摘要
在40Hz～11MHz频率范围测量了聚苯乙烯膜以及混入聚吡咯粒子的聚苯乙烯膜和电解质溶液构成的体系的介电谱,发现了特异的弛豫现象:纯的和掺入导电性聚吡咯后的聚苯乙烯膜分别显示出单一弛豫和双弛豫的不同模式的介电谱.在Maxwell-Wagner界面极化概念基础上解释了该弛豫机制:高、低频弛豫分别由膜-液界面极化和膜相本身的不均一性引起的.将体系进行了模型化,并利用Hanai理论方法对谱进行了解析,获得了内部电性质的诸多参数.对不同聚吡咯掺入量的膜/溶液体系的介电测量和解析结果表明,电解质溶液的种类、浓度以及膜中混入聚吡咯的量都影响着膜相的介电响应.这些结论为利用加入导电粒子改善绝缘高分子聚合物的电性质的研究以及制备既具有导电功能又使基体的力学性能得到提高的高分子复合物提供了重要的线索.
Dielectric measurements were carried out for polystyrene （PS）/polypyrrole （PPy） composite membranes immersed in dilute aqueous electrolyte solution over a frequency range from 40 Hz to 11 MHz, some differential dielectric relaxation phenomena were observed： pure PS membrane and the PS membrane interfused with PPy showed different modes of dielectric spectra, one relaxation for pure PS membrane and two relaxations for the PS membrane interfused with PPy, respectively. The dielectric relaxation mechanism was explained by the dielectric theories on Maxwell-Wagner polarization relaxation： the high frequency dielectric relaxation was due to the effects of the interfacial polarization and the lower one was due to the heterogeneous property of the composite membrane. The system was modelled and the phase parameters were calculated using Hanai＇s method. The dielectric measurements for the system with the PS membrane interfused with different contents of PPy in electrolyte solutions and the analysis result indicate that the dielectric response of the membrane was influenced by the variety and concentration of the electrolyte, and the quantity of PPy contained in the composite membrane. These results give a new way of increasing the dielectric constant compared to that of pristine polymer by interfusion with electric particles and offer an important clue to the preparation of macromolecule composite compound with high conductivity and good mechanical capability.
出处
《化学学报》
SCIE
CAS
CSCD
北大核心
2008年第20期2185-2192,共8页
Acta Chimica Sinica
基金
国家自然科学基金(No.20673014)资助项目
关键词
介电弛豫谱
聚苯乙烯膜
聚吡咯粒子
复合膜
电解质溶液
Hanai方法
dielectric relaxation spectroscopy
polystyrene membrane
polypyrrole particle
composite membrane
electrolyte solution
Hanai＇s method
