高分子电阻型湿敏材料的老化机理

Aging Mechanism of Polymer Resistive-type Humidity Sensitive Material

本文以聚苯乙烯磺酸钠为湿敏材料制备了高分子电阻型湿度传感器,研究了其在高温高湿环境下,施加交流电激励后的老化行为。考察了通电电压、通电时间等对传感器响应特性的影响,并对其老化机理进行了探讨。提出通电老化后,湿敏材料在不同湿度下的电阻变化决定于高温高湿环境造成的溶解效应和施加电压后引起的通道效应和离子破坏效应。研究表明,在较高湿度环境下（87~93%RH）,施加800mv的电压可加速湿敏材料的老化过程,使湿度传感器响应信号较快达到稳定,从而有望改善湿度传感器的稳定性。

Resistive-type humidity sensors based on sodium polystyrenesulfonate were prepared,and the aging of the sensors were investigated by applying voltage on the sensors under high humidity and high temperature.The effects of the amplitude of the applied voltage and duration of the aging on the humidity response of the sensors were examined,and the aging mechanism was explored.It is proposed that ＂dissolution effect＂,＂tunneling effect＂ and ＂ion-destroying effect＂ are the main factors affecting the variations in the resistance response of the sensors during aging process.Applying a voltage of 800 mV on the humidity sensors under high humidity（87-93%RH） accelerates the aging of the humidity sensitive material,and thus the resistance response to humidity of the sensors can be stabilized in a short time.In this sense,the electrical aging is expected to improve the long-term stability of polymer resistive-type humidity sensors.