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聚苯胺(PAn)作为电流变材料具有响应快、屈服应力大的特点,但因其良好的导电性能导致漏电击穿现象发生,为了进一步增加PAn的悬浮稳定性,引入了粉煤灰漂珠(FAFB),BaTiO_3作为经典的电介质材料也引入其中以进一步提高材料的介电性能。采用逐层包覆的思路,利用溶胶-凝胶法在漂珠表面包覆BaTiO_3,获得FAFB@BaTiO_3,再利用原位聚合法制备以FAFB@BaTiO_3为核、PAn为壳的结构复合材料即FAFB@BaTiO_3@PAn。利用FTIR、XRD和SEM对材料的结构与形貌进行分析,借助四探针技术和LCR数字电桥对材料的导电与介电性能进行分析,利用自组装电流变仪进行了电流变特性测试,考察了7d内的悬浮稳定性能。结果表明:BaTiO_3、PAn确实发生了逐层包覆,且电导率、介电常数、介电损耗和剪切应力均符合复合效应规律,介于PAn与FAFB@BaTiO_3之间,其中,剪切应力可达675Pa(电场强度为3.0kV/mm);漏电现象得到缓解,击穿电压提高了20%;比较悬浮稳定性发现,7d后FAFB@BaTiO_3@PAn悬浮率仍为82%。
Polyaniline (PAn) has the characteristics of fast response and large yield stress as electrorheological material, but due to its good electrical conductivity, PAI occurs. In order to further increase the suspension stability of PAn, polyaniline (PAn) FAFB), BaTiO_3 is also introduced as a classical dielectric material to further improve the dielectric properties of the material. BaTiO_3 was coated on the surface of floating beads by sol-gel method to obtain FAFB @ BaTiO_3 by using the method of layer-by-layer coating. FAFB @ BaTiO_3 as the core and FAn shell as FAFB @ BaTiO_3 @ PAn. The structure and morphology of the materials were analyzed by FTIR, XRD and SEM. The electrical and dielectric properties of the materials were analyzed by four-probe technique and LCR digital bridge. The electrorheological properties of the materials were tested by self-assembly rheometer. The suspension stability within 7 days was investigated. The results show that BaTiO_3 and PAn do layer by layer, and the conductivity, dielectric constant, dielectric loss and shear stress are in accordance with the composite effect law, which is between PAn and FAFB @ BaTiO_3. Among them, the shear stress Up to 675Pa (electric field strength of 3.0kV / mm). Leakage phenomenon was alleviated and breakdown voltage increased by 20%. Compared with suspension stability, the suspension rate of FAFB @ BaTiO_3 @ PAn was still 82% after 7 days.