Advanced Materials Research Vols. 750-752

Abstract: Isothermal crystallization behavior of PET/PTT-CNTs composites was investigated by DSC. The Avrami equation was employed to describe the isothermal crystallization process. The change of the half-time of crystallization t_1/2 suggested that the addition of CNTs in the composites can accelerate the overall crystallization process.

Abstract: Characterizations of a liquid polycarbosilane used as SiC matrix precursor were investigated by TG-DTA, FTIR, XRD, etc, which indicated the feasibility of using LPCS as precursor for CLVD process to prepare C/SiC composites. The results show that the inorganic conversion of LPCS to SiC is almost completed at 900 °C, and the crystallization of β-SiC appears at 855 °C approximately. As the temperature increases, the deposit becomes more pure and the crystallinity of β-SiC also increases. The atomic ratio of C/Si in the deposit attained at 1200 °C is near-stoichiometric, the crystallite size of β-SiC is about 33.4 nm.

Abstract: The silica/polyacylate composite latex was prepared via miniemulsion polymerization. Fluorinated acrylate monomer was used the co-stabilizer and hydrophobic modifier. The effect of fluorinated acrylate on stability of the composite latex was compared with the traditional co-stabilizer. The composite latex and the resultant film were characterized by Fourier transformation infrared spectroscopy, Dynamic laser scattering, Water contact angle. Fluorinated acrylate can stabilize the miniemulsion polymerization as the co-stabilizer and the resultant film has good durability of hydrophobicity under high moisture environments.

Abstract: Microstructures of sisal fibres were revealed optically. Statistics on dimensional parameters for sisal fibres were used to establish a geometrical model in order to estimate the elastic modulus and moisture absorption capability of sisal fibres. The single fibre tensile test was conducted on the sisal. The predicted longitudinal modulus and water absorption was in good agreement with experimental results. It was found that the lumen ratio is a significant factor in determine the mechanical properties of the natural fibre.

Abstract: This review reports recent advances in the field of polymer/kaolinite nanocomposites. These materials are attracting considerable interest in polymer science research because they exhibit dramatic improvement in properties at very low filler contents. The structure of kaolinite is displayed and approaches to expand the basal spacing of kaolinite are given. In addition, the preparation of polymer/kaolinite nanocomposites is summarized. Part of the review also concentrates on the improvement of mechanical property, thermal stability, gas permeability and other properties of polymer/kaolinite nanocomposites, and detailed examples are also drawn from the scientific literature. The prospect of the study on polymer/kaolinite nanocomposites is elaborated.

Abstract: In the present paper, the WO₃ nanoparticles were fabricated via a hydrothermal treatment. The products are characterized in detail by multiform techniques: transmission electron microscopy, X-ray diffraction. The results show that products are WO₃ nanoparticles with diameter of about 100-150 nm. Electrochemistry properties of the prepared WO₃ nanoparticles was characterized by cyclic voltammetry. Cyclic voltammetry results indicate that WO₃ nanoparticles exhibits a remarkable electrochemical activity for hydrogen intercalation. The reason for electrochemical activity of WO₃ nanoparticles is attributed to the formation of H_xWO₃ by hydrogen intercalation/de-intercalation into/out of the tungsten oxide.

Abstract: In this paper, non-woven micron-nanofiber mats of PLLA were successfully prepared via electrospinning technique, and the mats were characterized by SEM, their degradation performance was studied too. The results indicated that PLLA fibers have Bead-string morphology and the surface morphology changed to porous after degradation.

Abstract: Poly (vinylidene fluoride) (PVDF) / poly(methyl methacrylate) (PMMA) composite membrane was produced by the electrospinning technique. Thermal treatment was introduced to improve the mechanical property and dimensional stability. In this paper, the PVDF/PMMA membranes before and after thermal treatment were characterized by Scanning electron microscope (SEM), differential scanning calorimeter (DSC) , pore size and porosity test, electrolyte uptake test and tensile test. The pore size, porosity, electrolyte uptake rate, tensile property, as well as melting temperature and crystallinity changed with the treated temperature. The results show that thermal treatment could notably increase the tensile property of electrospun PVDF/PMMA composite membrane and 160°C is a proper temperature for thermal treating.

Abstract: The synthesis used urea and Zr (NO₃)₄·5H₂O as material to prepare tetragonal-ZrO₂ nanocrystals through microwave-induced combustion process. The tetragonal-ZrO₂ nanocrystals were characterized by X-ray diffraction (XRD). The effect of Zr⁴⁺/urea molar ratio on the synthesis of tetragonal-ZrO₂ were studied. It was found that tetragonal-ZrO₂ crystal would be better when the Zr⁴⁺/urea molar ratio was larger than 1:3.The SEM images of the samples showed the hollow structures formed at different levels of molar ratio of Zr⁴⁺/urea. This method is a simple but effective route to prepare tetragonal-ZrO₂ nanocrystals.

Abstract: Large area carbon nanotubes array were synthesized on the quartz glass by a simple chemical vapor deposition. Scanning electron microscopy and transmission electron microscopy were used to evaluate the morphology and structure. The results show that the well-aligned arrays are synthesized and their length can reach millimeter range, these CNTs have varying outer diameters from 20 to 70 nm and display hollow tubular structures.