewater. Functionalization of the ordered mesoporous silica with organic or hybrid function groups provides new opportunities for fine-tuning the chemical, physical and mechanical properties of these novel materials. This has led to an interest in application of these materials as effective and low-cost adsorbents for removal of heavy metals, such as Pb (II), Cu (II), Hg(II), Cr (III), Cd (II) and Ni (II).

Abstract: Bi_0.9Pr_0.1Fe_1-xTi_xO₃ ceramics were prepared by a rapid liquid sintering method. The structure of samples was confirmed by X-ray diffraction and scanning electron microscopy. Ti substitution leads to some changes in the crystal structure of Bi_0.9Pr_0.1FeO₃, which also significantly affects the dielectric constant and loss.

Abstract: The γ-LiAlO₂: Cr³⁺ ceramics were successfully fabricated using multi-mode cavity microwave furnace, and the samples absorption spectrum was measured at room temperature. There are five bands in the red and near-infrared region. Using the crystal-field theory and introducing the average covalent factor model, we calculated the energy-level splitting of Cr³⁺ ions in γ-LiAlO₂ and successfully explained these bands. These calculation results are in good agreement with the optical experiment data.

Abstract: It is studied that influence of Li vapor transport equilibration (VTE) on surface refractive index of congruent Mg (4.5 mol%):LiNbO₃ crystal at wavelength of 1536 nm. The results show the ordinary index n_o decreases when t < 40 h, then recoveries slightly and tends to a constant when t >100 h. The extraordinary index n_e has the VTE effects as similar as n_o, but the alteration amplitude is smaller than n_o. The secondary ion mass spectrometry) study shows that the VTE induces Mg diffusion within the crystal in an inhomogeneous Mg depth profile, depending on the VTE duration. The neutron activation analysis shows that the VTE hardly induces Mg evaporation away from the crystal. First, the Mg ions of crystal internal diffused to the surface in the early stage of VTE, and then they diffused slowly back into the bulk of the crystal toward equilibrium when Li concentration tends to equilibrium.

Abstract: In this paper, several nonwoven and woven clothing are be selected for tested their protective, strength and comfortable. Through analysis their properties, the result can be seen that the nonwoven fabrics have better protective properties than woven fabrics, especially PVA nonwoven through water resistance finish. So, varies nonwoven clothing is used in hospital and family protective daily.

Abstract: An intumescent flame retardant (IFR) containing phosphorus and APP was applied to polyester fabric. The finishing process was optimized and the properties of treated fabric were characterized. The optimum process was as follows: the total dosage of IFR system was 40%, the mass ratio of phosphorus-containing flame retardants and APP was 7:3, and curing temperature was 180°C. The treated PET fabrics imparted good resistance to melt drop. Characterization of the thermo-gravimetric analysis, differential scanning calorimetry (DSC) indicated that much more residual char with intumescent structure, the incombustible gas and water were formed during combustion of flame retardant polyester fabric, whose decomposition temperature was lower compared to that of the untreated sample.