化学氧化法聚吡咯导电性能与导电机理

采用化学氧化法制备了导电聚吡咯(PPy).运用SEM和TEM表征了PPy的形貌,利用四探针技术测试了材料的电导率,对影响其电导率的因素进行了讨论,并对其导电机理进行研究.结果表明,氧化剂用量、反应温度、反应时间、掺杂剂的种类等对最终所得材料的导电性能及结构形态有较大的影响.以苯磺酸钠作掺杂剂,FeCl3/Py摩尔比为1.0,冰浴条件下,反应0.5h所得材料电导率最高,为58.82S/cm,其中以2-萘磺酸为掺杂剂所得PPy微观形貌呈现罕见的纤维状.电导率相对较高的PPy,说明其本身掺杂状况使它在氧化掺杂时随导带和价带间的能级差减小,禁带变窄,载流子移动阻力小;阴离子的掺杂和脱掺杂变得容易,因而电导率高.

Conductivity and Conducting Mechanism of Polypyrrole via Chemical Oxidative Polymerization

Polypyrrole was synthesized by chemical oxidative polymerization.Its morphology was characterized by SEM and TEM,and its conductivity was measured by a four-probe instrument.Influences on its conductivity and conducting mechanism were studied.It was found that the conductivity and morphology are greatly influenced by the amount of oxidant,reaction temperature and time,and the kind of dopants.The conductivity of polypyrrole doped with BSNa was the highest under the condition of molar tation of FeCl3/Py 1.0,for a reaction time of 0.5h in an ice-bath.It was shown that the polymer chain of the fiber PPy-NSA was identical to that of PPy doped with other sulfonic dopants.The higher conductivity of polypyrrole was due to its doping condition,the narrow gap between the conduction band and valence band,the freer movement of current carriers,and the doping-undoping of anions.