Dabing Luo

PVDF-PAn Co-Polymer with High Permittivity Fabricated by Emulsion Polymerization

With eEmploying dichloromethane as solvent, sodium dodecanesulphonate as surface active agent, ammonium persulphate as oxidizer, PAn was introduced into PVDF and co-polymer with high relative permittivity reaching to 280 was obtained by emulsion polymerization. By detecting the structural information and electrical property through FT-IR, XRD, SEM, informations about the co-polymers were presented and in this paper. By adjusting the quantity of aniline in polymerization and the concentrations of protonic acid in the post processing, polymers with different electric properties could bewere compared and analyzed. It was The SEM images and XRD patterns showed the crystallization and microstructure information of the co-polymers in comparison. Particularly, the SEM images showed that the PVDF-PAn co-polymers had homogeneous properties in certain constitute range and as a result of emulsion, spherical PAn-PVDF media was fabricated. After robber mixing procedure at certain temperature, the PAn had a relatively average-fine dissolving in the PVDF, which overcame the difficulty of dissolving PAn oin other substrateance. This ensured the fine property for the matrix material in composites. The XRD pattern showed, wWith the increasing of the introduction quantity of PAn, the crystallization of the entire material complex had been raised greatly.

The Synthesis and Structure of New Perovskite-type Niobate Processed in Millimeter Wave Field

In present paper a new niobate materials Ba 5 Li x Ti x Nb 10-x O 30 were synthesized by doping Li + in the system BaO- TiO 2 - Nb 2 O 5 in millimeter wave field. X-ray diffraction (XRD) quantitative and scanning transition spectroscopy (SEM) analysis were employed to study crystal structure and microstructure of reaction products. It was found that pure products could be obtained at temperature 900°, 8 min which is lower comparing with that by conventional method. The XRD data shown the crystal belongs to tetragonal tungsten bronze structure with space group P4bm. The grain size synthesized in millimeter wave field had smaller size, narrower distribution, better sinter-ability, and without hard agglomeration comparing whit that obtaining from conventional synthesis. At lower temperature Ba 5 LiTiNb 9 O 30 is a tetragonal ferroelectric phase.