电化学聚对苯膜的现场ESR及其性能研究

本文用现场电化学-ESR联合测试的技术, 对电化学聚对萃膜在浓H_2SO_4中的性质进行了研究, 结果表明: 聚对苯膜具有高的电导率和相对低的自旋磁化率, 极化子与偶极化子为主要导电者, 并在一定的电位下相互转化, 自旋粒子有很大的离域性。膜中链与链之间可能存在部分的氧桥结构, 而引起体系结构的某些变化, 使聚对苯膜的电导提高以及掺杂容易进行。掺杂量受电位控制, 浓H_2SO_4中的HSO_4~-嵌入/脱嵌的电化学可逆性很好, 最大掺杂量可相当于每5个苯环单元氧化出一个正电荷, 可望将电化学聚对苯用作稳定的二次电池电极材料。

IN-SITU STUDY ON ESR SIGNAL AND PROPERTIES OF POLYPARAPHENYLENE BY ELECTROCHEMICAL POLYMERIZATION

The conducting polymer, polyparaphenylene (PPP), can be electrochemically polymerized in concentrated sulphric acid. The iu-situ ESR experiment shows that the PPP film possesses high conductivity and low spin susceptibility. Polarons and bipolarons are the main conducting species and interchange each other according to the electrode potential.The unpaired spins are highly delocallized.There may be some interchain O-bridges existing in the PPP film. The bridged structure may produce a space effect, which make the film easily doped and increase the conductivity through interchain charge hopping. In conc. H_2SO_4, the electrochemical intercalation of HSO~-_4 ions is reversible. The doping capacity can be as high as 22%, implying one positive charge in every 5 benzene units. It is possible to use this polymer as stable electrode material for secondary battery.