聚吡咯中极化子含量对氨气敏感特性的影响

Effect of polaron content in polypyrrole on ammonia gas sensing performance

采用原位气相聚合吡咯单体的方法制备了基于聚吡咯(PPy)薄膜的电阻型氨气(NH 3)传感器。通过使用亚硫酸钠对PPy薄膜进行还原,改变了PPy中的极化子含量,研究了PPy还原前后环链上极化子含量对薄膜NH 3敏特性的影响。实验结果表明:由于PPy环链上极化子数量的减少,PPy薄膜的电导率降低。与还原前的高电导率PPy薄膜对比,较低电导率的PPy薄膜在室温下对NH 3具有更高的灵敏度,其灵敏度提高了约6倍。同时,本文提出的基于PPy薄膜的NH 3传感器制备工艺简易、成本低廉并且性能稳定,在农业NH 3监测领域具有很好的应用前景。

A resistive type ammonia(NH 3)gas sensor based on polypyrrole(PPy)film is prepared by the method of in-situ gas phase polymerization of pyrrole monomer.The polaron content in PPy is changed by using sodium sulfite to reduce PPy film,and the effect of polaron content in the ring chain before and after PPy reduction on ammonia sensitivity of the film is investigated.Experimental results show that the PPy film has low conductivity due to the decrease in numbers of polaron on the PPy loop chain.Compared with the PPy film with high conductivity before reduction,the PPy film with lower conductivity has higher sensitivity toward NH 3 at room temperature,and its sensitivity is improved by about 6 times.At the same time,the NH 3 gas sensor based on PPy film is easy to be prepared,low-cost and stable,and has a good application prospect in the field of agricultural NH 3 monitoring.